- Presents as a colourless solution of 10mg/ml
- Dose of 0.5mg/kg provides intubating conditions in 3mins
- Variable duration of action (approx. 40mins)
Tubocurarine and Gallamine
Tubocurarine and Gallamine
- Tubocurarine is a monoquaternary alkaloid with a tertiary amine group
- It is a non-depolarising NMBA
Absorption and distribution
- pKa of 8.0
- 30-50% protein bound
- In acidic conditions:
- The tertiary amine group is protonated, which increases potency
- However plasma [K+] will also rise, altering membrane potential and offsetting the increased potency
Metabolism and excretion
- Excreted as unchanged drug in the urine (70%) and bile (30%)
- Accumulates in renal failure, though more is then excreted in the bile
Cardiovascular
- Blocks autonomic ganglion therefore no reflex tachycardia to the hypotension
Gastrointestinal
- Sialorrhoea
Adverse features
- Histamine release, which causes hypotension
- Anaphylaxis
- Gallamine is a benzylisoquinolinium NMBA
- Gallamine has a limited clinical role
- It may reduce the fasciculations caused by suxamethonium
- Selectively blocks cardiac muscarinic receptors and may cause a tachycardia
- Alkalosis prolongs its duration of action
- Excreted unchanged by kidneys and renal failure may significantly prolong its half-life