Muscle relaxants should be administered only after induction of anaesthesia and when a secure airway has been established. The dosage must be adjusted according to the response. As a guide: Adults: 1-1.5 mg/kg i.v. initially, then 0.5-1 mg/kg as required at about 40-minute intervals. Children: 1.5 mg/kg initially, then 0.5 mg/kg as required. Infants of less than 1 month: 250-750 micrograms/kg initially, then 100-500 micrograms/kg as required.

The mechanisms of action of gallamine on nerve terminals, cholinergic receptors, and the threshold for propagation of end-plate potentials to the muscle fiber were investigated in rat phrenic nerve-diaphragm preparations. Intracellular studies were made with glass microelectrodes to determine changes in end-plate potentials and miniature end-plate potentials produced by gallamine at concentrations between 0.1 uM to 100 uM.