Review of Pharmacology - 9E (2015)

Chemotherapy B: Antimicrobials for Specific Conditions
• Ritonavir is a protease inhibitor anti-retroviral drug.
• Ritonavir is a microsomal enzyme inhibitor and it interacts with terfenadine, macrolide antibiotics, rifampicin,
warfarin, etc.
• It is predominently eliminated from the body in feces (86% unchanged drug and metabolites) with minor urinary elimination
(11% mostly metabolites).
• Adverse Effects:
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G.I. symptoms are most frequent
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Lipodystrophy syndrome
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Paraesthesia
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Hepatic toxicity
121. Ans. (c) Zidovudine; (d) Cotrimoxazole; (e) Ganciclovir (Ref: CMDT 2010/454)
Drug causing bone marrow supression in patients with HIV infection:
• Zidovudine
• Dapsone
• Trimethoprim/Sulfamethoxazol (Cotrimoxazole)
• Pyrimethamine
• 5-Flucytosine
• Ganciclovir
• Interferon α
• Foscarnet
122. Ans. (b) Ganciclovir; (e) Cidofovir (Ref: KDT 6/e p770, Katzung 11/e p851)
CMV causes retinitis in AIDS patient. Treatment of CMV: IV ganciclovir, Intravitreal ganciclovir, foscarnet, fomivirsen and
cidofovir.
123. Ans. (a) Saquinavir; (c) Nelfinavir (Ref: KDT 6/e p767)
All protease inhibitors end with NAVIR.
124. Ans. (b) It causes marked neurotoxicity (Ref: KDT 6/e p771)
Stavudine is an NRTI that is responsible for maximum peripheral neuropathy.
125. Ans. (a) Lamivudine (Ref: KDT 6/e p772)
126. Ans. (d) Serving as an allosteric inhibitor of HIV reverse transcriptase (Ref: KDT 6/e p772)
Allosteric inhibitor means Non-nucleoside reverse transcriptase inhibitor.
127. Ans. (a) Indinavir (Ref: KDT 6/e p772, 773)
Protease results in the formation of final structural and functional proteins by post translational modification of HIV viral
proteins. Drugs in this group are indinavir, saquinavir, lopinavir, ritonavir, amprenavir etc.
128. Ans. (c) Enfuvirtide (Ref: KDT 6/e p774)
It is a fusion inhibitor useful in the treatment of HIV infections.
129. Ans. (c) Treat the patient with clarithromycin, ethambutol and rifabutin (Ref: KDT 6/e p750)
Mycobacterium avium complex infection is treated with combination of rifabutin, ethambutol and clarithromycin.
130. Ans. (d) Administer zidovudine with lamivudine for 4 weeks (Ref: KDT 6/e p776)
131. Ans. (c) Ganciclovir (Ref: KDT 6/e p770)
• Ganciclovir is the drug of choice for CMV infections.
• It should not be combined with zidovudine because both have bone marrow suppressant property.
132. Ans. (b) Nucleoside reverse transcriptase inhibition (Ref: KDT 6/e p770-771)
133. Ans. (c) Neutropenia (Ref: Katzung 11/e p856)
134. Ans. (b) Emtricitabine (Ref: KDT 6/e p778)
135. Ans. (b) Dose lower for blocking HIV replication than HBV replication (Ref: CMDT 2014/654-655)
• Lamivudine can be used for both HIV as well as HBV. The dose for HIV is 150 mg twice a day whereas a lower dose
of 100 mg daily is used in HBV.
• It should not be used alone as resistance develops quickly.
• Seroconversion from HBeAg positive to anti HBe occurs in only 20% of patients.
Chemotherapy B: General Antimicrobials Pharmacology for Specific Conditions
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