Hypermagnesemia. A potential complication during treatment of theophylline intoxication with oral activated charcoal and magnesium-containing cathartics.

Toxic reaction to theophylline compounds is common. Oral activated charcoal (OAC) is a widely accepted mode of therapy for management of moderate to severe cases of theophylline toxicity. Magnesium-containing cathartics are generally recommended in conjunction with OAC in the treatment of drug or toxin ingestions. We report two cases of hypermagnesemia complicating the treatment of theophylline toxicity with OAC and magnesium citrate. In both patients, the hypermagnesemia contributed significantly to morbidity or mortality. In light of these cases and after review of the literature, we suggest that sorbitol be considered the cathartic agent of choice in the treatment of theophylline toxicity with OAC.