Nevirapine
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).
http://aidsinfonyc.org/network/access/drugs/nevi.html
http://www.nmia.com/~hivcc/431-nevirapine.html
http://www.viramune.com/ProductInfo/
Last modified: Mon Mar 6 01:00:48 PST 2000