What is the Primary site for drug excretion?

Sites of drug elimination are the sites from which a drug gets excreted out of our body.

A majority of the drugs are mainly excreted via the KIDNEYS ie, urine.

Other sites are

LUNGS - volatile drugs like general anaesthetics, alcohol ,

BILE - via entero-hepatic circulation eg- phenolphthalein, doxycycline, cefoperozone ,

INTESTINES - via p-glycoprotein, passive diffusion for the absorbed drugs and their metabolites, and directly for the unabsorbable antacids, laxatives etc.,

SKIN - via sweat especially arsenic and heavy metals like Mercury,

SALIVA- iodides, lead etc.

MILK - various antithyroid drugs, antibiotics etc.