Acetaminophen (paracetamol) pharmacokinetics in contraceptive pill-using Myanmar women

ABSTRACT

Acetaminophen (paracetamol) pharmacokinetic study was made on a total of 16 healthy adult Myanmar women of reproductive age, half of whom were pretreated chronically for 6 month with an oral contraceptive steroid (OCS), namely, Combination 5. Single oral dose (930 mg) of acetaminophen showed similar extent of maximum plasma acetaminophen concentration in either group. However, the OCS causes significant effect (p<0.05) on plasma acetaminophen resulting in shortening of half-life by 21.6 per cent and augmentation of clearance by 5.9 per cent. The OCS affected predominantly the sulphate conjugation of acetaminophen. In regimen requiring repeated dosing, acetaminophen should be administered more frequently in the pill-users.