(Med Lett Drugs Ther 2008; 50:94) In Table 1, "Invasive" should be "less" and "more" rather than "no" and "yes" for CT colonography and colonoscopy, respectively. In the conclusion, CT colonography should be changed to "less invasive" rather than "noninvasive".

Modestly elevated C-reactive protein (CRP) concentrations have been associated with an increased risk of coronary heart disease. The recently published and heavily publicized results of the JUPITER trial will lead many patients to ask health care professionals whether they should have a CRP test to see if they should be taking a statin.

Antiviral drugs are an important adjunct to influenza vaccination and can be used for treatment of patients with influenza within 2 days of the onset of illness and for chemoprophylaxis of influenza exposures that occur before or less than 2 weeks after vaccination. Patients who are immunocompromised or immunosuppressed, have pulmonary disease, are elderly or are healthcare workers may also be appropriate candidates for chemoprophylaxis.

Many drugs can cause psychiatric symptoms, but a causal connection is often difficult to establish. Psychiatric symptoms that emerge during drug treatment could also be due to the underlying illness, previously unrecognized psychopathology, or psychosocial factors. The withdrawal of some drugs can cause symptoms such as anxiety, psychosis, delirium, agitation or depression.

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The treatment of choice to prevent emesis due to highand moderate-risk emetogenic drugs used in cancer chemotherapy is aprepitant plus a serotonin receptor antagonist plus dexamethasone. Four serotonin receptor antagonists are available in the US in intravenous (IV) formulations for prevention of nausea and vomiting due to cancer chemotherapy, and 3 of these are also available for oral use. Now the FDA has approved one of these, granisetron, in a transdermal formulation (Sancuso - ProStrakan).

(Med Lett Drugs Ther 2008; 50:94) In table 1, "Invasive" should be "less" and "more" rather than "no" and "yes" for CT colonography and colonoscopy, respectively.

The FDA has approved the marketing of alvimopan (Entereg - Adolor/GlaxoSmithKline), a selective muopioid receptor antagonist, for oral treatment of postoperative ileus after bowel resection. The only other drug in this class available in the US is subcutaneously injected methylnaltrexone (Relistor), which is approved for treatment of opioid-induced constipation in patients with advanced illness receiving palliative care.

Options in screening for colon cancer include fecal occult blood tests, flexible sigmoidoscopy, colonoscopy, computed tomography (CT) colonography and fecal DNA tests. Since the last Medical Letter article on this subject, more data have become available on colonography.

Health care professionals may be asked about lowvoltage electronic devices now being used to diagnose and/or treat a number of health problems. Most are galvanometers that measure skin resistance to an electric current. The FDA classifies "devices that use resistance measurements to diagnose and treat various diseases" as Class III devices that require FDA approval prior to marketing. None of the devices reviewed here has such approval.

The FDA has added a boxed warning to fluoroquinolone package inserts about tendon injuries that may occur as a result of their use. Tendinitis or tendon rupture may occur rarely with systemic use of any fluoroquinolone, either while the drug is being taken or for up to several months afterwards.

Fluoroquinolone-related tendon injury is rare; estimates for its incidence in the general population range from 0.14% to 0.4%. The risk is higher for patients >60 years old and for those taking corticosteroids. For patients with organ transplants, the incidence may be as high as 15%.1 A case-control study in Italy involving 22,194 cases of non-traumatic tendinitis and 104,906 controls found that fluoroquinolone use was significantly associated with tendon disorders in general (OR 1.7; 95% CI 1.4-2.0), tendon rupture (OR 1.3; 95% CI 1.0-1.8), and Achilles tendon rupture (OR 4.1; 95% CI 1.8-9.6). Achilles tendon rupture occurred with fluoroquinolone treatment in one of every 5989 patients in general and in one of every 1638 patients >60 years old.2

Widespread use of fluoroquinolones, particularly for treatment of respiratory infections, has produced substantial bacterial resistance to this class of drugs and has been associated with an increase in the incidence and severity of Clostridium difficile disease.3 Even when bacterial pneumonia is considered a likely possibility, other drugs are generally preferred, at least in non-elderly, otherwise healthy patients.4

1. F Muzi et al. Fluoroquinolones-induced tendinitis and tendon rupture in kidney transplant recipients: 2 cases and a review of the literature.Transplant Proc 2007; 39:1673.
2. G Corrao et al. Evidence of tendinitis provoked by fluoroquinolone treatment: a case-control study. Drug Saf 2006; 29:889.
3. Treatment of Clostridium difficile-associated disease (CDAD). Med Lett Drugs Ther 2006; 48:89.
4. Drugs for community-acquired bacterial pneumonia. Med Lett Drugs Ther 2007; 49:62.

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(Med Lett Drugs Ther 2008; 50:91) In the Clinical Studies section, the complete response rate with chlorambucil for CLL was 2% (not 24%).

Some tumor necrosis factor (TNF) inhibitors are being promoted on the internet directly to the public for use in psoriasis (www.yahoo.com).

Depression occurs in up to 20% of pregnant women, and the use of selective serotonin reuptake inhibitors (SSRIs) in these women has been increasing. Maternal depression has itself been associated with intrauterine growth problems and low birth weight, so the risks of exposure to antidepressants during pregnancy must be weighed against the risks of untreated depression, which also include self-harm, poor bonding and poor parenting. SSRIs available in the US for treatment of depression include citalopram (Celexa, and others), escitalopram (Lexapro), fluoxetine (Prozac, and others), paroxetine (Paxil, and others) and sertraline (Zoloft).

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Bendamustine HCl (Treanda - Cephalon), an unusual DNA-alkylating agent that has been used in Europe for many years to treat lymphoma, has now been approved by the FDA for treatment of chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphoma (NHL).

The US Preventive Services Task Force (USPSTF) has recently concluded that available evidence is insufficient to assess the balance between potential benefits and harms of using the prostate-specific antigen (PSA) to screen men < 75 years old for prostate cancer and has recommended against screening men > 75 years old.

Major orthopedic surgery creates a prothrombotic state by causing tissue injury during the operation and requiring relative immobilization during recovery. Without thromboprophylaxis, 40-60% of patients undergoing major knee or hip surgery develop venographically detectable deep vein thrombosis (DVT) and 1 in 300 undergoing total hip replacement will have a symptomatic pulmonary embolism (PE). Thromboprophylaxis reduces the incidence of venous thromboembolism (VTE), but it also can cause bleeding. New guidelines for prevention of VTE have recently been published.

Inhaled drugs for asthma are available in the US mainly in pressurized metered-dose inhalers (MDIs), which require a propellant, and dry powder inhalers, which do not. The chlorofluorocarbon (CFC) propellants in MDIs are being replaced by hydrofluoroalkane (HFA) propellants for environmental reasons: CFCs contribute to the depletion of the ozone layer. December 31, 2008 will be the last day that albuterol MDIs using CFC propellants can be sold in the US. The FDA is expected to announce a termination date for other CFC-containing products in the near future.

Three HFA albuterol inhalers and one HFA levalbuterol inhaler have been approved by the FDA. None is available generically. HFA inhalers require priming — firing 4 puffs into the air (3 with ProAir) — the first time they are used, and after 2 weeks of non-use (3 days with Xopenex HFA).

In general, HFA sprays taste different, are less forceful, and are warmer and mistier than CFC sprays. Some patients may have to be reassured that they are getting enough of their medication, but actually the smaller particles of the HFA sprays may reach the lungs more readily than CFC sprays.

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The FDA has approved the marketing of certolizumab pegol (Cimzia - UCB), a tumor necrosis factor (TNF) blocker, for treatment of moderate to severe Crohn's disease refractory to conventional treatment. It is the third TNF blocker approved for this indication.

A recent letter to the editor of the Annals of Internal Medicine documented a single case of myopathy apparently due to an interaction between simvastatin (Zocor, and others) and green tea. Since it became available generically, simvastatin has surpassed atorvastatin (Lipitor) as the best selling statin. As such, it is probably the most common cause of statin-induced myopathy, which is often a result of drug interactions.

Melamine present in infant formula and other milk products has been associated with widespread illness and some deaths among infants in China. It was also identified in pet food sold in North America after a large number of pets became ill and some died. In both the infants and the pets, renal injury appeared to be the cause.1

Melamine (C₃H₆N₆) is a heterocyclic compound, two-thirds nitrogen by weight, that is slightly soluble in water. When combined with formaldehyde, it forms melamine resin, which has a wide variety of industrial applications including the manufacturing of kitchenware, whiteboards and laminate flooring.1 Because of its nitrogen content, melamine has been illegally added to products such as milk, wheat gluten and rice protein to factitiously boost the apparent protein content; common assays for protein content do not distinguish between amino-acid nitrogen and non-protein nitrogen.

Melamine itself is relatively nontoxic; the FDA has established, based on an extrapolation from studies in rats, a tolerable daily intake of 0.63 mg/kg/day.1 However, the combination of melamine with cyanuric acid (a water disinfectant and/or impurity associated with melamine production that itself is also nontoxic) results in the formation of insoluble crystals that precipitate in renal tubules following ingestion and may cause acute renal failure.2-4 Infants may be especially sensitive to this mechanism of toxicity.

Treatment of humans or animals poisoned with these compounds is largely supportive. Hemodialysis may be indicated, depending on the degree of renal failure. Whether hemodialysis removes melamine or related compounds is unknown.

1. U.S. Food and Drug Administration. Interim safety and risk accessment of melamine and its analogues in food for humans. October 3, 2008. Available at www.cfsan.fda. gov/~dms/melamra3.html. Accessed October 14, 2008.
2. CA Brown et al. Outbreaks of renal failure associated with melamine and cyanuric acid in dogs and cats in 2004 and 2007. J Vet Diagn Invest 2007;19:525.
3. RL Dobson et al. Identification and characterization of toxicity of contaminants in pet food leading to an outbreak of renal toxicity in cats and dogs. Toxicol Sci 2008; 106:251.
4. World Health Organization. Melamine and cyanuric acid: toxicity, preliminary risk assessment and guidance on levels in food. September 25, 2008. Available at www.who.int/foodsafety/fs_management/Melamine.pdf. Accessed October 14, 2008.

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Annual immunization against influenza A and B is the most effective method of preventing infection and has been shown to reduce influenza complications. Changes this year include a vaccine with three new influenza antigens and expanded age criteria to include all children 6 months to 18 years of age. An upcoming issue of The Medical Letter will review drugs for prophylaxis and treatment of influenza.

The FDA has approved the use of the 5α-reductase inhibitor dutasteride (Avodart - GlaxoSmithKline) together with the alpha₁-blocker tamsulosin (Flomax - Boehringer Ingelheim) for treatment of benign prostatic hyperplasia (BPH). Use of an alpha1-blocker with a 5α-reductase inhibitor has been a common practice for years, but FDA approval of a particular combination permits the manufacturers to add an indication for it in both package inserts, recommend dosage for combination use, and advertise the benefits of using the 2 drugs together.

Clevidipine (Cleviprex - The Medicines Company), a dihydropyridine calcium channel blocker (CCB), has been approved by the FDA for intravenous (IV) use in lowering high blood pressure. It is the second IV CCB to be marketed in the US; nicardipine has been available in an IV formulation (Cardene IV) for more than 10 years. Like IV nicardipine, clevidipine will probably be used mainly for urgent treatment of hypertension in intensive care units, operating rooms and emergency departments.

The FDA has approved the marketing of the corticosteroid ciclesonide (Alvesco - Sepracor) in a hydrofluoroalkane (HFA) metered-dose inhaler formulation for maintenance treatment of asthma in patients >12 years old. Ciclesonide is also available in the US as a nasal spray for allergic rhinitis (Omnaris), and has been available for asthma in Europe since 2003.

The bisphosphonate risedronate (Actonel - Procter & Gamble) was recently approved by the FDA in a 150- mg once-monthly oral tablet for prevention and treatment of postmenopausal osteoporosis. The drug is also available for the same indication in 5-mg daily, 35-mg weekly and 75-mg twice-monthly tablets.

Sunscreens are an important component of photoprotection. A new definition of their effectiveness has been proposed, and some issues have arisen concerning their safety.

The FDA has issued an update (August 18, 2008; www.fda.gov) on occurrences of acute pancreatitis in patients with diabetes taking exenatide (Byetta – Amylin/Lilly). The latest update, which follows an FDA Alert in October 2007, reports 6 cases of hemorrhagic or necrotizing pancreatitis with 2 deaths in patients taking the drug. Whether pancreatitis occurs more often in patients taking exenatide than in patients with diabetes not taking exenatide is not clear.1

Given by subcutaneous injection, exenatide is a synthetic peptide that stimulates release of insulin from pancreatic beta cells.2 It is FDA-approved as adjunctive therapy in patients with type 2 diabetes. In addition to potentiating insulin release, exenatide slows gastric emptying, which may cause nausea and sometimes vomiting. The presenting symptoms of acute pancreatitis typically are nausea, vomiting and severe upper abdominal pain. Severe abdominal pain is not a usual side effect of exenatide. If pancreatitis is suspected in a patient taking exenatide, the drug should be discontinued promptly, and should not be restarted after recovery.

1. SR Ahmad and J Swann. Exenatide and rare adverse events. N Engl J Med 2008; 358:1970.
2. Exenatide (Byetta) for type 2 diabetes. Med Lett Drugs Ther 2005; 47:45.

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Aliskiren (Tekturna - Novartis), the first direct renin inhibitor for treatment of hypertension, has been approved for use in a fixed-dose combination with the diuretic hydrochlorothiazide (Tekturna HCT - Novartis). Many angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are also available in fixed-dose combinations with hydrochlorothiazide (HCTZ).

Rotarix, an oral live-attenuated rotavirus vaccine, has been approved by the FDA for prevention of rotavirus gastroenteritis in infants and children. Rota-Shield was withdrawn from the market because of an association with intussusception. RotaTeq, an oral live, human-bovine reassortant rotavirus vaccine, is recommended by the American Academy of Pediatrics as a routine immunization.

In recent months, both the lay media and some medical experts have raised concerns about the effectiveness and safety of ezetimibe, a widely used drug that prevents absorption of cholesterol from the GI tract. Ezetimibe is available alone as Zetia and in combination with 10, 20, 40 and 80 mg of simvastatin (Zocor, and others) as Vytorin.

The FDA has approved the marketing of a new device for delivering lidocaine to the skin of children undergoing a venipuncture or intravenous (IV) line placement. Zingo (Anesiva) is a powder intradermal injection system.

The antiplatelet agents aspirin and clopidogrel (Plavix, and others) are used in most patients undergoing percutaneous coronary intervention (PCI) to prevent stent thrombosis and to reduce the occurrence of peri-, post-procedural and late cardiovascular events. Despite a large number of randomized trials of these agents in such patients, the optimal dosage and duration of treatment with these drugs, and whether other drugs should be added, is unclear.

The article in the July 14th issue contained an error in the last sentence of the last paragraph beginning on page 55. The instrument's reading is determined not by the degree of protrusion of the tympanic membrane, but rather by its mobility.

Duloxetine (Cymbalta - Lilly) is the second drug to be approved by the FDA for treatment of fibromyalgia. Pregabalin (Lyrica), which is also approved for treatment of neuropathic pain and epilepsy, was the first. Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) that is already marketed for treatment of depression and diabetic neuropathy.

The most common cause of travelers' diarrhea, usually a self-limited illness without fever lasting several days, is infection with noninvasive enterotoxigenic (ETEC) or enteroaggregative (EAEC) strains of Escherichia coli. Campylobacter, Shigella, Salmonella, Aeromonas, viruses and parasites are less common.

The American Heart Association (AHA) recently published a statement saying that it would be reasonable to obtain an electrocardiogram (ECG) in children being evaluated for stimulant drug therapy for attention deficit hyperactivity disorder (ADHD). A subsequent news release in conjunction with the American Academy of Pediatrics provided a clarification, saying that it would be reasonable to consider obtaining an ECG in such children.

The U.S. Advisory Committee on Immunization Practices has recommended administration of the quadrivalent conjugated polysaccharide meningococcal vaccine (Menactra – Sanofi Pasteur) to all persons 11 to 18 years old, particularly those entering high school and college freshmen living in dormitories.1,2 The peak incidence of meningococcal disease, after early childhood, occurs in the 15-19 year-old age group. The conjugate vaccine is more immunogenic than the meningococcal capsular polysaccharide vaccine (Menommune – Sanofi Pasteur).

ADVERSE EFFECTS — The most common adverse reactions with the conjugate vaccine have been headache, fatigue and malaise, in addition to pain, redness and induration at the injection site. Guillain-Barré syndrome has occurred rarely.3

CONCLUSION — Previously unvaccinated children starting high school or going away to college this fall should receive a single dose of meningococcal conjugate vaccine (Menactra).

1. Centers for Disease Control and Prevention (CDC). Advisory Committee on Immunization Practices. Revised recommendations of the Advisory Committee on Immunization Practices to vaccinate all persons aged 11-18 years with meningococcal conjugate vaccine. MMWR Morb Mortal Wkly Rep 2007; 56:794.
2. Menactra: a meningococcal conjugate vaccine. Med Lett Drugs Ther 2005; 47:29.
3. Centers for Disease Control and Prevention (CDC). Update: Guillain-Barre syndrome among recipients of Menactra meningococcal conjugate vaccine — United States, October 2005-February 2006. MMWR Morb Mortal Wkly Rep 2006; 55:364.

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The nicotine receptor partial agonist varenicline (Chantix - Pfizer) appears to be the most effective drug available to treat tobacco dependence, but the FDA has added a warning to the package insert about neuropsychiatric symptoms and exacerbations of preexisting psychiatric illness associated with its use. Agitation, hostility, depressed mood, suicidal ideation and suicidal behavior have been reported as postmarketing adverse events in patients who took varenicline and stopped smoking and in those who took the drug and continued to smoke.

Lubiprostone (Amitiza), which was previously approved for treatment of chronic idiopathic constipation in adults, has now also been approved in a lower dose for use in women with irritable bowel syndrome with constipation (IBS-C). Since tegaserod (Zelnorm) has been withdrawn from the market,2 lubiprostone is the only drug approved by the FDA for treatment of this common condition.

Bupropion (Wellbutrin - GlaxoSmithKline, and others) is a norepinephrine and dopamine reuptake inhibitor that has been a useful antidepressant because, unlike some other antidepressants, it does not cause sexual dysfunction, weight gain or sedation. Some patients who were switched from Wellbutrin to a generic alternative have reported worsening side effects and relapse of previously controlled depressive symptoms.1 Most of the complaints have come from patients switched from Wellbutrin XL 300 mg to the generic 300-mg formulation of extended-release bupropion marketed by Teva (Budeprion XL).2 In 2007, about 1 million prescriptions per month were dispensed for extended-release formulations of bupropion; about 40% of these were written for Budeprion XL 300 mg.

The EarCheck Middle Ear Monitor (Innovia Medical) is a device marketed to consumers for home detection of middle-ear effusion (MEE) in children.

Patients are asking physicians about an article on the front page of the June 15th New York Times, in which some prostate cancer experts were quoted as suggesting that men 55 and older might be well advised to take finasteride (Proscar, and others) to prevent prostate cancer.

Fluvoxamine maleate, a selective serotonin reuptake inhibitor (SSRI) that has been available for many years in an immediate-release formulation (Luvox, and others) for treatment of obsessive-compulsive disorder (OCD) in children and adults, has now been approved by the FDA in an extended-release formulation (Luvox CR - Jazz Pharmaceuticals) for treatment of OCD and social anxiety disorder (SAD) in adults.

Olopatadine 0.6% nasal spray (Patanase - Alcon) has been approved by the FDA for treatment of seasonal allergic rhinitis in patients ≥ 12 years old. An H1-antihistamine with mast-cell stabilizing activity, olopatadine is already marketed for treatment of allergic conjunctivitis in a 0.1% solution as Patanol and in a 0.2% solution as Pataday. Azelastine (Astelin), another H1-antihistamine with mast-cell stabilizing activity, has been available for intranasal treatment of allergic rhinitis since 1997.

The goal for drug therapy of type 2 diabetes is achieving and maintaining a near-normal glycated hemoglobin (HbA_1C) concentration without inducing hypoglycemia; the target has generally been an HbA_1C of 6.5-7.0% or lower. Whether treating to this level prevents macrovascular (cardiovascular) events has been unclear. Now, 2 large randomized, double-blind trials in patients with long-standing diabetes and at high risk for cardiovascular disease have found no decrease in macrovascular events with intensive glucose control.

The ACCORD trial in about 10,000 patients found that patients intensively treated with anti-hyperglycemic drugs, including frequent use of thiazolidinediones, mostly rosiglitazone (Avandia), and insulin, with an HbA_1C target of 6.0% (actual median HbA_1C 6.4%) did not obtain a significant reduction in major cardiovascular events (the primary endpoint) over a period of 3.5 years. The trial was stopped early because of an unexpected increase in all-cause mortality (257 deaths vs. 203) in intensively treated patients compared to patients with an HbA_1C target of 7.0-7.9% (actual median HbA_1C 7.5%). The etiology of the higher mortality is unclear.1

The ADVANCE trial in about 11,000 similar patients treated to an HbA_1C target of 6.5% with a sulfonylurea-based regimen, and infrequent use of thiazolidinediones, also found no decrease in macrovascular events, but no increase in all-cause mortality.2

Whether intensive glycemic control would reduce macrovascular events in patients at lower risk has not been established.

1. The ACCORD Study Group. Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med 2008; 358:2545.
2. The ADVANCE Collaborative Group. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med 2008; 358:2560.

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The FDA has approved an oral, fixed-dose combination (Treximet - GlaxoSmithKline) of the selective serotonin receptor agonist ("triptan") sumatriptan (Imitrex) and the nonsteroidal anti-inflammatory drug (NSAID) naproxen sodium (Anaprox, and others) for acute treatment of migraine attacks.

Cataracts are the leading cause of blindness worldwide because cataract surgery is not available to most people in developing countries.

Etravirine (Intelence - Tibotec), a new non-nucleoside reverse transcriptase inhibitor (NNRTI), has received fast-track FDA approval for use in combination therapy in treatment-experienced adults who have HIV-1 infection resistant to an NNRTI and other antiretroviral agents.

A reader expressed disappointment that our recent listing of “Some Warfarin Drug Interactions”1 did not include acetaminophen. Perhaps it should have. Acetaminophen can increase the anticoagulant effect of warfarin, particularly with continued use, but it does so inconsistently. The mechanism of this interaction has not been established, but may be related to an acetaminophen metabolite inhibiting vitamin K-epoxide reductase, the target for warfarin’s anticoagulant effect.2

Patient susceptibility varies, possibly on a genetic basis; occasional use of acetaminophen generally has little or no effect on the international normalized ratio (INR) in patients on chronic warfarin therapy, but in some, even a few grams of the drug may cause a dramatic increase in INR. One study in healthy subjects found no effect of acetaminophen 4 g per day for 2 weeks, while another study in patients with the same acetaminophen dose for the same period of time found a moderate increase in INR.3,4 It might be prudent to monitor INR in patients on chronic warfarin therapy more closely than usual when they take more than 2 g per day of acetaminophen for more than a few days.

1. Pharmacogenetic-based dosing of warfarin. Med Lett Drugs Ther 2008; 50:39.
2. HH Thijssen et al. Paracetamol (acetaminophen) warfarin interaction: NAPQI, the toxic metabolite of paracetamol, is an inhibitor of enzymes in the vitamin K cycle. Thromb Haemost 2004; 92:797.
3. D Kwan et al. The effects of acetaminophen on pharmacokinetics and pharmacodynamics of warfarin. J Clin Pharmacol 1999; 39:68.
4. I Mahe et al. Paracetamol: A haemorrhagic risk factor in patients on warfarin. Br J Clin Pharmacol 2005; 59:371.

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Spinal decompression machines offer a motorized form of mechanical traction. These devices, which are widely advertised to the public as a noninvasive alternative to surgery, are claimed to relieve low back pain by decompressing discs, improving the flow of nutrients into the disc and rehydrating dried-out discs. Devices cleared by the FDA based on substantial similarity to previously approved power traction devices include the Accu- Spina System, DRS System, DRX9000, Lordex Traction Unit, Spinal Health Elite, SpineMED Decompression Table, SpineRx-LDM and VAX-D Therapeutic Table.

Bevacizumab (Avastin - Genentech) is a recombinant humanized monoclonal antibody that binds to vascular endothelial growth factor and prevents it from binding to receptors on endothelial cells, inhibiting formation of new blood vessels. Previously approved by the FDA for use in combination regimens for first-line treatment of metastatic colon cancer and metastatic non-small cell lung cancer, and used off-label for treatment of agerelated macular degeneration, it has now also been approved by the FDA for use in combination with paclitaxel (Taxol, and others) for first-line treatment of HER2-negative metastatic breast cancer.

Sapropterin (Kuvan - BioMarin) has been approved by the FDA to reduce phenylalanine plasma concentrations in patients with phenylketonuria (PKU). PKU is a rare genetic disorder (it occurs in 1 in 8000 Caucasian and 1 in 50,000 African-American newborns) caused by a deficiency of phenylalanine hydroxylase (PAH) the resulting high levels of the amino acid in blood and urine lead to cognitive, behavioral and other neurological complications.

The US Centers for Disease Control and Prevention (CDC) has reported that measles outbreaks have occurred in New York City, California and Arizona in 2008, and additional cases have been confirmed in Michigan, Wisconsin, Hawaii, New York State, Pennsylvania, Illinois and Virginia (CDC Health Advisory, May 1, 2008). To date, 63 of the 64 infected patients were unvaccinated, and 54 of the cases were associated with importation of the disease. Both measles infection and vaccination (2 doses at least 28 days apart, with the first dose no earlier than 12 months of age) generally provide lifelong immunity.Patients >12 months old with no evidence of immunity (not born before 1957, no convincing history of clinical measles, no documentation of vaccination, and no laboratory evidence of immunity) should be vaccinated with MMR or monovalent measles vaccine. In an outbreak, children 6-12 months old can also be vaccinated, but they will still need 2 subsequent doses after the age of 12 months to be fully immunized.¹ Contraindications to the attenuated live-virus vaccine include pregnancy, immunosuppressive therapy, leukemia or lymphoma, and congenital or acquired immunodeficiency. Transient fever and/or rash can occur after vaccination.

1. Committee on Infectious Diseases in LK Pickering et al eds, 2006 Red Book: Report of the Committee on Infectious Diseases 27th ed, Elk Grove, Ill: American Academy of Pediatrics 2006, page 446.

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The May 5, 2008 article (Med Lett Drugs Ther 2008; 50:34) on the approval of natalizumab (Tysabri) for treatment of Crohn's disease in the "Adverse Effects" section on page 35 included the statement: "post-marketing hepatotoxicity, sometimes fatal or requiring liver transplantation, has occurred." Actually, no fatal hepatotoxicity or liver transplantation has been reported to date. The FDA warning about post-marketing hepatotoxicity with Tysabri that was the basis for our statement said: "The combination of transaminase elevations and elevated bilirubin without evidence of obstruction is recognized as an important predictor of severe liver injury that may lead to [emphasis added] death or the need for a liver transplant in some patients." Also, in the last sentence of the Conclusion, we should have said: "Because of the risk of serious hepatic toxicity and the rare but even more serious risk of developing progressive multifocal leukoencephalopathy, it should be used only in patients who have not responded to other drugs, including a TNF inhibitor." The italicized words should be substituted for "it is FDA-approved for use."

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The FDA has approved the marketing of desvenlafaxine (Pristiq - Wyeth), the main active metabolite of venlafaxine (Effexor, and others - Wyeth), for treatment of major depressive disorder. Venlafaxine, a norepinephrine and serotonin reuptake inhibitor (SNRI), is available generically as an immediate-release tablet. Venlafaxine extended-release capsules (Effexor XR) are scheduled to go off-patent in 2010.

Warfarin sodium (Coumadin, and others) and other coumarin anticoagulants prevent thrombosis, but patient response is highly variable and overanticoagulation can lead to hemorrhage. Genotyping patients for single nucleotide polymorphisms (SNPs) that affect coumarin metabolism and sensitivity may help clinicians estimate the therapeutic warfarin dose. The FDA has added a note to warfarin labeling recommending lowrange doses for patients with such genetic variations. Commercial tests for these variants are now available and cost about $500 per test.

The drug of choice for patients who require parenteral treatment for malaria is IV artesunate, which is available now from the CDC Malaria Branch (M-F, 8 AM-4:30 PM eastern time, 770-488-7788 or, after hours, 770-488-7100). Artesunate appears to be more effective than quinine1 and safer than quinidine, the other parenteral alternatives in the US. The CDC has supplies of artesunate in Atlanta and in 8 quarantine stations in major airports around the US. It will release the drug for appropriate patients (severe disease or unable to take oral drugs) if it can be supplied as quickly as quinidine, or if quinidine has failed, been poorly tolerated, or is contraindicated.

The herbal artemisinin derivatives artemether and artesunate are used worldwide for treatment of malaria caused by Plasmodium falciparum, but have not been marketed in the US.2,3 About 1500 cases of malaria are diagnosed each year in the US in returning travelers, and about 5% of these have severe disease.4

Artesunate is generally given over 3 days in 2.4 mg/kg doses at 0, 12, 24 and 48 hours. It should be accompanied as soon as possible by an oral drug such as atovaquone/proguanil (Malarone), doxycycline (Vibramycin, and others; not for children <8 years old), clindamycin (Cleocin, and others) or mefloquine (Lariam, and others).

1. A Dondorp et al. South East Asian Quinine Artesunate Malaria Trial (SEAQUAMAT) Artesunate versus quinine for treatment of severe falciparum malaria: a randomised trial. Lancet 2005; 366:717.
2. Drugs for parasitic infections. New Rochelle, NY: The Medical Letter; 2007:34.
3. NJ White. Qinghaosu (artemisinin): the price of success. Science 2008; 320:330.
4. PJ Rosenthal. Artesunate for the treatment of severe falciparum malaria. N Engl J Med 2008; 358:1829.

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Ciclesonide (Omnaris - Sepracor/Nycomed), a once daily corticosteroid nasal spray, is now available for treatment of seasonal allergic rhinitis (SAR) in adults and children ≥6 years old and for perennial allergic rhinitis (PAR) in those ≥12 years old. An orally inhaled formulation of ciclesonide (Alvesco) was recently approved by the FDA for maintenance treatment of asthma, and will be reviewed in a future issue of The Medical Letter

Natalizumab (Tysabri - Elan and Biogen) is a monoclonal antibody approved for induction and maintenance treatment of moderate to severe Crohn's disease (CD) refractory to conventional therapies and inhibitors of tumor necrosis factor (TNF). Initially approved in 2004 for the treatment of multiple sclerosis (MS), natalizumab was temporarily withdrawn from the market after 3 patients developed progressive multifocal leukoencephalopathy (PML). It is now available for treatment of both MS and CD through a restricted distribution program.

Colesevelam (Welchol - Daiichi Sankyo - Med Lett Drugs Ther 2000; 42:102), a bile-acid sequestrant used to lower LDL cholesterol, has been approved by the FDA as an adjunct to diet and exercise in the treatment of type 2 diabetes. In unpublished studies summarized in the package insert, patients with type 2 diabetes taking metformin (Glucophage, and others), a sulfonylurea or insulin (each as either monotherapy or in combination with other anti-diabetic agents) were given colesevelam 3800 mg per day or placebo; colesevelam significantly reduced glycosylated hemoglobin (A1c) by about 0.5% more than placebo in all three trials. The mechanism is unclear.

Colesevelam can cause constipation, nausea and dyspepsia, increase serum triglyceride concentrations, and interfere with absorption of other oral drugs. One month's treatment with Welchol obtained from drugstore.com would cost about $200. Medical Letter consultants are not enthusiastic about prescribing it for this indication.

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Advertisements for atorvastatin (Lipitor), the market leader facing generic competition, have been in the news recently in the US. Lovastatin, pravastatin and simvastatin are all available generically at a much lower retail price or lower co-pay than atorvastatin.

The nonsteroidal anti-inflammatory drug (NSAID) diclofenac, has been approved by the FDA in a 1% topical gel formulation (Voltaren Gel - Endo) for treatment of osteoarthritis (OA). A 3% topical diclofenac gel (Solaraze) is currently approved for treatment of actinic keratoses, but not for topical use on joints. No other topical NSAIDs are approved by the FDA for OA. A diclofenac patch (Flector) was recently approved by the FDA for treatment of pain due to minor strains, sprains and contusions.

Genetic Test for Carbamazepine-Induced Stevens-Johnson Syndrome Carbamazepine (Tegretol, Carbatrol, Equetro, and others), which is now used to treat not only epilepsy but also trigeminal neuralgia and manic episodes in patients with bipolar disorder,1 is a known cause of Stevens-Johnson syndrome (SJS). The incidence of carbamazepine-induced SJS in countries with mainly white populations is 1 to 6 per 10,000 new users of the drug, but Asian patients have a 10-fold higher incidence of this reaction. An association has been found between the human leukocyte antigen (HLA)-B*1502 allele and carbamazepine-induced SJS in a Chinese population.2 This allele occurs almost exclusively in Asians.3,4 The FDA is now recommending that Asian patients be tested for genetic susceptibility to carbamazepine-induced SJS before starting the drug. The genetic test should be available in most clinical chemistry labs.

1. Extended-release carbamazepine (Equetro) for bipolar disorder. Med Lett Drugs Ther 2005; 47:27.
2. WH Chung et al. Medical genetics: a marker for Stevens- Johnson syndrome. Nature 2004; 428:486.
3. C Lonjou et al. A marker for Stevens-Johnson syndrome. . . : ethnicity matters. Pharmacogenomics J 2006; 6:265.
4. A Alfirevic et al. HLA-B locus in Caucasian patients with carbamazepine hypersensitivity. Pharmacogenomics 2006; 7:813.

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The FDA has approved the marketing of a second fixed-dose combination of extended-release niacin (Niaspan) with a generic statin. Niaspan/simvastatin (Simcor - Abbott) is approved for use in patients with hypercholesterolemia or mixed dyslipidemia (high LDL-cholesterol, low HDL-cholesterol and high serum triglycerides). Niaspan/lovastatin (Advicor) was marketed previously for the same indications.

Nilotinib (Tasigna - Novartis), a tyrosine kinase inhibitor, has been approved by the FDA for treatment of Philadelphia chromosome-positive (Ph+) chronic or accelerated phase chronic myelogenous leukemia (CML) in patients resistant to or intolerant of imatinib (Gleevec).

The phosphodiesterase type 5 (PDE5) inhibitor tadalafil (Cialis - Lilly) is now being promoted for once daily treatment of erectile dysfunction. Tadalafil differs from sildenafil (Viagra) and vardenafil (Levitra), the other PDE5 inhibitors marketed for erectile dysfunction in the US, in having a much longer duration of action.

The CDC recently reported that fluoroquinoloneresistant strains of Neisseria meningitidis have been detected for the first time in the US in an area around the border of North Dakota and Minnesota (CDC. MMWR, Feb 22, 2008). These isolates were all serogroup B, for which meningococcal vaccines (Med Lett Drugs Ther 2005; 47:29) do not offer protection. Since many laboratories do not test N. meningitidis for antimicrobial susceptibility, it is possible that such resistance is more widespread.

A single oral dose of ciprofloxacin (Cipro, and others) 500 mg has been used for prophylaxis after close contact with infected patients. Oral rifampin (Rifadin, and others) 600 mg (10 mg/kg for children) q12h for 2 days, a single IM injection of ceftriaxone (Rocephin, and others) 250 mg (125 mg for children), or a single oral dose of azithromycin (Zithromax, and others) 500 mg (10 mg/kg for children) are reasonable alternatives.

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Cholinesterase inhibitors are now used routinely in patients with dementia. Rivastigmine transdermal system (Exelon Patch - Novartis), a patch formulation of the cholinesterase inhibitor rivastigmine tartrate, has been approved by the FDA for treatment of mild to moderate dementia associated with Alzheimer's or Parkinson's disease. An oral formulation of rivastigmine tartrate has been available in the US since 2000,2 but gastrointestinal adverse effects possibly related to rapidly rising serum concentrations have limited its use.

Treatment options for snoring and obstructive sleep apnea (OSA) now include, in addition to lifestyle remedies such as weight loss and avoidance of alcohol in the evening, mechanical devices, injection of botulinum toxin into the soft palate and a variety of ENT surgical outpatient procedures. Palatal implants (Pillar procedure - Restore Medical Inc) have been approved by the FDA for treatment of snoring and OSA.

Nebivolol (Bystolic - Forest) is a new beta-blocker that has been approved by the FDA for treatment of hypertension. It has been marketed in Europe since 1999 for treatment of hypertension and heart failure.

Celiac disease is a chronic autoimmune disorder caused by a genetic intolerance to gluten that occurs in about 1% of the population. The main form of treatment is a lifelong gluten-free diet.

Retapamulin (re-tap'-a-mue'-lin; Altabax - Glaxo SmithKline) is a topical antibiotic recently approved by the FDA for treatment of bullous and non-bullous impetigo due to Streptococcus pyogenes and methicillin-susceptible Staphylococcus aureus. It is available as a 1% ointment by prescription only.

The FDA has approved the marketing of sinecatechins (Veregen - Bradley/Medigene), a botanical drug product, for treatment of external genital and perianal warts. Sinecatechins is a water extract of green tea leaves from Camellia sinensis. It is a mixture of catechins and other green tea components.

Sevelamer carbonate (Renvela – Genzyme), a buffered form of the anion-exchange resin sevelamer hydrochloride (Renagel – Genzyme),1 has been approved by the FDA for use in patients with chronic kidney disease on dialysis. According to the manufacturer, Renvela will replace Renagel, which has been shown to induce or exacerbate metabolic acidosis in patients on dialysis. Two randomized, crossover studies found the two sevelamer salts equivalent in their ability to lower serum phosphate.2,3 Patients taking the carbonate had higher serum bicarbonate concentrations and fewer gastrointestinal adverse effects. Sevelamer carbonate, which is available in 800-mg tablets, can be substituted for the hydrochloride salt gram for gram. Recent studies in patients beginning hemodialysis have suggested a possible mortality benefit for sevelamer compared to less expensive calcium- based phosphate binders,4,5 but some critics are skeptical.6

1. Phosphate binders. Med Lett Drugs Ther 2006; 48:15.
2. J Delmez et al. A randomized, double-blind, crossover design study of sevelamer hydrochloride and sevelamer carbonate in patients on hemodialysis. Clin Nephrol 2007; 68:386.
3. S Fan et al. Renvela (sevelamer carbonate) powder and Renagel (sevelamer hydrochloride) tablets: report of a randomized, cross-over study in chronic kidney disease (CKD) patients on hemodialysis (poster). American Society of Nephrology Renal Week. October 31- November 5 2007. San Francisco.
4. GA Block et al. Mortality effect of coronary calcification and phosphate binder choice in incident hemodialysis patients. Kidney Int 2007; 71:438.
5. AM Borzecki et al. Survival in end stage renal disease: calcium carbonate vs. sevelamer. J Clin Pharm Ther 2007; 32:617.
6. J Silver. The details bedevil DCOR. Kidney Int 2007; 72:1041.

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A combination of the corticosteroid budesonide and the long-acting beta₂-agonist formoterol (Symbicort - AstraZeneca) has become available in a metered dose inhaler for long-term maintenance treatment of asthma in patients ≥ 12 years old. A combination product that contains fluticasone propionate and salmeterol (Advair) is already available for this indication in the US. Neither one of these combinations is approved for acute treatment of asthma symptoms. A dry powder inhaler formulation of Symbicort has been available in Europe and Canada for several years.

The FDA has approved azithromycin 1% ophthalmic solution (AzaSite - Inspire) for treatment of bacterial conjunctivitis in patients > 1 year old. It is formulated, according to the manufacturer, in a controlled-release delivery system that keeps the drug in the eye for several hours.

The FDA recently advised health care professionals and consumers not to use a number of dietary supplements found to contain the phosphodiesterase-5 inhibitor sildenafil (Viagra) or an analog of the drug (www.fda.gov). Although the effects of sildenafil may be noticeable (in men), the presence of other, possibly more toxic adulterants in dietary supplements may be more difficult or impossible to detect.

Other drugs previously found in dietary supplements have included lovastatin (Mevacor, and others), estrogen, alprazolam (Xanax, and others), indomethacin (Indocin, and others) and warfarin (Coumadin, and others). Aristolochic acid in Chinese herbal weight loss products caused acute renal failure in about 100 women in Belgium; at least 70 of them required dialysis or transplantation, and at least 18 developed urothelial cancer (Med Lett Drugs Ther 2002; 44:84).

Dietary supplements do not require FDA approval before marketing. The agency does have the power to remove mislabeled or adulterated products from store shelves, but the burden of discovery and proof is entirely on the government.

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Doripenem (Doribax - Ortho-McNeil Janssen), an intravenous (IV) carbapenem antibiotic with a spectrum of activity similar to that of imipenem and meropenem, has been approved by the FDA for treatment of complicated intra-abdominal and urinary tract infections. Use of doripenem for treatment of nosocomial pneumonia, including ventilator-associated pneumonia, is still under FDA review.

Ixabepilone (ix ab ep' i lone; Ixempra - Bristol-Myers Squibb), a semisynthetic epothilone analog, has been approved by the FDA for treatment of advanced breast cancer. It is indicated for use in combination with capecitabine (Xeloda - Roche) for treatment of locally advanced or metastatic breast cancer after failure of an anthracycline such as doxorubicin (Adriamycin) and a taxane such as paclitaxel (Taxol, and others). It is also approved as monotherapy for treatment of metastatic or locally advanced breast cancer after an anthracycline, a taxane and capecitabine have failed.

An unpublished 2-year randomized study (ENHANCE) on the effect of adding ezetimibe 10 mg to simvastatin 80 mg in 720 patients with heterozygous familial hypercholesterolemia has been in the news recently. About 80% of these patients had previously been treated with statins. The primary endpoint was the change in the intima-media thickness (IMT) of the carotid artery (baseline 0.68 and 0.69 mm); the IMT increased by 0.0111 mm with ezetimibe plus simvastatin and 0.0058 mm with simvastatin 80 mg alone (p=0.29). The ezetimibe- simvastatin combination lowered LDL-C by 58% compared to 41% lowering with simvastatin alone (p<0.01). The study was not powered to assess cardiovascular events; cardiovascular deaths occurred in 2 patients treated with both drugs and 1 on simvastatin alone.

Ezetimibe, an inhibitor of cholesterol absorption, is available both alone (Zetia) and in combination with 10, 20, 40 and 80 mg of simvastatin (Vytorin). No data have been published on the effect of ezetimibe on cardiovascular events with or without simvastatin. Whether addition of ezetimibe to a statin is as effective as raising the dose of the statin in decreasing the number of cardiovascular events remains to be determined in larger studies that are underway.

Neither Zetia or Vytorin is recommended for initial treatment of hypercholesterolemia.

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Diclofenac epolamine patch 1.3% (Flector Patch - Alpharma), a topical formulation of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac, has been approved by the FDA for topical treatment of acute pain due to minor strains, sprains and contusions. It is the first topical NSAID patch approved in the US. A diclofenac patch has been used in Europe since 1993. Diclofenac sodium (Voltaren, and others) is available in the US as an oral tablet, in a 1% gel for treatment of osteoarthritis (to be reviewed in a future issue), in a 3% gel (Solaraze) for treatment of actinic keratoses, and in an ophthalmic formulation.

Raltegravir (Isentress - Merck), the first in a new class of oral HIV drugs called HIV-1 integrase strand transfer inhibitors (InSTI), has received accelerated FDA approval for use in combination therapy for treatment-experienced adults infected with HIV-1 strains resistant to multiple antiretroviral agents.

Maraviroc (Selzentry - Pfizer), the first CCR5 (CC chemokine receptor 5) antagonist has received the same FDA approval but is restricted to use in adults with CCR5-tropic HIV-1 ("R5 virus"). A commercial assay is available for R5 tropism.

Cetirizine (Zyrtec, and others) and cetirizine/pseudoephedrine (Zyrtec-D) are becoming available without a prescription this month for treatment of allergic rhinitis and urticaria in adults and children. Cetirizine is the second of the second-generation H1-antihistamines to become available over the counter. Loratadine (Claritin, and others) was the first.

Cetirizine has been shown to be more effective than loratadine in suppressing histamine-induced wheals in healthy volunteers (W Carey et al. Drugs Exp Clin Res 2002; 28:243), but no well-controlled clinical trials have established that any second-generation H1-antihistamine is more effective overall than any other (M Plaut and MD Valentine. N Engl J Med 2005; 353:1934).

Cetirizine may be mildly sedating in some patients, but it is significantly less sedating than first-generation H1-antihistamines such as diphenhydramine (Benadryl, and others) or chlorpheniramine (Chlor-Trimeton, and others), which have been available without a prescription for many years. Its safety in young children is better documented than that of any other first- or second-generation H1-antihistamine (Treat Guidel Med Lett 2007; 5:71).

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