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Indications:
1.symptomatic control of myasthenia gravis
2.Antidote for nondepolarizing neuromuscular blocking agents
3.Urinary retention (prevention and treatment)
4.Postoperative gastrointestinal illeus.
Usual Dose:
Antimyasthenic – Intramuscular or subcutaneous.500mcg (0.5);subsequent doses should be based on the patient’s response.
Antidote (to nondepolarizing neuromuscular block) – Intravenous, 500 mcg (0.5) to 2 mg administered slowly, repeated as required up to a total dose of 5 mg.
Diagnostic aid (myasthenia gravis)1 – Intramuscular or subcutaneous, 1.5 mg administered simultaneously with 600 mcg (0.6mg) of atropine Prevention of postoperative distention or urinary retention –Intramuscular or subcutaneous, 250 mcg (0.25 mg) immediately following surgery, repeated every four to six hours for two or three days.
Treatment of postoperaitive distention –Intramuscular or subcutaneous, 500 mcg (0.5mg) as needed.
Treatment of urinary retention – Intramuscular or subcutaneous , 500 mcg (0.5mg);dose repeated every three hours for at least five doses after patient has voided or the bladder has been emptied .
Usual pediatric dose
Antimyasthenic – Intramuscular or subcutaneous, 10 to 40 mcg (0.01 to 0.04 mg )per kg of body weight every two to three hours .
Antidote ( to nondepolarizing neuromuscular block ) –Intravenous, 40 mcg (0.04 mg ) per kg of body weight administered with 20 mcg (0.02mg ) of atropine per kg of body weight .
Dignostic aid (myasthenia gravis) –Intramuscular, 40 mcg (0.04 mg) per kg of body weight or 1 mg per square meter of body surface per dose.
Intravenous, 20 mcg (0.02mg) per kg of body weight or 500 mcg (0.5 mg) per square meter of body surface.
Usual geriatric dose
See Usual adult and adolescent dose.
Mechanism Of Action:
Neostigmine inhibits destruction of acetylcholine by acetylcholine esterase, thereby facilitating transmission of impulses across the myoneural junction. It also acts on autonomic ganglion cells and neurons of CNS. It also prevents or relieves postoperative distention by stimulating gastric motility and increasing gastric tone. By prolonging the duration of action of acetylcholine at the motor end plate, It increases muscle strength in patients with myasthenia gravis.
Pharmacokinetics:
Protein binding: zero and absorb rapidly after IM injection.
Plasma half-life: 0.015-0.14 h (α – phase)
0.38-1.74 h (β- phase)
Volume of distribution by IV route: 0.53-1.56 l.kg-1
Elimination: Extrarenal and renal mechanism, following intramuscular administration, 80% of the dose is excreted in urine with 50% as unchanged drug.
Precautions and Contraindications:
- Hypersensitivity to anticholineesterase and bromides.
- Mechanical intestinal and urinary obstruction
- Peritonitis
Use with caution in patients with bronchial asthma, epilepsy, bradychardia , recent coronary occlusion, vagotonia, hyperthyroidism, cardiac arrhythmias or peptic ulcer.
FDA pregnancy category: C
Adverse Reactions:
CV: Arrhythmia (specially bradycardia) nodal rhythm, tachycardia nonspecific ECG changes; cardiac arrest; hypotension; syncope. CNS:Convulsions; dysarthria; dysphonia; dizziness; loss of consciousness; drowsiness; headache. DERM: Rash; thrombophelebite(IV use). GI:Increased salivary, gastric and intestinal secretions; nausea; vomiting; dysphagia; increased peristalsis; diarrhea; abdominal cramps; flatulence. RESP: Increased tracheobronchial secretions; laryngospasm; respiratory paralysis; dyspnea; respiratory depression; bronchospasm. OTHER: Allergy and anaphylaxis; weakness; fasciculations; muscle cramps and spasms; arthralgia; diaphoresis.
Drug Interactions:
-Drug that possess neuromuscular blocking activity, such as the aminoglycosides ,clindamycin , colistin,cyclopropane and the halogenated inhalational anesthetics may antagonise the effects of Neostigmine
-A number of drugs, including quinine,chloroquine, hydroxychloroquine , quinidine ,procainamide , propafenone , lithium and the beta blockers may reduce the effectiveness of treatment with Neostigmine .
-Prolonged bradycardia has also occurred in patients receiving beta blockers following administration of Neostigmine.
-Concomitant ophthalmic use of anticholinesterases such as ecothiopate should be undertaken with care in patients receiving Neostigmine for myasthenia gravis.
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