Subcutaneous drugs total drug clearance

Chloroquine is well absorbed after oral, intramuscular, and subcutaneous administration. It distributes relatively slowly into a very large apparent volume (over 100 L/kg) and is extensively sequestered in tissues, particularly liver, spleen, kidney, lung, and to a lesser extent, brain and spinal cord. Chloroquine binds moderately (60%) to plasma proteins and is biotransformed via hepatic CYPs to two active metabolites, desethylchloroquine and bisdesethylchloroquine. Renal clearance of chloroquine is about half of total clearance. Unchanged chloroquine and its major metabolites account for >50% and 25% of urinary drug products, respectively, and their renal excretion is increased by urine acidification. 

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