Possible Interaction: Caffeine and Nifedipine

“Because caffeine and nifedipine may have opposing effects on intracellular calcium concentration, a possible interaction between these agents on blood pressure and heart rate was examined.”

“Caffeine pretreatment does not alter the cardiovascular responses to nifedipine but the pressor effect of caffeine is completely reversed by subsequent nifedipine administration.”

“With caffeine pretreatment, nifedipine decreased blood pressure significantly more than with placebo pretreatment.”

“In the presence of nifedipine , pre-exposure to caffeine caused a potentiation of circular muscle, and the initial but not secondary longitudinal muscle contractions to NA.”

“ Nifedipine in addition to caffeine resulted in a reduction of 70%.”

“Dantrolene and nifedipine completely inhibited increases in [Ca2+]i after treatment with caffeine and (±)‐BayK, respectively.”

“Thus, caffeine was pro‐arrhythmogenic immediately following but not > 5 min after application and both CPA and nifedipine pretreatment inhibited such arrhythmogenesis.”

“Identical concentrations of diltiazem but not nifedipine correspondingly suppressed the arrhythmogenic effects of caffeine in whole hearts.”

“3) Depending on the concentration, NTP and caffeine induce cross-desensitization or act additively. (”

“ Nifedipine … caffeine was added to deplete the SR of Ca2+ and eliminate the occurrence of CICR due to ICa,T. Under these conditions, the transients were … Ca2+ entry via T-type channels plays a significant role in excitation-contraction coupling in the developing heart that includes stimulation of CICR.”

“ Nifedipine (1 μm) during refilling reduced the caffeine‐activated ICl(Ca) by 38 ± 5 %.”

“ Caffeine and K(+) responses were blocked by ryanodine (10 microM) and nifedipine (1 microM), respectively.”