Lacidipine: effects on vascular pressor responses throughout the dosage interval in normotensive subjects.
OBJECTIVE
To assess the duration and consistency of the pharmacological activity of the dihydropyridine calcium antagonist drug, lacidipine.


METHODS
Eight healthy normotensive young males participated in a double-blind randomised crossover comparison of single and multiple doses (for 2 weeks) of lacidipine and placebo. The calcium antagonist effects were quantified at 2, 6 and 24 h post dose by the extent of the attenuation of the pressor responses to the intravenous administration of the vasoconstrictors angiotensin II and noradrenaline.


RESULTS
After 2 weeks of treatment, lacidipine consistently and significantly attenuated the pressor responses to both agents at 2 h post dose. At 6 and 24 h post dose there was a significant and progressive decline in the effectiveness of lacidipine in attenuating the pressor responses and for the response to angiotensin II there was no statistically significant effect at either 6 or 24 h post dose.


CONCLUSIONS
These results indicate that there is an obvious 'peak' in the pharmacological activity of lacidipine at about 2 h post dose and that this activity is not fully and consistently maintained throughout 24 h.
University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, Scotland.
S
S
Ueda
R
R
Donnelly
V
V
Panfilov
A D
AD
Morris
H L
HL
Elliott
D000328:Adult; D000804:Angiotensin II / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D002121:Calcium Channel Blockers / Q000009:adverse effects / Q000494:pharmacology*; D018592:Cross-Over Studies; D004095:Dihydropyridines / Q000009:adverse effects / Q000494:pharmacology*; D004311:Double-Blind Method; D005076:Exanthema / Q000139:chemically induced; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; C060285:lacidipine; D009638:Norepinephrine