(1989; 60 pages) [French]
Group: cholinesterase inhibitor
Injection: 0.5, 2.5 mg (metilsulfate)/ml in 1-ml ampoule
Neostigmine is a cholinesterase inhibitor that raises the concentration of acetylcholine at the myoneural junction and other cholinergic nerve endings. Administered parenterally, the effect of a single dose persists for 2-4 hours. It is destroyed by plasma esterases and excreted in the urine.
• To counteract the effect of non-depolarizing muscle relaxants administered during surgery.
• Treatment of postoperative non-obstructive urinary retention.
Reversal of muscle relaxation
Adults: 2.5 mg by i.v. injection. Supplements of 0.5 mg may be administered as necessary up to a maximum of 5 mg. Atropine sulfate (600-1200 micrograms i.v.) administered immediately beforehand prevents autonomic excitation.
Children: 40 micrograms/kg i.v. after atropine sulfate (20 micrograms/kg i.v.) administered as above.
Titration of the required dose using a peripheral-nerve stimulator is advisable in small children and severely ill patients.
The initial dose should be reduced in patients with bronchial asthma, postoperative atelectasis, bradycardia, atrioventricular block and other cardiac dysrhythmias, epilepsy and parkinsonism.
Postoperative non-obstructive urinary retention
Adults: 500 micrograms i.m. or subcutaneously initially, repeated every 3 hours for at least 15 hours once the patient has voided the bladder. If urine is not passed within 1 hour of the initial dose the patient’s bladder should be catheterized. Cystoscopy is indicated if retention persists.
• Hypersensitivity to neostigmine.
• Mechanical obstruction of the intestinal or urinary tracts.
Equipment for resuscitation and mechanically assisted respiration should be immediately available.
Neostigmine should be given only after halothane or ether administration has been discontinued.
Adequate ventilation must be maintained since respiratory acidosis predisposes the patient to cardiac dysrhythmias.
Use in pregnancy
Neostigmine should be administered only when the need outweighs any possible risk to the fetus. Premature labour has been induced following intravenous administration near term.
Neostigmine may produce signs of excessive cholinergic activity, including nausea and vomiting, increased salivation, diarrhoea, abdominal cramps, cardiac dysrhythmias, syncope and hypotension.
Rash, urticaria and anaphylaxis have been reported.
Neostigmine potentiates the effect of depolarizing muscle relaxants. It should therefore not be used in conjunction with suxamethonium.
Sudden death may occur as a result of cardiac arrest. More frequently a “cholinergic crisis” is induced, characterized by nausea, vomiting, diarrhoea, excess salivation and rapidly progressive paralysis. Ventilation must be mechanically assisted until spontaneous breathing returns. Atropine (1 mg i.v.) serves to block the autonomic effects.
Neostigmine should be stored in ampoules protected from light, and should not be allowed to freeze.