NEOSTIGMINE

“PROSTIGMINE”

1) Action

• Antagonist to cholinesterase — potentiates naturally occurring Ach

• [the natural enzyme which destroys Ach]

2) Mechanism

• Allows accumulation of Ach at endplates hence displaces relaxant from receptor site

3) Indications

• Antidote to non-depolarising muscle relaxants

• Urinary retention; Myasthenia gravis

4) Effects on organs—side effects

• Muscarinic effects: nausea, vomiting diarrhoea, abdominal cramps, increased bronchial secretions

• Nicotinic effects: muscle cramps, fasciculation, weakness

5) Toxic effects/ precautions with administration

• Atropine should be given 10-15 minutes prior to neostigmine to counteract the muscarinic side effects

6) Contraindications

7) Reversal, antagonism or antidote

8) Loading dose, maintenance dose, frequency & method of administration

• 2.5 mg/ml [1ml]

• 1-5 mg IV as antidote to curariform drugs

9) Drug’s metabolism—Drug’s excretion—Half life (pharmacokinetics)

• Elimination half life: 80 min

10) Important drug interactions

• May be potentiated, slowed down or blocked by a large variety of drugs