A serious interaction of dantrolene and theophylline

Vet Hum Toxicol. 1990 Oct;32(5):442-3.


Dantrolene and theophylline have in common pronounced actions on several muscular systems. Therefore we investigated the interaction of these 2 drugs in rats. Normal cases of dantrolene (4 or 2 mg/kg) caused an increase in the lethality produced by theophylline, but without showing the expected seizures of theophylline toxicity. This may be caused by a synergistic action on the heart or blood vessels. On the other hand, a small dose of dantrolene decreased theophylline-induced seizures and death. This may be due to the effect of dantrolene on calcium release in skeletal muscles. The dosage of dantrolene should be decreased when used with theophylline.

MeSH terms

  • Animals
  • Dantrolene / administration & dosage
  • Dantrolene / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Drug Therapy, Combination
  • Infusions, Intravenous
  • Male
  • Mannitol / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Sodium Chloride / pharmacology
  • Theophylline / administration & dosage
  • Theophylline / pharmacology*


  • Mannitol
  • Sodium Chloride
  • Theophylline
  • Dantrolene