Drug interaction: rifampicin and glibenclamide.
BACKGROUND
Rifampicin is a potent inducer of the hepatic microsomal enzyme system. However, the drug has been shown to cause clinically important interactions with many drugs. This study was designed to test the interaction of rifampicin with the oral hypoglycaemic agent glibenclamide.


METHODS
Twenty-nine well-controlled diabetic patients on a combination therapy of diet and glibenclamide, and willing to participate in the trial, received a daily dose of 450 mg (body weight < 50 kg) or 600 mg (body-weight > 50kg) of rifampicin for 10 days.


RESULTS
There was a significant (p < 0.001) worsening of fasting and post-prandial blood sugar after administration of rifampicin. Dose modification of glibenclamide was required in 15 of the 17 patients in whom the diabetes became uncontrolled. Blood sugar normalized by day 6 after stopping rifampicin in all patients.


CONCLUSIONS
Rifampicin and glibenclamide interact. Therefore, necessary dose modifications should be made in order to achieve euglycaemia if these two drugs are given together.
Surekha
V
V
Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
Peter
J V
JV
Jeyaseelan
L
L
Cherian
A M
AM
D000328:Adult; D000368:Aged; D000904:Antibiotics, Antitubercular / Q000008:administration & dosage / Q000494:pharmacology*; D001786:Blood Glucose / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy; D004347:Drug Interactions; D005260:Female; D005905:Glyburide / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D012293:Rifampin / Q000008:administration & dosage / Q000494:pharmacology*
D000904:Antibiotics, Antitubercular; D001786:Blood Glucose; D007004:Hypoglycemic Agents; D005905:Glyburide; D012293:Rifampin