Possible Interaction: Trifluoperazine and Calcium Supplement

“It is potentiated by the addition of calcium ions , and dissociated by the CaM inhibitor, trifluoperazine.”

“… calcium transient was increased about five times at … eighteen times at pH 7.4 by trifluoperazine (0.30 mM), and two to three times at pH 6.9 by compound 48/80 (0.…-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8, 2.13 mM) and verapamil (1.81 mM).”

“ Trifluoperazine (stelazine), an agent which selectively binds calmodulin, inhibits phospholipase activity induced by calcium.”

“Most reports suggest TFP also increases calcium affinity of CaM. To compare TFP binding to apo CaM and (Ca2+)4‐CaM and explore differential effects on the N‐ and C‐domains of CaM, stoichiometric TFP titrations of CaM were monitored by 15N‐HSQC NMR.”

“…,TFP … calcium affinity at most levels tested; this is similar to the effect of many IQ‐motifs on CaM. However, at the highest level tested, TFP … of CaM. In physiological processes, apo CaM, as well as (Ca2+)4‐CaM, needs to be considered a potential target of drug action.”

“Activation of RyR2 by TFP occurred in the presence or absence of CaM. TFP may also inhibit SR Ca uptake as well as increase RyR2 opening.”

“In the presence of 1 mM Ca , the increased release of PTH also was inhibited significantly by 10−4 M TFP and 10−4 M W-7.”

“The increased release of CT induced by 2.5 mM Ca was inhibited 60–90% by 10−4 M TFP and 10−4 M W-7, but was unaffected by 10−4M CLP or HAL.”

“Pre-treatment … preparations with trifluoperazine (25 μM) caused a marked reduction in the response of MEPP frequency to … stimulation (50 Hz) both in the presence of an inward electrochemical gradient for Ca2+ (50 μM Ca2+, 2 mM Mg2+) and in a Ca2+-free saline (0 Ca2+, 1 mM EGTA).”

“The presence of trifluoperazine (TFP; 50 μM), an antagonist of calmodulin, inhibited the effect of calcium (10 μM) addition in increasing NO synthase activity, indicating the existence of Ca2+/calmodulin‐dependent NO synthase in hepatoma cells.”

“ Calcium (20 microg) attenuated the antinociceptive effect of trifluoperazine and inhibited the analgesic effect of calmidazolium.”

“The Ca2+ effect was significantly inhibited by trifluoperazine (TFP; 20 or 50 microM), an antagonist of calmodulin, indicating the existence of Ca2+/calmodulin-dependent NO synthase activity in rat heart muscle cytosol.”