Non-nucleoside reverse transcriptase inhibitors
NNRTIs are used in combination with other antiretrovirals to treat
HIV infection. The three agents in this class include:
nevirapine. (See Combining antiretroviral drugs.)
Efavirenz and delavirdine are highly protein-bound
after absorp-tion and distribution, and nevirapine is widely distributed
through-out the body. All three drugs are metabolized by the cytochrome P-450 liver
enzyme system and excreted in urine and stool.
Nevirapine and delavirdine bind to the reverse
transcriptase en-zyme, preventing it from exerting its effect, and thus
preventing HIV replication. Efavirenz competes for the enzyme through
NNRTIs are used in combination with other
antiretrovirals in HIV treatment; nevirapine is specifically indicated for the
patient whose clinical condition and immune status have deteriorated.
NNRTIs may be responsible for many drug
Nevirapine may decrease the activity of protease inhibitors and hormonal
contraceptives; these drugs shouldn’t be used together.
Delavirdine may increase levels of benzodiazepines, clar-ithromycin,
rifabutin, saquinavir, and warfarin; it may also signifi-cantly increase
concentrations of indinavir, requiring a decrease in the indinavir dosage.
The indinavir dosage will need to be increased when given with
Nevirapine has been associated with a severe rash that may be
life-threatening. If a rash occurs, discontinue the drug. (See Ad-verse reactions to NNRTIs.)