A drug follows first-order elimination kinetics with a half-life of 6 hours. What percentage of the drug is eliminated per hour?
- A 6%
- B 11% ✓
- C 16.7%
- D 50%
Correct answer: B. 11%
Explanation
In first-order kinetics, a constant fraction is eliminated per unit time. The elimination rate constant k = 0.693/t½ = 0.693/6 = 0.1155 per hour, approximately 11% per hour. The 16.7% option represents 100%/6, which incorrectly assumes a constant amount eliminated. First-order means fraction, not absolute amount, is constant. This distinction is fundamental and tested.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.