Atracurium besylate is a non-depolarizing, intermediate-duration, benzylisoquinolinium neuromuscular blocking agent (NMBA). It is a bis-cationic compound that acts as a competitive antagonist at the nicotinic acetylcholine receptors of the neuromuscular junction. Its unique feature is its metabolism via Hofmann elimination (a non-enzymatic, pH- and temperature-dependent process) and ester hydrolysis, making it largely independent of hepatic and renal function. It is widely used in Indian operating theatres for endotracheal intubation and as an adjunct to general anesthesia to provide skeletal muscle relaxation during surgery.
Adult: Intubation: 0.4 to 0.5 mg/kg IV bolus. Maintenance: 0.08 to 0.1 mg/kg IV bolus as required, or a continuous infusion of 0.3 to 0.6 mg/kg/hr (5-10 mcg/kg/min). Dose must be individualized based on clinical response and use of a peripheral nerve stimulator is recommended.
Note: For IV use only. Must be administered by or under the direct supervision of an anesthesiologist. Bolus dose should be given over 30-60 seconds to minimize histamine release. For continuous infusion, dilute in a compatible IV solution (e.g., 0.9% NaCl, 5% Dextrose). Do not mix with alkaline solutions (e.g., thiopentone) in the same syringe or IV line. Use a nerve stimulator to monitor depth of blockade and guide dosing.
Atracurium is a competitive antagonist at the post-synaptic nicotinic acetylcholine receptors (Nm) at the skeletal muscle neuromuscular junction. It binds to the alpha subunits of the receptor, preventing acetylcholine from binding and initiating depolarization of the motor endplate. This results in flaccid paralysis of skeletal muscles.
Pregnancy: Category C: Animal studies have shown adverse effects. Use only if clearly needed. Crosses the placenta in small amounts. May cause neonatal flaccidity if used during cesarean section. Benefits must outweigh risks.
Driving: Patients must be advised that residual muscle weakness can occur post-operatively (Postoperative Residual Curarization - PORC). They must not drive or operate machinery until full muscle strength has returned, typically several hours after the last dose.
| Inhalational Anesthetics (Isoflurane, Sevoflurane, Desflurane) | Potentiate neuromuscular blockade, reducing atracurium dose requirement by 15-50%. | Major |
| Aminoglycosides (Gentamicin, Amikacin) | Potentiate neuromuscular blockade, may cause prolonged apnea. | Major |
| Magnesium Sulfate | Potentiates neuromuscular blockade. | Major |
| Succinylcholine | Prior use may enhance the depth and duration of atracurium blockade. | Moderate |
| Calcium Channel Blockers (Verapamil) | May enhance neuromuscular blockade. | Moderate |
| Corticosteroids (chronic use) | May cause resistance to non-depolarizing NMBAs. | Moderate |
| Phenytoin, Carbamazepine | May cause resistance, requiring higher doses of atracurium. | Moderate |