The effect of amlodipine on blood glucose level and its interaction with oral hypoglycemic drugs in albino rabbits.

Background: Amlodipine used as many cardiac conditions esp in hypertension. Diabetes affects cardiovascular system adversely. So this study was done to see effect of amlodipine on blood glucose level and its interaction with commonly used oral hypoglycemic agents in diabetic & non diabetic albino rabbits. Methods: Rabbits were divided into nine groups of 6 rabbits in each group. I and II group were non-diabetic given normal saline and amlodipine respectively. Group III to IX were made diabetic by using alloxan monohydrate (150mg/kg i.p.) & given normal saline, glimepiride, metformin, pioglitazone, amlodipine + glimepiride, amlodipine + metformin and amlodipine + pioglitazone respectively. All drugs were given orally once daily for 7 day except group VII, VIII and IX in which glimepiride, metformin and pioglitazone were added on 7th day. After GTT blood glucose level were measured at 0, 1, 2 and 6 hours on 7th day in all groups by using spectrophotometer. Results: After 7 days of treatment the amlodipine produced significant hyperglycemia in normal rabbits. Amlodipine on combination, causes significant decreased in hypoglycemic effect of glimepiride, significant increased the hypoglycemic effect of metformin, while no significant changes in hypoglycemic effects of pioglitazone in diabetic rabbits. Conclusion: The present study shows that amlodipine causes hyperglycemia in normal rabbits. Amlodipine significantly altered hypoglycemic effect of glimepiride and metformin as compared to control group. If these finding are true to human beings then amlodipine should be use cautiously in diabetic patient on oral hypoglycemic drugs.

Effect of anxiolytics on blood sugar level in rabbits.

Anxiety disorders are more prevalent not only in normal individuals but also in diabetes mellitus. Diazepam, a benzodiazepine, and buspirone, an azaspirodecanedione, are the most often prescribed anxiolytics. Present study was aimed to investigate the effect of diazepam and buspirone on the blood sugar levels in rabbits. Buspirone (0.5 mg/kg/day p.o.) and diazepam (0.6 mg/kg/day p.o.) did not affect the glucose levels in rabbits even after one month of treatment. Present findings suggest that these two anxiolytics have minimal effect on blood sugar control.

Mechanism of haloperidol-induced miosis.

Haloperidol administration (iv) has been shown to produce miosis in dogs. In the present study on rabbits, haloperidol administration (iv) produced dose-related miosis but when administered intracerebroventricularly, it failed to produce any change in pupillary size. Higher degree of miosis was observed when haloperidol was administered directly into the anterior chamber of eye. Haloperidol pretreatment failed to significantly modify the mydriasis produced by phenylephrine or atropine. These observations suggest that the miosis produced by haloperidol is a peripheral effect, and also that the miosis is not mediated through the blockade of alpha adrenoceptors of radial muscles or stimulation of cholinoceptors of circular muscles of iris.