Atracurium besilate

Intravenous
Endotracheal intubation, Muscle relaxant in general anaesthesia, Facilitate mechanical ventilation in intensive care
Adult: Initially, 300-600 mcg/kg as bolus inj, w/ subsequent doses of 100-200 mcg/kg by inj every 15-25 min or 5-10 mcg/kg/min by infusion in prolonged procedures. Higher infusion rate may be used in patients undergoing controlled ventilation in intensive care.
Child: >1 mth Same as adult dose.

Special Populations: Patients w/ CV disease: Initial dose should be administered over a period of at least 60 sec.

Patient w/ CV disease, burn injury, asthma; conditions which may antagonise neuromuscular blockade (e.g. resp alkalosis, hypercalcaemia, demyelinating lesions, peripheral neuropathies, denervation, muscle trauma); conditions which may potentiate neuromuscular blockade (e.g. electrolyte abnormalities, neuromuscular diseases, metabolic acidosis, resp acidosis, Eaton-Lambert syndrome, myasthenia gravis). Pregnancy and lactation. Patient Counselling May impair ability to drive or operate machinery. Monitoring Parameters Monitor heart rate, BP, resp rate; degree of muscle relaxation; renal and hepatic function when in the intensive care unit.

Skin flush, erythema, pruritus, urticaria, wheezing, increased bronchial secretions, bronchospasm, cyanosis, angioedema, CV effects (e.g. bradycardia); wheals and erythema at inj site.
Potentially Fatal: Anaphylaxis.

Symptoms: Stimulation of histamine release, CV effects esp hypotension. Management: Supportive and symptomatic treatment. Maintain adequate, patent airway w/ manual or mechanical ventilation, as necessary. May administer neostigmine, edrophonium or pyridostigmine to reverse neuromuscular blockade. If CV support is needed, treatment should include proper positioning, fluid admin and use of vasopressors as necessary.

Enhanced neuromuscular blocking effect w/ general anaesth (e.g. enflurane, isoflurane, halothane), certain antibiotics (e.g. aminoglycosides, polymyxins), lithium, Mg salts, procainamide, quinidine.

Atracurium produces neuromuscular blockade by competing w/ acetylcholine for receptors on the motor end-plate of the myoneural junction.
Onset: 2-3 min.
Duration: 15-35 min.
Distribution: Crosses the placenta (small amounts). Volume of distribution: 120-188 mL/kg. Plasma protein binding: Approx 80%.
Metabolism: Converted to laudanosine and other metabolites by degradation via Hofmann elimination; undergoes ester hydrolysis by non-specific plasma esterases.
Excretion: Via urine and bile, mostly as metabolites. Elimination half-life: Approx 20 min.

Intravenous: Store between 2-8°C. Do not freeze.

Muscle Relaxants