TRACRIUM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TRACRIUM (TRACRIUM).
Competitive antagonist of nicotinic acetylcholine receptors at the neuromuscular junction, preventing acetylcholine from binding and causing muscle relaxation.
| Metabolism | Hofmann elimination (non-enzymatic degradation at physiological pH and temperature) and ester hydrolysis (catalyzed by nonspecific esterases in plasma); metabolites are atracurium (laudanosine) and others. |
| Excretion | Renal (approximately 50-60% as unchanged drug and metabolites); biliary/fecal (minor, <10%); Hofmann elimination (non-enzymatic degradation) and ester hydrolysis contribute to clearance. Total excretion is predominantly renal. |
| Half-life | Terminal elimination half-life: approximately 20 minutes (range 15-30 min). Clinically, this short half-life results in rapid spontaneous recovery after discontinuation, making it suitable for continuous infusion. |
| Protein binding | Approximately 80% bound to plasma proteins, primarily albumin and gamma-globulins. |
| Volume of Distribution | 0.2-0.3 L/kg (approximately 15-20 L in adults). Indicates primarily extracellular distribution. |
| Bioavailability | Intravenous: 100% (only route of administration). Oral/IM: negligible due to rapid inactivation. |
| Onset of Action | Intravenous: 2-3 minutes for intubating doses (0.5-0.6 mg/kg). Intramuscular: not routinely used. |
| Duration of Action | Clinical duration (time to 25% recovery of twitch): 30-45 minutes after initial intubating dose. Recovery index (25-75% recovery): 10-15 minutes. Context-sensitive half-time: not applicable (short-acting). |
Initial: 0.3-0.6 mg/kg IV bolus. Maintenance: 0.1-0.2 mg/kg every 20-45 minutes as needed. Alternatively, continuous infusion: 0.005-0.01 mg/kg/min (5-10 mcg/kg/min).
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. For severe renal impairment (CrCl <30 mL/min), consider extended duration of action; monitor closely and reduce maintenance dose by 50% or extend dosing interval. |
| Liver impairment | Child-Pugh Class A: No adjustment. Child-Pugh Class B: Consider 50% reduction in initial dose and extended dosing interval. Child-Pugh Class C: Avoid use or use with extreme caution; initial dose reduction by 50-80% and titrate based on effect. |
| Pediatric use | Children (2-12 years): Initial: 0.3-0.6 mg/kg IV bolus. Maintenance: 0.1-0.2 mg/kg every 20-45 minutes. Infants (1-23 months): Initial: 0.3-0.5 mg/kg; maintenance similar to children. Neonates (<1 month): Initial: 0.25-0.4 mg/kg; extended duration expected. |
| Geriatric use | Initial dose: 0.3-0.4 mg/kg IV bolus (lower end of range). Maintenance doses should be reduced by 30-50% and dosing intervals extended due to slower clearance and prolonged duration. Monitor for prolonged neuromuscular blockade. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for TRACRIUM (TRACRIUM).
| Breastfeeding | It is not known whether atracurium is excreted in human milk. The M/P ratio is not reported. Due to its quaternary ammonium structure and high molecular weight, minimal transfer into breast milk is expected. However, caution is advised in nursing mothers because of potential adverse effects in infants. |
| Teratogenic Risk | Atracurium (TRACRIUM) is classified as FDA Pregnancy Category B. Animal reproduction studies have not shown fetal harm. There are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if clearly needed. No known teratogenic effects in first trimester; second and third trimester risks are theoretical from maternal hypoxia due to inadequate ventilation. It does not cross the placenta in significant amounts. |
■ FDA Black Box Warning
Should be administered only by experienced clinicians familiar with the use of neuromuscular blocking agents. Facilities for intubation, artificial respiration, oxygen therapy, and an antagonist must be immediately available. Use of succinylcholine is contraindicated in patients with known susceptibility to malignant hyperthermia.
| Serious Effects |
["Known hypersensitivity to atracurium or other bisbenzylisoquinolinium compounds","Patients with history of malignant hyperthermia"]
| Precautions | ["Risk of histamine release leading to hypotension and bronchospasm","Potential for neuromuscular blockade reversal before recovery","Use in elderly, renal or hepatic impairment may prolong effect","Risk of hyperkalemia in certain conditions (e.g., burns, trauma)","Monitor neuromuscular transmission regularly"] |
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| Fetal Monitoring | Monitor maternal vital signs (heart rate, blood pressure, oxygen saturation), neuromuscular transmission (train-of-four monitoring), and respiratory status. Fetal heart rate monitoring should be considered during prolonged use or in high-risk pregnancies. Assess for prolonged neuromuscular blockade in neonates if used near delivery. |
| Fertility Effects | No specific studies on fertility in humans. Animal studies have not shown impaired fertility at therapeutic doses. Atracurium is a neuromuscular blocker and does not directly affect reproductive organs or gametogenesis. |