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Published on: November 8, 2018
Carbamazepine-induced hyperammonemia
Erin N Adams1, Alla Marks, Mitsi H Lizer
1Bernard J. Dunn School of Pharmacy, Shenandoah University, 1775 North Sector Court, Winchester, VA 22601, USA. eadams@su.edu
Summary
Carbamazepine, a medication for bipolar disorder, can cause hyperammonemia, a condition of high ammonia levels in the blood. This case highlights the importance of monitoring ammonia levels during carbamazepine treatment.
Area of Science:
- Neuroscience
- Clinical Pharmacology
- Toxicology
Background:
- Carbamazepine is a widely used antiepileptic and mood-stabilizing drug.
- Hyperammonemia is a potentially serious condition characterized by elevated ammonia levels in the blood.
- Patients with bipolar disorder often require long-term medication management.
Observation:
- A 26-year-old male with bipolar disorder and seizure disorder developed severe agitation and aggressive behavior.
- The patient had recently started carbamazepine therapy for aggression and seizure control.
- Elevated serum ammonia levels (127 microg/dL) were detected, with therapeutic carbamazepine levels (3.9 microg/mL).
Findings:
- Carbamazepine discontinuation led to the normalization of serum ammonia levels within four days.
- The patient had a history of elevated ammonia levels with valproic acid and a previous episode with carbamazepine.
- This suggests a potential idiosyncratic reaction to carbamazepine causing hyperammonemia.
Implications:
- Clinicians should consider monitoring ammonia levels in patients exhibiting unexplained neurological or behavioral changes during carbamazepine therapy.
- This case underscores the importance of a thorough medication history, including previous adverse drug reactions.
- Further research may be warranted to elucidate the mechanism of carbamazepine-induced hyperammonemia.
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