Drug Guide
Midazolam
Classification
Therapeutic: Sedative, Anxiolytic, Amnesic, Hypnotic, Sedative-Hypnotic
Pharmacological: Benzodiazepine
FDA Approved Indications
- Acute treatment of intermittent, stereotypic episodes of partial seizures with or without generalization in patients aged 12 years and older.
Mechanism of Action
Midazolam enhances the effect of gamma-aminobutyric acid (GABA) at the GABA-A receptor, resulting in sedative, anxiolytic, amnesic, anticonvulsant, and muscle-relaxant properties.
Dosage and Administration
Adult: For seizures, the typical dose is 2.5 mg administered intranasally. Doses may be repeated after 10 minutes if seizures persist. Maximum dose per episode is 5 mg.
Pediatric: Dosing varies by weight and age; typically 0.2 mg/kg (up to 5 mg) intranasally or buccally, repeated after 10 minutes if needed.
Geriatric: Lower initial doses due to increased sensitivity; close monitoring recommended.
Renal Impairment: Use with caution; dose adjustments not well established.
Hepatic Impairment: Use with caution; may prolong sedation.
Pharmacokinetics
Absorption: Rapid via intranasal or buccal routes.
Distribution: Widely distributed, crosses blood-brain barrier.
Metabolism: Hepatic CYP3A4 metabolism.
Excretion: Metabolites excreted primarily in urine.
Half Life: Approximately 2 hours in healthy adults, may be prolonged in certain populations.
Contraindications
- Hypersensitivity to midazolam or benzodiazepines.
- Severe respiratory insufficiency.
- Sleep apnea syndrome.
- Acute narrow-angle glaucoma.
Precautions
- Use with caution in elderly, debilitated, or patients with compromised respiratory or hepatic function.
- Risk of respiratory depression, especially when combined with other CNS depressants.
Adverse Reactions - Common
- Drowsiness (Common)
- Dizziness (Common)
- Respiratory depression (Uncommon)
Adverse Reactions - Serious
- Respiratory arrest (Rare)
- Hypotension (Uncommon)
- Prolonged sedation (Uncommon)
Drug-Drug Interactions
- CNS depressants (opioids, alcohol)
- Other benzodiazepines
- Cimetidine (may increase plasma levels)
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor respiratory status (rate, depth), sedation level, and blood pressure.
Diagnoses:
- Risk for respiratory depression
- Impaired spontaneous ventilation
Implementation: Administer in healthcare setting with resuscitation equipment available. Adjust dosing based on patient response.
Evaluation: Ensure patient remains stable with adequate airway and breathing; assess for adverse reactions.
Patient/Family Teaching
- Do not operate heavy machinery or drive after administration.
- Report excessive sedation, difficulty breathing, or other concerning symptoms.
- Inform about the potential for drowsiness and impairment.
Special Considerations
Black Box Warnings:
- Respiratory depression and respiratory arrest
Genetic Factors: CYP3A4 polymorphisms may affect metabolism.
Lab Test Interference: None.
Overdose Management
Signs/Symptoms: Extreme drowsiness, respiratory depression, hypotension, coma.
Treatment: Supportive care, maintain airway, oxygen, IV fluids, and ventilatory support if needed. Flumazenil as an antagonist may be considered, with caution.
Storage and Handling
Storage: Store at room temperature, protected from light and moisture.
Stability: Stable under recommended storage conditions.