Possible Interaction: Halothane and Calcium Supplement

“There was a significant decrease in Ca level and significant increase in Mg level after treatment with halothane (p < 0.05).”

“ Halothane in concentrations exceeding 1.2 mmol litre-1 increased (P less than 0.05) the apparent intracellular concentration of calcium in lymphocytes from 12 patients being tested for susceptibility to malignant hyperthermia (MH) using the fluorescent Ca2+ indicator, fura2.”

“Chloroform (7.5 – 75 mM) and halothane (1.8 – 18 mM) were found to decrease Mg 2+ ATPase and Ca 2 + ATPase activities, whereas e0her (42.6 – 71 mM) depressed only the Mg 2+ ATPase activity.”

“Results: Halothane (5%) depressed glomus cell Ca2+i hypoxic response (mean ± SD, 94 ± 4% depression; P < 0.001 vs. control).”

“Franks JJ, Horn J-L, Janicki PK, Singh G: Halothane , isoflurane, xenon and nitrous oxide inhibit calcium ATPase pump activity in rat brain synaptic plasma membranes.”

“ Halothane also significantly inhibited release of calcium from the dense tubular system (controls, 220 ± 48 nM vs. 142 ± 31 nM [1.0 mM]).”

“ Halothane decreased the thrombin stimulated [ Calcium sup 2+]i transient and inhibited platelet aggregation in a dose-dependent manner, both in the presence and in the absence of external Calcium2+.”

“When Ca++ was omitted from the bathing medium the contractures induced in human vastus lateralis by halothane (three per cent) or succinylcholine (50 mM) were reduced by 80 and 100 per cent, respectively, while contractures induced by caffeine (8 mM) were only reduced by 50 per cent.”

“Possible explanations for this may include the drugs' combined interference with … fluxes within the myocardial and smooth muscle fibers, the ability of halothane to modify the response of … nervous system to the calcium entry blocking drugs and altered kinetics of the calcium … blocking drugs induced by the volatile anesthetic.”

“The calcium uptake in the sarcoplasmic reticulum was low after exposure of the patient to halothane.”