<p>Lamivudine, Zidovudine &amp; Nevirapine synergistically reduce the viral resistance and inhibit reverse transcriptase via DNA chain termination.<br />
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<strong>Lamivudine</strong>:&nbsp;Intracellularly, Lamivudine is phosphorylated to its active 5&rsquo;-triphosphate metabolite, Lamivudine triphosphate (L-TP). The principal mode of action of L-TP is inhibition of reverse transcription (RT) via DNA chain termination after incorporation of the nucleoside analogue. Following oral administration, Lamivudine is rapidly absorbed and extensively distributed. Binding to plasma protein is low.<br />
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<strong>Zidovudine</strong>:&nbsp;Intracellularly, Zidovudine is phosphorylated to its active 5&rsquo;-triphosphate metabolite, Zidovudine triphosphate (ZDV-TP). The principal mode of action of ZDV-TP is inhibition of RT via DNA chain termination after incorporation of the nucleoside analogue. Following oral administration, Zidovudine is rapidly absorbed and extensively distributed. Binding to plasma protein is low. Zidovudine is eliminated primarily by hepatic metabolism.<br />
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<strong>Nevirapine</strong>: Nevirapine binds directly to reverse transcriptase (RT) and blocks the RNA-dependent and DNA-dependent DNA polymerase activities by causing a disruption of the enzyme&#39;s catalytic site. The activity of nevirapine does not compete with template or nucleoside triphosphates.</p>