| Atracurium Pharmacology |
| Atracurium |
| About Atracurium |
| Nondepolarizing Neuromuscular Blocker Agent, Peripherally acting Skeletal muscle relaxant, adjunct to general anesthesia. |
| Mechanism of Action of Atracurium |
| This neuromuscular blocking agent antagonizes the neurotransmitter action of acetylcholine by binding competitively with cholinergic receptor sites on the motor end-plate and blocks the transmission through it. This results the depolarization which leads to desensitization and reduce the skeletal muscle tone. It can also release the histamine in the body. General anaesthesia: It is often administered during the induction of anaesthesia to relax muscles of the jaw, neck and airway and thereby facilitate laryngoscopy and endotracheal intubation. Following induction, continued muscle relaxation is required for many procedures to aid surgical exposure and to provide additional insurance of immobility. |
| Pharmacokinets of Atracurium |
| Absorption- Rapidly and completely absorbed after intravenous administration Distribution- Widely distributed into the extra cellular space. 82% bound to the plasma proteins Metabolism- Metabolized in plasma by Hoffman degradation and ester hydrolysis Excretion- Excreted through urine and feces |
| Onset of Action for Atracurium |
| 2 minutes after administration |
| Duration of Action for Atracurium |
| 35 to 70 minutes |
| Half Life of Atracurium |
| Its plasma half life is 17-21 minutes |
| Side Effects of Atracurium |
| 1. Allergic reactions. 2. Inadequate or prolonged block. 3. Hypotension vasodilatation. 4. Bradycardia. 5. Tachycardia. 6. Dyspnoea. 7. Broncho-laryngospasm. 8. Rash. 9. Urticaria. 10. Reaction at the injection site. |
| Contra-indications of Atracurium |
| Contraindicated in patients who are hypersensitive to it |
| Special Precautions while taking Atracurium |
| 1. Cardiovascular disease. 2. Asthma. 3. Electrolyte imbalance. 4. Myasthenia gravis. 5. Long term infusion. |
| Pregnancy Related Information |
| Use with caution |
| Old Age Related Information |
| Use with caution |
| Breast Feeding Related Information |
| Use with caution |
| Children Related Information |
| Use with caution |
| Indications for Atracurium |
| As an adjunct to general anesthesia, to facilitate endotracheal Intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation |
| Interactions for Atracurium |
| Thiazide diuretics: Cause hypokalaemia which enhances the neuromuscular blockade. Enflurane, Isoflurane, Halothane, Aminoglycosides, Polypeptide antibiotics (bacitracin, capreomycin, colistimethate, polymyxin B) Clindamycin, Linomycin, Lithium, Verapamil, Trimethaphan, Procainamide & Quinidine: Enhance the neuromuscular blockade. Magnesium Salts: Reversal of neuromuscular blockade unsatisfactory therefore dose of Atracurium besylate should be lowered. Other muscular relaxants: May have both synergistic and antagonist effect. Phenytoin & Theophylline: Resistance to or reversal of neuromuscular blockade of atracurium. Succinylcholine: Enhances atracurium induced neuromuscular blockade. |
| Typical Dosage for Atracurium |
| Intravenous- Adult- For muscle relaxation in surgical anesthesia- Induction – 0.3-0.6 mg/kg body wt. i.v Maintenance – 0.1-0.2 mg body wt. /hour by continuous i.v. infusion. Premature neonates: 0.3 mg/kg. |
| Schedule of Atracurium |
| H |
| Storage Requirements for Atracurium |
| Store at 2 – 8 degree C (36 and 46 degrees F). Do not freeze. |
| Effects of Missed Dosage of Atracurium |
| Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose. |
| Effects of Overdose of Atracurium |
| Give symptomatic and supportive treatment. Reversal of blockade may be accomplished by administering an anticholinesterase agent (edrophomium, physostigmine, or neostigmine) with an anticholinergic agent (atropine or glycopyrrolate). |