Nifedipine enhances the antidepressant response of sertraline and imipramine

Depression, a bewildering and burdensome illness, is one of the commonest psychiatric diseases. It is expected to be the second leading contributor to Global Disease Burden by 2020. The objective of the study was to determine the effect of nifedipine on the responses of imipramine, sertraline and furosemide in the forced swim test (FST) and tail suspension test (TST) in mice. Groups of mice were housed in iignali metal cages for control, nifedipine + imipramine, nifedipine + sertraline and nifedipine + furosemide groups and were treated for 30 days with placebo, nifedipine (5mg/kg) + imipramine (10mg/kg), nifedipine (5mg/kg) + sertraline (10mg/kg), nifedipine (5mg/kg) + furosemide (10mg/kg) respectively. Experiments were done on Day 1 (acute), 15 (subacute) and 31 (subchronic) when drug doses were not changed except for furosemide which became 100mg/kg. In the FST and also in the TST, results showed that in the test groups, nifedipine potentiated the reduction of the period of immobility of imipramine, sertraline and furosemide significantly when subacute values were compared to acute values (F(3, 20) = 15.47, P < 0.05, < 0.01) and when subchronic values were compared to subacute values (F(3, 20) = 10.53, P < 0.05, < 0.01). DMR post-hoc test showed the nifedipine + imipramine combination as giving the most significant response. In conclusion, results show that subchronic nifedipine administration significantly potentiated the reduction of immobility in the FST and TST of subchronically-administered imipramine, sertraline and furosemide.