Podcast 866: Carbamazepine (Tegretol) Overdose

Contributor: Aaron Lessen MD

Educational Pearls:

What is Carbamazepine (Tegretol)?

• Carbamazepine is an anti-epileptic drug with mood-stabilizing properties that is used to treat bipolar disorder, epilepsy, and neuropathic pain.

• It functions primarily by blocking sodium channels which can prevent repetitive action potential firing.

What are the symptoms of an overdose?

• Common initial signs include diminished conscious state, nystagmus, ataxia, hyperreflexia, CNS depression, dystonia, and tachycardia

• Severe toxicity can cause seizures, respiratory depression, decreased myocardial contractility, pulmonary edema, hypotension, and dysrhythmias.

How is an overdose treated?

• An overdose is treated with large doses of activated charcoal and correction of electrolyte disturbances.

• Be ready to intubate given the potential for respiratory depression.

• Carbamazepine is moderately dialyzable and dialysis is recommended in severe overdoses.

Additional educational pearl: Individuals in correctional facilities can occasionally self-administer medications which means that medication overdose should still be on the differential for any of these individuals.

References

1. Epilepsies in children, Young People and adults: NICE guideline [NG217]. National Institute for Health and Care Excellence. (2022, April 27). https://www.nice.org.uk/guidance/ng217

2. Ghannoum M, Yates C, Galvao TF, Sowinski KM, Vo TH, Coogan A, Gosselin S, Lavergne V, Nolin TD, Hoffman RS; EXTRIP workgroup. Extracorporeal treatment for carbamazepine poisoning: systematic review and recommendations from the EXTRIP workgroup. Clin Toxicol (Phila). 2014 Dec;52(10):993-1004. doi: 10.3109/15563650.2014.973572. Epub 2014 Oct 30. PMID: 25355482; PMCID: PMC4782683.

3. Seymour JF. Carbamazepine overdose. Features of 33 cases. Drug Saf. 1993 Jan;8(1):81-8. doi: 10.2165/00002018-199308010-00010. PMID: 8471190.

4. Spiller HA. Management of carbamazepine overdose. Pediatr Emerg Care. 2001 Dec;17(6):452-6. doi: 10.1097/00006565-200112000-00015. PMID: 11753195.

5. Tran NT, Pralong D, Secrétan AD, Renaud A, Mary G, Nicholas A, Mouton E, Rubio C, Dubost C, Meach F, Bréchet-Bachmann AC, Wolff H. Access to treatment in prison: an inventory of medication preparation and distribution approaches. F1000Res. 2020 May 13;9:357. doi: 10.12688/f1000research.23640.3. PMID: 33123347; PMCID: PMC7570324.

Summarized by Jeffrey Olson, MS2 | Edited by Meg Joyce & Jorge Chalit, OMSII