Midazolam

Midazolam In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Increases the effect of GABA on the GABA A receptor, resulting in neural inhibition, sedation, anxiolytic effects, hypnotic effects, amnesia, muscle relaxation, and anticonvulsant effects.
• It is more potent, has a shorter onset and duration of action (<1 hour in canines), and is less irritating to tissues than diazepam.

Uses of Midazolam

• Provides sedation with amnesia; as part of a premedication regime or as part of combined anaesthetic protocols.
• Emergency control of epileptic seizures (including status epilepticus).

Dose of Midazolam in Dogs and Cats

Dogs, Cats:

Emergency management of seizures including status epilepticus:

• bolus dose of 0.2–0.3 mg/kg i.v. or intrarectally if venous access is not available.
• Time to onset of clinical effect is rapid for i.v. use, therefore, repeat q10min if there is no clinical effect up to 3 times.
• Midazolam may be used in conjunction with diazepam for emergency control of seizures.
• In dogs, additional doses may be administered if appropriate supportive care facilities are available (for support of respiration).
• Once the seizures have been controlled, the dog can be maintained on a constant i.v. infusion of 0.3 mg/kg/h.

Side Effects of Midazolam in Dogs and Cats

• In human patients, i.v. administration of midazolam has been associated with respiratory depression and severe hypotension.
• Excitement may occasionally develop.

Contraindications of Midazolam in Dogs and Cats

• Avoid in neonates.

Some Notes:

• Midazolam potentiates the effect of some anaesthetic agents, reducing the dose required, including propofol and some inhalation agents.
• Concurrent use of midazolam with NSAIDs (in particular diclofenac), antihistamines, barbiturates, opioid analgesics or CNS depressants may enhance the sedative effect.
• Opioid analgesics may increase the hypnotic and hypotensive effects of midazolam.
• Erythromycin inhibits the metabolism of midazolam.
• It is often used with ketamine to offset the muscle hypertonicity caused by the ketamine.
• If used at induction, it may reduce the propofol requirement.
• Midazolam can be diluted with saline, but avoid fluids containing calcium as this may result in precipitation of midazolam.
• Use with caution in severe hypotension, cardiac disease and respiratory disease.
• As it is metabolized by the cytochrome P450 enzyme system care should be taken in animals with hepatic impairment.