Antonietta is taking antitubercular, the most common adverse effect she may be experiencing is:
A. Red-orange discoloration of urine
B. Hypersensitivity
C. Hepatotoxicity
D. CHF
Correct Answer: C. Hepatotoxicity
Hepatotoxicity is the most common side effect associated with antitubercular agents. All first-line antitubercular medications, rifampin, isoniazid, pyrazinamide, and ethambutol can exert hepatotoxic effects. A continual rise in liver functions test should prompt discontinuation of treatment. Liver function tests should be monitored routinely as rifampin, isoniazid, pyrazinamide, and ethambutol all may exert hepatotoxic effects.
Option A: Orange discoloration is a side effect of rifampin but not with antitubercular in general. Distribution of the drug is high throughout the body, and reaches effective concentrations in many organs and body fluids, including the cerebrospinal fluid. Since the substance itself is red, this high distribution is the reason for the orange-red color of the saliva, tears, sweat, urine, and feces.
Option B: Adverse drug reaction to tuberculous chemotherapy is not an uncommon problem. Usually, it occurs with single drugs and can be treated easily with minimal intervention. Immediate-type allergic reactions from antituberculosis drugs are not rare and not related to disease or treatment characteristics.
Option D: Aminoglycoside induced nephrotoxicity is reversible when stopping the medication. Renal toxicity depends on the patient if any underlying renal disease is present, and on the dose of the medication being administered. Renal insufficiency is avoidable in most patients.