Review of Pharmacology - 9E (2015)

• Clindamycin and erythromycin are static drugs, so can be easily excluded
• Fluoroquinolones follow CDK.
• So, answer is beta lactams as these follows TDK and have long PAE against gram positive cocci.
12. Ans. (d) Ceftobiprole (Ref. Harrison 18th/1247-1248)
Fifth generation cephalosporins (ceftobiprole and ceftaroline) are the only beta-lactams active against MRSA.
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13. Ans. (b) Metronidazole (Ref. KDT 7th/757, CMDT 2015/633)
• For mild cases of pseudomembranous colitis; metronidazole, vancomycin and fidaxomicin (poorly absorbed macrolide)
are equally effective. However, due to cost issues, metronidazole is drug of choice.
• For severe cases or metronidazole unresponsive cases, oral vancomycin is drug of choice.
14. Ans. (c) It can be used for rat bite fever (Ref: KDT 7th/718-720)
Penicillin G
• It is acid labile thus not effective orally.
• Penicillin G has short duration of action. Probenecid inhibits tubular secretion and prolongs its duration of action.
• It has narrow antibacterial spectrum, mainly for gram positive bacteria.
• Penicillin G is drug of choice for infections caused by Treponema like syphilis (T. pallidum) and Rat bite fever (Spirillum
minus).
15. Ans. (b) Piperacillin-tazobactam (Ref: KDT 7th/724)
Drugs active against Pseudomonas are
Penicillins Cephalosporins Aminoglycosides
Carbenicillin Cefoperazone Fluoroquinolones
Ticarcilin Ceftazidime Polypeptides
Mezlocillin
Azlocillin
Piperacillin
16. Ans. (b) Zidovudine (Ref: KDT 7th/803-805)
Anti-HIV drugs effective against HBV are
• L: Lamivudine
• E: Emtricitabine
• T: Tenofovir
Apart from these, other drugs for HBV are
Cefepime
Cefpirome
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• Interferons
• Telbivudine
• Entecavir
• Adefovir
17. Ans. (a) Artesunate (Ref: Harrison 18th/1699-1701)
Drug of choice for severe or complicated malaria is artesunate. For more details, see text.
18. Ans. (b) It has dose-dependent kinetics (Ref. Goodman Gilman 12th/1746-1747)
• Rituximab is a chimeric monoclonal antibody against CD-20 B-cell antigen. It acts by depleting B-cells.
• Rituximab follows first order kinetics. Its clearance remains constant irrespective of plasma concentration. Dosedependent
kinetics means zero-order kinetics i.e. clearance and t ½
change with dose (plasma concentration). Drugs
following zero-order kinetics are warfarin, alcohol, high dose aspirin, tolbutamide, theophylline and phenytoin.
• Infusion-related reactions are seen in approximately 50% of patients receiving first infusion. The incidence decreases
with subsequent infusions. Starting with low doses and pre-treatment with steroids or antihistaminics are the methods
to reduce infusion-related reactions.
• Rituximab may cause reactivation of hepatitis B. Patients should be screened for hepatitis B before initiation of
therapy. It rarely causes reactivation of JC virus leading to progressive multifocal leukoencephalopathy.
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