Possible Interaction: Caffeine and Halothane

“Strong pharmacological synergism between CAF and HAL is demonstrated in both single-channel and myotube preparations.”

“Anesth Analg 1983;62:545-52) presents intriguing support for their thesis that muscle contracture responses to the combined use of halothane and caffeine define an intermediate group of susceptibility to malignant hyperthermia (MH).”

“We (10) and other investigators (11) also have observed this broad range of response in normal people when their muscle specimen is exposed to the combination of halothane 2nd caffeine and have concluded that that portion of the muscle biopsy test lacks precision.”

“In vifro muscle contracture test responses, which are positive only during combined halothane plus caffeine testing , may represent an intermediate response.”

“We present four cases in which the proband (the first individual within a family presenting with possible signs of MH) exhibited positive responses only to combined halothane plus caffeine during in vifru testing.”

“The "K-type" designation is used to describe a patient being investigated for malignant hyperthermia (MH) when concurrent administration of caffeine and halothane induces muscle contracture (rigidity, spasm) in vitro, but when halothane and caffeine given separately produce a normal response.”

“The measured parameters that were utilized for the current study were contractures induced in vitro by caffeine or by caffeine plus halothane.”

“Aggregation induced by halothane could be potentiated by small doses of adrenaline or ADP and in some individuals by caffeine.”

“Out of 22 patients being possibly MH susceptible [9] or having survived an anaesthetic complication [13] 4 showed decreased caffeine thresholds and increased contractures to caffeine plus halothane which is in accordance with MH susceptibility.”

“In the presence of 0.4% halothane, caffeine contractures were greater but the magnitude of halothane potentiation decreased as the caffeine concentration was increased.”

“li]4.|Muscle specimens which in the presence of halothane required more than 1.3 millimolar concentration of caffeine to produce a tension increase of 1 gram were defined as controls.”

“The caffeine contracture of normal human muscle, which has been used as a model for malignant hyperpyrexia, is greatly potentiated by halothane.”