Telmisartan is an antihypertensive drug that inhibits angiotensin II receptors type AT1. Studies showed drug interactions with different potentials. This study was intended to investigate the role of some active ingredients acting on influx, efflux and metabolizing enzymes in intestinal absorption of telmisartan prior to hepatic-pass effect. Intestinal perfusion with venous sampling technique was applied in rats by perfusing telmisartan in intestinal lumen, and measuring its concentration and amount versus time.