MIDAZOLAM IN 0.8% SODIUM CHLORIDE
Clinical safety rating: safe
No significant drug interactions Can cause hypernatremia and fluid overload.
Midazolam is a benzodiazepine that potentiates gamma-aminobutyric acid (GABA) type A receptor activity, resulting in increased chloride ion influx, neuronal hyperpolarization, and central nervous system depression.
| Metabolism | Hepatic metabolism via cytochrome P450 3A4 isoenzymes (CYP3A4) to active metabolite 1-hydroxymidazolam, followed by glucuronidation. |
| Excretion | Renal (approx. 45-57% as glucuronide conjugates; <1% unchanged); biliary/fecal (approx. 2-10%) |
| Half-life | Terminal elimination half-life: 1.8-6.4 hours (mean 3.1 h) in healthy adults; prolonged in elderly (5-6 h), obesity, hepatic impairment (up to 13 h), and critical illness (up to 20+ h). |
| Protein binding | 94-98% bound to human serum albumin. |
| Volume of Distribution | 1-3.1 L/kg (mean 1.5 L/kg); indicates extensive extravascular distribution. |
| Bioavailability | Oral: 36-44% (first-pass metabolism); IM: >90%; intranasal: ~50-83%; rectal: ~50%. |
| Onset of Action | IV: 1-3 minutes; IM: 5-15 minutes; intranasal: 5-10 minutes; oral: 15-30 minutes. |
| Duration of Action | IV: 20-60 minutes (amnesia persists 30-60 min post-administration); IM: 30-120 minutes; intranasal: 30-60 minutes. |
IV: 0.5-2 mg every 2-5 minutes as needed for procedural sedation. IM: 2-5 mg 30-60 minutes before procedure.
| Dosage form | SOLUTION |
| Renal impairment | GFR 10-50 mL/min: use with caution; consider dose reduction. GFR <10 mL/min: avoid or use extreme caution with 50% dose reduction. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: contraindicated or use with extreme caution and 75% dose reduction. |
| Pediatric use | IV: 0.05-0.1 mg/kg over 2-3 minutes; maximum total dose 6 mg. IM: 0.1-0.15 mg/kg; maximum 10 mg. |
| Geriatric use | Reduce initial dose by 50%; titrate slowly; avoid doses >1 mg IV for sedation due to increased sensitivity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Can cause hypernatremia and fluid overload.
| FDA category | Animal |
| Breastfeeding | Midazolam is excreted into breast milk in small amounts; the M/P ratio is approximately 0.63. Oral bioavailability in infants is low (30-40% due to first-pass metabolism), and adverse effects are unlikely with single doses. However, due to potential for accumulation in preterm or ill infants, caution is advised. Use lowest effective dose and monitor infant for sedation, poor feeding, or respiratory depression. |
| Teratogenic Risk |
■ FDA Black Box Warning
Risks from concomitant use with opioids; concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for patients for whom alternative treatment options are inadequate.
| Common Effects | fluid replacement |
| Serious Effects |
["Hypersensitivity to midazolam, other benzodiazepines, or any component of the formulation","Acute narrow-angle glaucoma","Severe respiratory insufficiency (e.g., COPD with hypoxemia)"]
| Precautions | ["Respiratory depression, apnea, and airway obstruction","Hypotension and cardiac dysrhythmias","Risk of seizures following rapid IV administration","Physical and psychological dependence with long-term use","Potential for abuse and misuse","Paradoxical reactions (e.g., agitation, hallucinations)","Elderly and debilitated patients are at increased risk of adverse effects","Renal or hepatic impairment may prolong drug effects"] |
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| Midazolam is a benzodiazepine classified as FDA Pregnancy Category D. First trimester exposure may be associated with a slightly increased risk of congenital malformations, particularly oral clefts, though data are conflicting. Second and third trimester use may lead to fetal benzodiazepine exposure, causing hypotonia, respiratory depression, and withdrawal symptoms (floppy infant syndrome) in neonates. Chronic use in later pregnancy may result in neonatal withdrawal. Use only if clearly needed for maternal benefit. |
| Fetal Monitoring | Monitor maternal sedation, respiratory rate, oxygen saturation, and blood pressure during and after administration. Fetal heart rate monitoring should be considered if used near delivery due to risk of fetal bradycardia and neonatal respiratory depression. In neonates, observe Apgar scores, hypotonia, and feeding ability for 24–48 hours after maternal exposure. |
| Fertility Effects | No specific data on human fertility impairment. In animal studies, midazolam did not affect fertility in rats at doses up to 10 mg/kg/day. However, benzodiazepines may alter hormonal regulation via GABA-A receptors; theoretical impact on ovulation or sperm motility is not established in humans. |