+ Description: Nevirapine, whose brand name is Viramune, belongs to a class of drugs known as NNRTIs or non-nucleoside reverse transcriptase inhibitors. Other NNRTIs include delavirdine (Rescriptor) and efavirenz (Sustiva). Nevriapine works by binding directly to reverse transcriptase to inhibit the production of viral DNA. Its site of action on the transcriptase is different from the site of nucleoside analogues.

The mode of action

+ Resistance: Since HIV has no error checking during replication, many copies of the virus are mutations. Some mutations may be resistant to an antiviral, and in this case, when taking an NNRTI by itself, resistance usually develops in a few weeks. Thus it is very important to take nevirapine according to instructions, schedules, and not to reduce or skip doses. Sometimes, is a person become resistant to nevirapine, he might also be resistant to other NNRTIs in a phenomenon known as cross-resistance.

+ Indication: Nevirapine is for use in combination with nucleoside analogues or other anti- HIV drugs such as protease inhibitors for the treatment of HIV-1 infection in adults who have experienced clinical or immunologic deterioration.

+ Dosage: The recommended dosage is 200 mg once a day for the first two weeks and then 400 mg per day (200 mg twice a day) thereafter.

+ Side Effects: Side effects common to all antivirals including nevirapine include headaches, hypertension, nausea, fever, and a sense of feeling ill. For nevirapine, the most common side effect is a skin rash, which develops in about 25% of the people who take the drug. A rare but severe and possibly fatal skin rash known as Stevens-Johnson syndrome developed 7.6% of the patients. Patients developing a severe rash accompanied by fever, blistering, oral lesions, conjunctivitis, swelling, muscle or joint aches, or general malaise should discontinue taking nevirapine.

+ Managing Side Effects: Studies have found some methods to decrease the chance of developing the side effect rash most commonly associated with nevirapine. One recent study found that no one got a rash if antihistamines are taken during the first two weeks of nevirapine treatment. Also, 40-50 mg of the drug prednisone daily during the first two weeks of nevirapine treatment prevented rash development in 82 out of 83 people.

+ Drug Interactions: Nevirapine is processed in the liver and can cause other drugs to be processed too quickly. Thus, nevirapine often lowers the levels of other drugs in the body. Nevirapine reduces the levels of the protease inhibitor Crixivan and greatly reduces the levels of methadone, possibly leading to symptoms of withdrawal. The antibiotic drugs rifabutin and rifampin can lower nerviapine levels in the body while people taking the antifungal fluconazole has an increased chance of the side effect rash.

+ Study: D'Aquila, Richard T., et al. "Nevirapine, Zidovudine, and Didanosine Compared with Zidovudine and Didanosine in Patients with HIV-1 Infection" D'Aquila, Ricard, et al. concluded that using nevirapine with zidovudine and didanosine was an improvement upon the two drug combination therapy in terhms of long-term immunologic and virologic effects, supporting the potential utility of nevirapine in combination therapy regimens.

References used:
+ D'Aquila, Richard T., et al. "Nevirapine, Zidovudine, and Didanosine Compared with Zidovudine and Didanosine in Patients with HIV-1 Infection" Annals of Internal Medicine. June 15, 1996: online(tripcomb.htm).

Last modified: Mon Mar 6 01:00:48 PST 2000