Eirenz is used for treatment of HIV infections. It acts:

ANTIVIRAL DRUGS: Nonnucleoside reverse transcriptase inhibitors (NNis): Nevirapine, Eirenz, Delavirdine* Nevirapine (NVP) and Eirenz (EFV) These are nucleoside unrelated compounds which directly inhibit HlV reverse transcriptase without the need for intracellular phosphorylation. Their locus of action on the enzyme is also different. They are more potent than AZT on HIV -1, but do not inhibit HIV -2. Viral resistance to these drugs develops by point mutation and cross resistance is common among different NNis, but not with Nis or Pis. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:772