Cardiac side effects of phenytoin and carbamazepine. A dose-related phenomenon?

Abstract

Three patients with dystrophia myotonica and echocardiographic signs of subclinical cardiopathy had cardiac side effects during oral treatment with phenytoin sodium or carbamazepine. These side effects were dose related: ventricular tachycardia appeared at a toxic serum phenytoin level in one patient and disappeared as the concentration fell within the therapeutic range, and atrioventricular block grade 1 developed in two patients at low serum carbamazepine levels, its severity increasing with the drug level. Given the risk of dangerous side effects, cardiac status needs to be carefully assessed before administration of phenytoin or carbamazepine in the treatment of dystrophia myotonica.

• Authors: L Durelli, R Mutani, G P Sechi, F Monaco, N Glorioso, G Gusmaroli
• Journal: Archives of neurology (Arch Neurol) Vol. 42 Issue 11 Pg. 1067-8 (Nov 1985) ISSN: 0003-9942 [Print] United States
• PMID: 4051836 (Publication Type: Case Reports, Journal Article)

Chemical References

• Carbamazepine
• Phenytoin

Topics

• Adult
• Carbamazepine (adverse effects, blood, therapeutic use)
• Female
• Heart Block (chemically induced)
• Humans
• Male
• Middle Aged
• Phenytoin (adverse effects, blood, therapeutic use)
• Tachycardia (chemically induced)