Carbamazepine overdose
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Reactions 1085 - 21 Jan 2006 O S Carbamazepine overdose Hyponatraemia: case report A 44-year-old woman with bipolar disorder, post-traumatic stress disorder and schizoaffective disorder developed carbamazepine-induced hyponatraemia leading to seizures after doubling her dose of carbamazepine. She had experienced a similar episode 6 months earlier after taking a large dose of carbamazepine. The woman was receiving carbamazepine 400mg in the morning and at noon and 600mg at bedtime [duration of therapy not stated]; her other medications included paroxetine and risperidone. She took double the bedtime dose of carbamazepine one evening to help her sleep and the next morning took a 200mg dose. That day, she felt faint, dizzy and lightheaded with the sensation of blood rushing to her head and also experienced narrowed vision. She then had two observed tonic-clonic seizures followed by confusion and presented at an emergency department. Investigations revealed a serum sodium level of 122 mEqL (normal 135–145) a chloride level of 85 mEq/L (98–108), a serum osmolality of 259 mOsm/kg (280–300) and a random urine sodium level of 32 mEq/L (40–200). Her serum carbamazepine concentration at this time was 11.3 µg/mL. The woman was treated with normal saline, carbamazepine was withheld and she was hospitalised. The following day, her serum sodium level had increased to 136 mEq/L and her carbamazepine concentration had decreased to 5.6 µg/mL. Carbamazepine was restarted and she was discharged. Author comment: "It is very likely that our patient was predisposed to carbamazepine-associated seizures due to her age, gender, and concurrent use of paroxetine and risperidone. We believe these factors increased her sensitivity to an acute alteration in the dose of carbamazepine." Kuz GM, et al. Carbamazepine-induced hyponatremia: assessment of risk factors. Annals of Pharmacotherapy 39: 1943-1946, No. 11, Nov 2005 - USA 801013220 1 Reactions 21 Jan 2006 No. 1085 0114-9954/10/1085-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved
Transcript of Carbamazepine overdose
Reactions 1085 - 21 Jan 2006
O SCarbamazepine overdose
Hyponatraemia: case reportA 44-year-old woman with bipolar disorder, post-traumatic
stress disorder and schizoaffective disorder developedcarbamazepine-induced hyponatraemia leading to seizuresafter doubling her dose of carbamazepine. She hadexperienced a similar episode 6 months earlier after taking alarge dose of carbamazepine.
The woman was receiving carbamazepine 400mg in themorning and at noon and 600mg at bedtime [duration oftherapy not stated]; her other medications included paroxetineand risperidone. She took double the bedtime dose ofcarbamazepine one evening to help her sleep and the nextmorning took a 200mg dose. That day, she felt faint, dizzy andlightheaded with the sensation of blood rushing to her headand also experienced narrowed vision. She then had twoobserved tonic-clonic seizures followed by confusion andpresented at an emergency department. Investigationsrevealed a serum sodium level of 122 mEqL (normal 135–145)a chloride level of 85 mEq/L (98–108), a serum osmolality of259 mOsm/kg (280–300) and a random urine sodium level of32 mEq/L (40–200). Her serum carbamazepine concentrationat this time was 11.3 µg/mL.
The woman was treated with normal saline, carbamazepinewas withheld and she was hospitalised. The following day, herserum sodium level had increased to 136 mEq/L and hercarbamazepine concentration had decreased to 5.6 µg/mL.Carbamazepine was restarted and she was discharged.
Author comment: "It is very likely that our patient waspredisposed to carbamazepine-associated seizures due to herage, gender, and concurrent use of paroxetine andrisperidone. We believe these factors increased her sensitivityto an acute alteration in the dose of carbamazepine."Kuz GM, et al. Carbamazepine-induced hyponatremia: assessment of risk factors.Annals of Pharmacotherapy 39: 1943-1946, No. 11, Nov 2005 - USA 801013220
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Reactions 21 Jan 2006 No. 10850114-9954/10/1085-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved
