Which of the following statements best defines the clearance of a drug?

• A The fraction of the total body drug load eliminated per unit time
• B The volume of plasma from which drug is completely removed per unit time ✓
• C The amount of drug excreted unchanged in urine per unit time
• D The plasma concentration achieved after distribution is complete

Explanation

Clearance is defined as the volume of plasma irreversibly cleared of drug per unit time, expressed in units such as mL/min or L/h. It equals the rate of elimination divided by plasma concentration and is the single most important determinant of maintenance dose. Option A describes the elimination rate constant, option C describes only renal clearance of unchanged drug and ignores hepatic metabolism, and option D relates to concentration at steady state rather than clearance itself.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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