FDA Safety Labeling Changes: Viramune, Copegus, MalaroneApr 20, 2005 | Medscape
The U.S. Food and Drug Administration (FDA) approved in February revisions to safety labeling to notify healthcare professionals of the following changes: use of nevirapine tablets and oral suspension may cause serious hepatotoxicity and skin reactions, and intensive monitoring is therefore required during early therapy; use of ribavirin plus peginterferon alfa-2a therapy is contraindicated in patients with decompensated liver disease; and use of atovaquone plus proguanil HCl tablets has been associated with rare cases of anaphylaxis.
Nevirapine (Viramune) May Cause Serious Hepatotoxicity, Skin Reactions
On Feb. 24, the FDA approved revisions to the safety labeling for nevirapine tablets and oral suspension (Viramune, made by Boehringer Ingelheim Pharmaceuticals, Inc) to warn of the risk of potentially life-threatening hepatotoxicity and skin reactions associated with their use.
The FDA emphasizes the need for intensive monitoring of patients for signs and symptoms of these reactions during the first 18 weeks of nevirapine therapy, particularly during the high-risk initial six-week period.
Liver function tests (LFTs) should be performed immediately in patients who exhibit signs or symptoms suggestive of hepatitis and/or hypersensitivity reaction, and in all patients who develop a rash during the first 18 weeks of treatment.
Symptoms of hepatitis may include fatigue, malaise, anorexia, nausea, jaundice, bilirubinemia, acholic stools, lever tenderness, or hepatomegaly. A diagnosis of hepatotoxicity should be considered in this setting even if LFT results are normal or alternative diagnoses are possible.
In addition, the FDA notes that the 200-mg daily regimen for nevirapine must be strictly adhered to during the two-week lead-in period.
Nevirapine therapy should be discontinued and not resumed in patients who experience severe hepatic, skin, or hypersensitivity reactions. According to the FDA, hepatic injury has progressed in some patients despite discontinuation of therapy.
Nevirapine is indicated for use in combination with other antiretroviral agents for the treatment of HIV-1 infection.
Ribavirin/Peginterferon Alfa-2a (Copegus/Pegasys) Contraindicated in Patients With Decompensated Liver Disease
On Feb. 25, the FDA approved revisions to the safety labeling for ribavirin tablets (Copegus, made by Hoffmann La-Roche Inc) to advise of contraindications and warnings associated with its use.
Use of ribavirin plus peginterferon alfa-2a combination therapy is contraindicated in patients with chronic hepatitis C virus (HCV) infection, with or without HIV coinfection, who demonstrate hepatic decompensation (Child-Pugh score > 6; class B and C) prior to or during treatment. Its use is also contraindicated in patients with autoimmune hepatitis.
The FDA also warns that patients with HCV infection and cirrhosis may be at risk of hepatic decompensation and death when treated with alpha interferons, including peginterferon alfa-2a (Pegasys, made by Hoffmann La-Roche, Inc). This risk may be increased in cirrhotic patients coinfected with HIV who are receiving highly active antiretroviral therapy.
Ribavirin in combination with peginterferon alfa-2a is indicated for the treatment of adults with chronic HCV infection who have compensated liver disease and who have not been previously been treated with alpha interferons.
The FDA notes that ribavirin monotherapy is not effective for the treatment of chronic HCV infection and should not be used.
Atovaquone Plus Proguanil Tablets May Cause Anaphylaxis
On Feb. 27, the FDA approved revisions to atovaquone plus proguanil HCl tablets and pediatric tablets (Malarone, made by GlaxoSmithKline) to warn of rare cases of anaphylaxis associated with their use.
Adverse events reported during worldwide postapproval use also include cutaneous reactions ranging from rash, photosensitivity, and urticaria to rare cases of erythema multiforme and Stevens-Johnson syndrome.
Use of the combination product is contraindicated in patients with known hypersensitivity to atovaquone or proguanil or any component of the formulation.
Atovaquone plus proguanil HCl tablets are indicated for the prophylaxis and treatment of Plasmodium falciparum malaria.