<prompt> Which of the following anti-retroviral drugs is contraindicated in pregnancy?3TC LamivudineNFV NelfinavirAZTEfavirenz  <response>: Ans. d Efavirenz Ref. Harrisons medicine 16th ed., p 320, 1125EFAVIRENZ NNRTI 600 mg qd Not to be taken with a fatty meal Dizziness, insomnia, rash, transaminitis EmbryotoxicCONTRAINDICATIONS TO ABACAVIR Allergies It should not be taken if patient has ever had an allergic reaction to it, because it could cause another severe reaction that may result in death, Breast-feeding, Liver diseases, Pregnancy.Anti-retroviral therapyReverse transcriptase inhibitorsProtease inhibitorsFusion inhibitorsAZT ZidovudineSaquinavirEnfuvirtideDidanosineRitonavirMirovirocZalcitabineNelfinavir StavudineAmprenavir LamivudineFosamprenavirIntegrase InhibitorEmtricitabineLopinavirRaltegnavirAbacavirAtazanavir Tenofovir Delavirdine Nevirapine Efavirenz A. Nucleoside Reverse Transcriptase Inhibitors NRTIs- NRTIs are generally prodrugs that are converted to active forms via phosphorylation. Prevent conversion of viral RNA into dsRNA. Mechanisms and resistance mechanisms similar. Some cross-resistance occurs. Drugs differ in toxicity profiles major side effects are listed below and can cause lactic acidemia.1.Zidovudine ZDV-AZTInhibits reverse transcriptase Used in HAART and in prophylaxis following needlesticks and to prevent maternalfetal transmission Bone marow suppression--dose limiting, may require transfusions2.Didanosine ddl Pancreatitis dose limiting3.Zalcitabine ddC Peripheral neuropathy4.Stavudine c4T Peripheral neuropathy5.Lamivudine 3TC Fewer side effects - mild GI distress, headache Also useful in treating hepatitis BB. Nonnucleoside Reverse Transcriptase Inhibitors NNRTIs-Do not require metabolic activation, no cross-resistance1.NevirapineInhibits reverse transcriptasePrevents maternalfetal transmission2.Delavidine Major drug interactions, possible teratogen3.Efavirenz Major drug interactions, possible teratogenC. Protease Inhibitors-Inhibition of asparate protease HIV-1 protease; a pol gene product; prevents viral assembly1. Indinavir2. Ritonavir3. Saquinavir4. Nelfinavir5. Amprenavir6. LiponavirInhibits asparateGI distress, hyperglycemia, hyperlipidemia, altered fat distribution, nephrolithiasis maintain hydration, indinavir, thrombocytopenia indinavirD. Fusion Inhibitor1. EnfuvirtideBinds gp41, preventing fusion of viral and cellular membranes 