Drugs are used in the prevention and treatment of symptoms and diseases but the drug-drug interactions are one of the major problems in multi-drug therapy. Beta blockers are commonly used in the treatment of hypertension in diabetic patient. Literature showed that risk of retinopathy and cardiovascular disease are more in diabetic hypertensive patients, which may cause morbidity and mortality. Therefore present study is aimed to investigate the safety, reliability of glipizide (antidiabetic drug) and possible drug interaction with propranolol when they were administered as combination treatment. The study was conducted on healthy albino and streptozotocin induced diabetic rats. The hypoglycemic effects of propranolol, glipizide alone and in combination were tested. Results showed that propranolol and glipizide did not have any potential drug interaction on single administration. Though repeated administration of propranolol followed by glipizide enhances hypoglycemic effect of glipizide up to one hour followed reduced hypoglycemic effect of glipizide through out the study period in normal animals but potentiated the hypoglycemic effect of glipizide on diabetic animals. Hence study suggested that the dose and/or frequency of glipizide administration have to be readjusted accordingly when glipizide and propranolol need to be used concomitantly.
