Category: Anti Viral

Combination Interferon For Chronic Hepatitis C Virus

Hepatitis C Virus

Pegylated interferon (peg-interferon) alfa-2a (Pegasys®, Roche), combined with ribavirin (Rebetol tablet, Schering), is now available for the treatment of patients with chronic hepatitis C virus (HCV). This combination is intended for adults with compensated liver disease and who have not previously taken alpha interferons. (Please see the December 2002 issue of P&T for a review of peg-interferon.)

More patients who received peg-interferon alfa-2a plus ribavirin showed a sustained response to the virus, with the absence of detectable HCV ribonucleic acid (RNA) six months after discontinuation of therapy, compared with patients who received inter-feron-alfa-2b plus generic ribavirin or peg-inter-feron alfa-2a alone.

A once-weekly dose was well tolerated and resulted in improvements in the rate of sustained virologic response.

Valacyclovir for Reducing Spread of Genital Herpes

Generic Valacyclovir HCl (Valtrex® Caplets, GlaxoSmithKline) has been approved to reduce the risk of heterosexual transmission of genital herpes to susceptible partners with healthy immune systems when used as suppressive therapy in combination with safer sex practices. The drug was first approved for the treatment of genital herpes in 1995.

Many individuals have no or only minimal signs or symptoms and may transmit the virus during sexual contact when they show no signs of active infection, such as genital lesions.

The FDA revised the labeling for Canadian Valtrex® on the basis of an international, double-blind, placebo-controlled eight-month clinical trial involving approximately 1,500 monogamous, heterosexual couples. At the beginning of the study, only one member in each couple had evidence of genital herpes. The results showed a 48% reduction in herpes simplex virus acquisition, although individual results may have varied on the basis of safer sex practices.

The medication has caused kidney and nervous system problems (e.g., aggressive behavior, unsteady or shaky movements, confusion, speech problems, hallucinations, seizures, and coma) in some patients with pre-existing renal disease and in elderly patients with impaired renal function. Patients should inform their health care providers if they have had kidney problems or other medical conditions before taking Valtrex®.

South Africa Rejects AIDS Drug for Women

The South African government has rejected a common treatment used to reduce the transmission of the AIDS virus by pregnant women to their babies. Instead, it has recommended a 28-week regimen that combines nevirapine (Viramune generic) and generic zidovudine (Medication Retrovir® AZT, GlaxoSmithKline), a more complex schedule that might reach fewer women.

The Medicines Control Council recommended against giving pregnant, HIV-positive women a single dose of the drug nevirapine just before childbirth, even though the practice has become common in Africa. The Council ruled that mothers who took the drug would be likely to develop drug resistance to anti-retroviral therapy and that nevirapine was more effective when used in combination with other drugs.

Health experts have condemned the decision as another example of South Africa’s reluctance to confront the AIDS epidemic head-on, even though more than 5 million of its citizens are infected with HIV.

Although the regimen recommended by the regulators is theoretically better, the risk of creating a generation of infected children is thought to outweigh the risk of creating drug resistance.

The country’s register of medicines claims that treating pregnant women with single doses of nevirapine during childbirth increases the likelihood that antiretroviral therapy would not work for them when they become sick later in life.

The World Health Organization supports the treatment of pregnant women with nevirapine alone. In many African nations, pregnant women wait too long to begin a 28-week course of therapy. Usually, a shorter course of antiretrovirals or a single dose of nevirapine for the mother and baby are the only options. Although a single dose of nevirapine increases drug resistance, it reduces the risk of transmission from 30% to nearly 15%.

New Help for Hep C

When interferon-based treatment does not appear to be working in patients with hepatitis C virus (HCV) infection, a new once-daily, antiviral oral treatment might be the answer. NM283 (Idenix Pharmaceuticals), which passed its first human clinical trial with flying colors, metabolizes to a form that inhibits HCV RNA polymerase. In a multicenter trial, 82 patients completed treatment; 68 patients received NM283 and 14 received placebo. All of the patients had chronic HCV infection (genotype 1 …

Combination Drugs Fight HIV

Two new combinations of medications have been approved to treat human immunodeficiency virus (HIV) infection. Patients with HIV infection and acquired immunodeficiency syndrome (AIDS) usually need to take three or more drugs from different classes simultaneously.

Epzicom™ (GlaxoSmithKline) combines abacavir 600 mg (Ziagen®) and generic lamivudine 300 mg (Drug Epivir®). Truvada™ (Gilead) is a fixed-dose combination of tenofovir disoproxil fumarate 300 mg (Viread®) and emtricitabine 200 mg (Emtriva®).

Counterfeit Flu Drug Seized

Customs agents intercepted more than 50 shipments of counterfeit Tamiflu (Roche), the antiviral drug being stockpiled in anticipation of a deadly bird flu pandemic.

The first package was intercepted on November 26 at an air mail facility near San Francisco International Airport. Since then, agents have seized 51 separate packages, each containing up to 50 counterfeit capsules labeled generic Tamiflu generic.

The fake drugs had only trace elements of the drug but none of Tamiflu’s active ingredients. Initial tests indicated some vitamin C in the capsules. Information on the packages was written in Chinese, but it is unclear where the drugs originated. They were sent by Asian suppliers to individuals who placed orders over the Internet. None of the intercepted shipments has been bound for doctors or hospitals.

Agents became suspicious because because no generic version of Tamiflu is available.

The Roche Web site says the company does not advocate buying this medication from the Internet. Patients should consult with a health care professional before buying Tamiflu and should make sure that they obtain it from a “reliable source.”

The FDA will seek criminal charges if it finds any U.S. businesses were involved in the fake drug shipments.

First Generic HIV/AIDS Capsule

Generic HIV

Aurobindo Pharma’s zidovudine, the first generic capsule dosage form to treat HIV/AIDS, is now approved for patients in the U.S. The tablet and oral solution dosage forms of generic zidovudine were previously approved for sale in the U.S. when the patent on those dosage forms expired in September 2005.

The approval of the capsule formulation follows the expiration of Glaxo-SmithKline’s patent on its capsule form of the product marketed under the trade name Canadian Retrovir.