Guanethidine monosulphate

Treatment of hypertensive crisis

Potentially hazardous interactions with other drugs
Anaesthetics: enhanced hypotensive effect.
Sympathomimetics: hypotensive effect antagonised by dexamfetamine, ephedrine, isometheptene, lisdexamfetamine, metaraminol, methylphenidate, noradrenaline, oxymetazoline, phenylephrine, phenylpropanolamine, pseudoephedrine and xylometazoline.

Guanethidine is partially metabolised in the liver, and is excreted in the urine as metabolites and unchanged guanethidine.