An experimental study on the effect of felodipine on serum electrolytes and lithium concentration in albino rabbits

Abstract

Objectives: To study the effect of felodipine, a calcium channel blocker, on concurrent administration with lithium carbonate on serum electrolytes and lithium in Albino rabbits. Material and Methods: Albino rabbits weighing 2.5 – 3 kg were divided in three group of ten each and were administered lithium carbonate and/or felodipine in suspension made of gum tragacanth daily for eight days. Blood was drawn from marginal ear vein after 24 hours of first dose and then at 28th day of drug/s administration for acute and chronic effects respectively. Serum was separated out and supernatant was decanted after centrifugation at 3000 rpm. Serum sodium, potassium and/or lithium were estimated using flame photometry. Heart rate was measured by heart transducer and polygraph. Mortality was observed till a week after last dose administration in this study. Results: Acute effects of co-administration of felodipine and lithium resulted in highly significant decrease in heat rate but no fall in serum potassium and insignificant increase in sodium levels from the baseline values. On chronic co-administration, significant decrease in heat rate was maintained without any significant change in serum electrolytes and lithium levels from base line. No mortality was observed in the group treated with felodipine and lithium simultaneously. Conclusions: Felodipine with lithium co-administration minimally affect the serum electrolytes and lithium concentration and thus appears relatively safe for co-administration.Key words: Bipolar-disorder, Felodipine, Hypertension, Lithium