Suxamethonium phenelzine

Phenelzine, a monoamine oxidase inhibitor, has been reported to cause significant prolongation of suxamethonium paralysis due to depressed plasma cholinesterase levels (to about 10% of normal). Recovery of plasma cholinesterase activity took 2 weeks (13). 

The effects of suxamethonium (succinylcholine) were enhanced in 3 patients taking phenelzine. 

Two patients, one taking phenelzine and the other who had eeased to do so 6 days previously, developed apnoea following ECT during whieh suxamethonium (succinylcholine) was used. Both responded to injeetions of nikethamide and positive pressure ventilation with oxygen. A later study observed the same response in another patient taking phenelzine. This would appear to be explained by the finding that phenelzine eaused a re-duetion in the levels of plasma cholinesterase (pseudocholinesterase) in 4... 

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