This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
Chloroquine is given in high loading dose because of: 
Select and explain. 
A. High volume of distribution, B. Poor GIT absorption, C. High first pass metabolism, D. All
A: High volume of distribution
Answer: A: High volume of distribution 
Explanation: Pharmacokinetics :Oral absorption of chloroquine is excellent. About 50% gets bound in the plasma. It has high affinity for melanin and nuclear chromatin: gets tightly bound to these tissue constituents and is concentrated in liver, spleen, kidney, lungs (several hundred-fold), skin, leucocytes and some other tissues. Its selective accumulation in retina is responsible for the ocular toxicity seen with prolonged use. Absorption after i.m. injection is also good. Chloroquine is paly metabolized by liver and slowly excreted in urine. The early plasma tYz varies from 3-10 days. Because of tight tissue binding, small amounts persist in the body with a terminal Ph of 1-2 months. ESSENTIALS OF PHARMACOLOGY page no 822