MIDAZOLAM IN 0.8% SODIUM CHLORIDE
Clinical safety rating
safeNo 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. |
| Molecular Weight | 325.77 |
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 | Avoid unless clearly needed; may cause congenital malformations (limited data). |
| 2nd trimester | Use only if potential benefit justifies risk; may cause fetal CNS depression. |
| 3rd trimester | Avoid near term; risk of neonatal withdrawal, respiratory depression, and hypotonia. |
Clinical note
No significant drug interactions Can cause hypernatremia and fluid overload.
| FDA category | Animal |
| Placental transfer | Midazolam readily crosses the placenta; fetal concentrations similar to maternal. |
| Breastfeeding | Midazolam is excreted into breast milk in low amounts; use with caution, monitor for sedation and feeding difficulties in infant. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | 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. |
■ 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 |
Acute narrow-angle glaucomaKnown hypersensitivity to benzodiazepinesSevere respiratory insufficiencyMyasthenia gravisSleep apnea syndrome
| 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 |
| Food/Dietary | Avoid grapefruit juice as it may increase midazolam levels. No other significant food interactions. |
| Clinical Pearls | Midazolam in 0.8% sodium chloride is an isotonic solution suitable for IV/IM use. Rapid onset (1-2 min IV); watch for respiratory depression, especially with opioids. Flumazenil is reversal agent. Prolonged sedation in elderly, hepatic impairment, or obesity. Avoid intra-arterial injection. Compatible with D5W, LR; do not mix with alkaline solutions. |
| Patient Advice | This medication will cause drowsiness and amnesia; do not drive or operate machinery for at least 24 hours after use. · Avoid alcohol and other sedatives for 24 hours after receiving this medication. · Inform your healthcare provider if you have a history of glaucoma, lung disease, or kidney/liver problems. · You may not remember events that occur after administration; arrange for someone to accompany you home. · Breathing problems are possible; seek immediate medical help if you have difficulty breathing. |
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