Effects of verapamil and nifedipine on psychomotor performance in human subjects.
The present study was undertaken to evaluate the effects of two structurally dissimilar calcium channel blockers, verapamil (a phenylalkylamine) in a single dose of 40 and 80 mg, and nifedipine (a dihydropyridine) in a single dose of 10 and 15 mg, on psychomotor performance and higher mental functions in human volunteers. Placebo and diazepam (5 mg) were used as negative and positive controls respectively. For evaluating these functions, tests employed were arithmetic ability, visual and auditory reaction time, letter (alphabet) cancellation, rapid fire arithmetic deviation and short term memory for playing cards. Careful record was kept of the heart rate, blood pressure and side effects of the therapy, each time the psychomotor tests were performed. Verapamil, both in 40 and 80 mg dose, was found to impair the performance of subjects to a significant extent in auditory reaction time, letter cancellation and short term memory. These effects were similar to those observed with administration of diazepam. With nifedipine, impairment in performance was observed only in rapid arithmetic deviation test. Thus, calcium channel antagonists, specially verapamil, impaired psychomotor performance of human subjects in our study.
Department of Pharmacology, LTM Medical College, Sion, Bombay.
V S
VS
Jaguste
V N
VN
Dadkar
H L
HL
Dhar
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003975:Diazepam / Q000494:pharmacology; D004341:Drug Evaluation; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006613:Higher Nervous Activity / Q000187:drug effects*; D006801:Humans; D008297:Male; D009543:Nifedipine / Q000008:administration & dosage / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects*; D014700:Verapamil / Q000008:administration & dosage / Q000494:pharmacology*
D014700:Verapamil; D009543:Nifedipine; D003975:Diazepam