midazolam: clinical use

Prescribing considerations

• Administer only where trained staff, respiratory and cardiovascular monitoring, oxygen and resuscitation facilities are available.
• Use caution in older, debilitated or critically ill patients and in respiratory, renal, hepatic or cardiac impairment.
• Review opioids, other sedatives and CYP3A4 inhibitors or inducers before administration.
• Prolonged intensive-care use can cause tolerance, physical dependence and withdrawal; avoid abrupt cessation after sustained exposure.
• Paradoxical agitation and aggression occur more often in children and older people.

Contraindications and cautions

• Hypersensitivity to midazolam, another benzodiazepine or a formulation excipient.
• For the selected injection, conscious sedation in severe respiratory failure or acute respiratory depression.
• For the selected oral solution: severe hepatic impairment, severe respiratory failure or acute respiratory depression, myasthenia gravis, sleep apnoea, and anatomical respiratory impairment or lung disease.
• The selected oral solution is not licensed for children younger than 6 months.

Monitoring

• Assess respiratory rate, oxygen saturation, airway patency, consciousness and cardiovascular status according to the setting.
• Continue observation through recovery because respiratory depression may appear after procedural stimulation ends.
• Monitor longer where elimination may be delayed, other depressants were used, or flumazenil has been administered.
• Ensure discharge criteria are met and an appropriate escort is available.

Clinical pharmacology

A short-acting imidazobenzodiazepine that enhances GABA-mediated inhibition. It is metabolised mainly through CYP3A4 to an active hydroxylated metabolite; hepatic impairment, low cardiac output, critical illness and prolonged exposure can delay recovery.

Formulation and product differences

• The selected oral solution is swallowed and licensed for procedural sedation or anaesthetic premedication in children aged 6 months to 14 years.
• The oral formulation has more pronounced CYP3A4 interactions because intestinal and hepatic metabolism affect exposure.
• The selected injection may be given intravenously or intramuscularly by trained clinicians and supports procedural, anaesthetic and intensive-care indications.
• The formulations are not interchangeable with buccal or oromucosal seizure products; check route and product instructions carefully.

Oral solution

Route: Oral

Strengths: 5 mg/mL

Injection

Route: Parenteral

Strengths: 5 mg/1 mL