Ten patients with severe, therapy-resistant manic agitation received magnesium sulphate infusions with a continuous magnesium (Mg) flow of approximately 200 mg/h (4353+/-836 mg/day; daily monitored Mg plasma level: 2.44+/-0.34 mmol/l) for periods ranging from 7 to 23 days. Concomitant psychotropic treatment consisted of lithium (n = 10), haloperidol (n = 5) and clonazepam (n = 10). During i.v. Mg treatment the mean values of the maximum dosages of neuroleptics (in chlorpromazine equivalents) and benzodiazepines (in diazepam equivalents) were significantly lower than during the last day of pretreatment (= baseline). Seven patients showed a marked improvement in the Clinical Global Impression scale. In case of bradycardia detected by the ECG monitor (n = 5), Mg flow was reduced and bradycardia disappeared promptly. Mg i.v. may be a useful supplementary therapy for the clinical management of severe manic agitation. This open study needs double-blind confirmation.

Heiden A, Frey R, Presslich O, Blasbichler T, Smetana R, Kasper S
Psychiatry Res 1999 Dec;89(3):239-46
PMID: 10708270