Stigmin

G-G-Neostigmine is indicated for-
The symptomatic control of myasthenia gravis when oral therapy is impractical.
The prevention and treatment of postoperative distention and urinary retention after mechanical obstruction has been excluded.
Reversal of effects of nondepolarizing neuromuscular blocking agents (e.g., Tubocurarine, metocurine, gallamine or pancuronium) after surgery.

Antagonist to Nondepolarising Neuromuscular Blockade:
Adults
: A single dose of Neostigmine Methylsulfate injection 2 to 3 mg with atropine sulphate 0.6-1.2 mg by slow IV injection over 1 minute. The recommended ratio of atropine to Neostigmine Methylsulfate injection is 1:2 to 1:3. The maximum recommended dose of Neostigmine Methylsulfate injection in adults is 5 mg.
Children
: The suggested dose in children is 0.05 mg/kg/dose and atropine sulphate 0.02 mg/kg/dose by slow IV injection. Maximum recommended dose of Neostigmine Methylsulfate injection in children is 2.5 mg.
Myasthenia Gravis:
Adults
: 1 mg to 2.5 mg given IM or SC at intervals throughout the day when greater strength may be needed (e.g. mornings and before meals), given a total daily dose of 5 to 20 mg. Duration of action of a single dose is 2 to 4 hours.
Neonates
: 0.05-0.25 mg IM every 2-4 hours, half an hour before feeding. Treatment is not usually required beyond 8 weeks of age. Because the condition is usually self limiting the daily dosage should gradually be reduced until the medicine can be withdrawn.
When large doses of Neostigmine Methylsulfate injection are given to myasthenic patients, atropine sulphate may be required to counteract the muscarinic side effects.
Urinary Retention:
Prophylaxis
: 0.25 mg SC or IM before or immediately after the operation, repeated every 4 to 6 hours for 2-3 days.
Treatment
: 0.5 mg SC or IM and apply warmth to lower abdomen. After patient has voided continue 0.5 mg SC or IM every 3 hours for at least 5 injections. If there has been no urinary response within one hour of the first dose, the patient should be catheterised.

Adverse reactions generally associated with G-Neostigmine overdosage are:
Cardiovascular
: Cardiac arrhythmias (especially bradycardia), hypotension, cardiac arrest, syncope.
Central Nervous System
: Headache, dizziness, convulsions, loss of consciousness, coma, drowsiness, restlessness, ataxia, slurred speech, agitation and fear.
Gastrointestinal
: Nausea, vomiting, diarrhoea, flatulence, abdominal cramps, increased peristalsis and involuntary defaecation.
Genitourinary
: Involuntary urination or desire to urinate.
Musculoskeletal
: Muscle cramps, fasciculation, general weakness and paralysis. Respiratory: Increased oral, pharyngeal and bronchial secretion, dyspnoea, bronchospasm, respiratory depression, respiratory failure, tight chest and wheezing.
Allergic
: Allergic reactions including anaphylaxis.
Skin
: Rash and urticaria. Others: Increased sweating and salivation, miosis, vision changes, nystagmus and lacrimation.

G-Neostigmine Methylsulfate should be used with caution in patients with epilepsy, bronchial asthma, bradycardia, recent coronary occlusion, vagotonia, hyperthyroidism, cardiac arrhythmias or peptic ulcer. When large doses of G-Neostigmine Methylsulfate are administered, the prior or simultaneous injection of atropine sulfate may be advisable. Separate syringes should be used for the G-Neostigmine Methylsulfate and atropine. Because of the possibility of hypersensitivity in an occasional patient, atropine and antishock medication should always be readily available.

Neostigmine Methylsulfate Injection, an anticholinesterase agent is a sterile, nonpyrogenic solution of Neostigmine Methylsulfate in Water for Injections intended for intramuscular (IM), intravenous (IV) or subcutaneous (SC) administration.
Neostigmine is a parasympathomimetic, specifically, a reversible cholinesterase inhibitor. The drug inhibits acetylcholinesterase which is responsible for the degredation of acetylcholine. So, with acetylcholinesterase inhibited, more acetylcholine is present By interfering with the breakdown of acetylcholine, neostigmine indirectly stimulates both nicotinic and muscarinic receptors which are involved in muscle contraction.. It does not cross the blood-brain barrier.