JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD Pharm. D III Year PHARMACOTHERAPEUTICS - II Previous Question Paper (October/November - 2019 - R08)

The standard treatment regimen for tuberculosis (TB) follows the DOTS strategy, consisting of an intensive phase and a continuation phase. The intensive phase lasts for 2 months and includes Isoniazid (H), Rifampicin (R), Pyrazinamide (Z), and Ethambutol (E). The continuation phase lasts for 4 months and includes Isoniazid and Rifampicin.

Safety monitoring parameters for these drugs include:

• Isoniazid: Monitor for peripheral neuropathy (supplement with pyridoxine) and hepatotoxicity (check baseline and monthly liver function tests (LFTs) if symptomatic).
• Rifampicin: Monitor for hepatotoxicity and orange-red discoloration of body fluids (counseling is required).
• Pyrazinamide: Monitor for hyperuricemia (gout symptoms) and hepatotoxicity.
• Ethambutol: Monitor for optic neuritis; patients should be advised to report any changes in visual acuity or color discrimination.

Surgical antimicrobial prophylaxis aims to prevent surgical site infections (SSIs) by reducing the microbial load at the incision site. The choice of antibiotic depends on the type of surgery and the likely pathogens involved.

• Cefazolin: The first-line agent for most clean and clean-contaminated surgeries (e.g., cardiac, orthopedic, and general surgery) due to its activity against skin flora like Staphylococcus aureus and Staphylococcus epidermidis.
• Cefoxitin or Cefotetan: Often used in colorectal surgeries to provide coverage against anaerobic bacteria in addition to gram-negative aerobes.
• Metronidazole: Frequently combined with a cephalosporin (like Cefazolin) to provide anaerobic coverage in abdominal surgeries.
• Vancomycin: Reserved for patients with severe beta-lactam allergies or in institutions with a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA).

Prophylaxis should be administered within 60 minutes prior to the incision to ensure adequate tissue concentrations.