Causative Agents

The significance of a pyrexia has to be considered in the context of each case (including clinical environment e.g. resuscitation area following anaesthetic induction) and after a history and especially drug history has been taken. In addition to a prescribed drug history, it is important to take a history of recreational drug use and assess risk of any overdose. In addition, non-drug causes for hyperthermia should always be considered including sepsis.

Below are listed the causative drugs for each hyperthermic syndrome:

Malignant hyperthermia

  • Anaesthetic gases eg halothane, isoflurane, cyclopropane
  • Depolarising neuromuscular relaxants e.g. suxamethonium

Neuroleptic malignant syndrome

  • Typical antipsychotics e.g. chlorpromazine, haloperidol, prochlorperazine
  • Atypical antipschotics e.g. olanzapine, clozapine, quetiapine
  • Tricyclic antidepressants e.g. amitriptyline, clomipramine, imipramine
  • Monoamine oxidase inhibitors e.g. phenelzine, moclobemide
  • Anticonvulsants
  • Withdrawal or dose reduction of antiparkinsonian medications such as Levodopa or other dopamine agonists

Anticholinergic poisoning

  • Antihistamines e.g. chlorphenamine, cyproheptadine, hydroxyzine, promethiazine
  • Neuroleptics e.g. chlorpromazine, olanzapine, quetiapine
  • Antiparkinsonian drugs e.g. trihexyphenidyl, benztropine
  • Antispasmodics e.g. hyoscyamine, oxybutynin, propantheline
  • Tricyclic antidepressants e.g. amitriptyline, clomipramine, imipramine
  • Atropine
  • Cyclopentolate

Sympathomimetic poisoning

  • Cocaine
  • Ecstasy (MDMA)
  • Metamphetamines
  • Amphetamines

Serotonin syndrome

  • Amphetamines
  • Cocaine
  • Ecstasy(MDMA)
  • Tramadol
  • Levodopa
  • Lithium
  • SSRIs e.g. citalopram, fluoxetine, sertraline
  • SNRIs e.g. venlafaxine
  • Serotonin modulators e.g. trazadone
  • Tricyclic antidepressants e.g. amitriptyline, clomipramine, imipramine
  • Metoclopramide
  • Ondansetron
  • Dextrometorphan
  • Monoamine oxidase inhibitors e.g. phenelzine, moclobemide
  • LSD

Other drugs causing hyperthermia

  • Salicylate
  • Strychnine