Carbamazepine toxicity following Oxybutynin and Dantrolene administration: a case report.
OBJECTIVE
To report a case of Carbamazepine toxicity following the administration of Oxybutynin and Dantrolene.


METHODS
A case report.


METHODS
The Spinal Rehabilitation Department, Loewenstein Hospital, Raanana, Israel.


METHODS
A patient with C6D tetraplegia who sustained intoxication because of drug interaction is presented. She had been treated by Carbamazepine 1000 mg/day for neuropathic pain for 2 years without clinical or laboratory signs of toxicity. After administration of Oxybutynin concomitantly with an increase in the dose of Dantrolene, she presented the clinical symptoms and laboratory finding of Carbamazepine intoxication. Trying to adjust the treatment to the patient's requirements, Carbamazepine together with Oxybutynin and Dantrolene was readministrated in lower doses.


RESULTS
The combination of these drugs, even small doses, caused toxicity. Adding Dantrolene and Oxybutynin elevated the blood level of Carbamazepine, possibly by inhibition of cytochrome P450.


CONCLUSIONS
A possible pharmacokinetic interaction between Dantrolene and Oxybutynin should be borne in mind when considering Carbamazepine medication for a patient with a spinal cord lesion.
Vander
T
T
Department of Spinal Rehabilitation, Loewenstein Rehabilitation Hospital, Raanana, Israel.
Odi
H
H
Bluvstein
V
V
Ronen
J
J
Catz
A
A
D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects*; D002220:Carbamazepine / Q000009:adverse effects*; D003620:Dantrolene / Q000008:administration & dosage*; D004244:Dizziness / Q000139:chemically induced*; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008333:Mandelic Acids / Q000008:administration & dosage*; D009125:Muscle Relaxants, Central / Q000008:administration & dosage; D009437:Neuralgia / Q000188:drug therapy / Q000209:etiology; D011782:Quadriplegia / Q000150:complications; D014839:Vomiting / Q000139:chemically induced
D018712:Analgesics, Non-Narcotic; D008333:Mandelic Acids; D009125:Muscle Relaxants, Central; D002220:Carbamazepine; D003620:Dantrolene; C005419:oxybutynin