Progressive muscle weakness with respiratory insufficiency in a young patient with tetanus during magnesium sulfate infusion.

Magnesium sulfate administered as an intravenous infusion is considered safe. However, there have been concerns about the neuromuscular blocking properties of magnesium that can cause respiratory insufficiency. We report a patient with mild tetanus who, after being started on magnesium infusion, developed progressive respiratory insufficiency, proximal muscle weakness and ptosis. On discontinuation of magnesium infusion, the muscular weakness improved and respiration became normal. The safety of magnesium sulfate infusion for the management of tetanus needs to be re-evaluated.