Dantrolene Impurities

Avoid giving Dantrolene with:

• Calcium channel blockers (e.g., Verapamil, Diltiazem) – Can cause hyperkalemia and severe cardiovascular collapse.
• CNS depressants (e.g., opioids, benzodiazepines, alcohol) – May enhance sedation and respiratory depression.
• Estrogen-containing drugs (e.g., oral contraceptives) – Increases risk of hepatotoxicity.
• Muscle relaxants (e.g., Baclofen, Cyclobenzaprine) – Risk of excessive muscle weakness.
• Warfarin – May alter its effects due to liver enzyme interactions.

• For acute malignant hyperthermia crisis:
  • Administer IV bolus of 2.5 mg/kg as quickly as possible.
  • Repeat doses up to a maximum of 10 mg/kg until symptoms resolve.
  • Prepare and administer within 10 minutes due to the urgency of the condition.
• Oral dantrolene: Typically given 1–2 times daily for chronic spasticity.

Common adverse reactions include:

• Muscle weakness – Most frequent side effect due to its muscle relaxant action.
• Drowsiness and dizziness – Due to CNS depressant effects.
• Diarrhea and nausea – Gastrointestinal upset is common with oral dantrolene.
• Photosensitivity – Increased sensitivity to sunlight.
• Hepatotoxicity (liver damage) – Especially with long-term oral use or in combination with estrogen-containing drugs.

Liver function tests (LFTs) should be monitored regularly during long-term use.

• Refrigeration is not required for Dantrolene powder for injection or oral capsules.
• Store at room temperature (20°C to 25°C / 68°F to 77°F), protected from light and moisture.
• Reconstituted IV Dantrolene should be used immediately or stored at room temperature for up to 6 hours.
• Do not freeze reconstituted solutions.