Features:
(1) worsening of a seizure disorder while the patient is being treated with an antiepileptic drug
(2) exacerbation of the seizure as the dose of the seizure medication is increased
(3) improvement on reducing or discontinuing the drug
(4) exclusion of other causes (drug abuse, nonadherence, etc)
where:
• Therapeutic drug monitoring may be helpful to confirm the presence of the drug at the expected concentration. It can also help to identify excessive dosing.
• Identifying the causative medication can be challenging if the person is on several antiepileptic medications.
Drugs that have been reported to cause paradoxical worsening of seizures:
(1) phenytoin
(2) vigabatrin
(3) benzodiazepines
(4) valproic acid
(5) carbamazepine
(6) gabapentin
Possible explanations:
(1) incorrect diagnosis of the seizure type
(2) use of a drug that is contraindicated in a specific type of seizure disorder
(3) toxicity due to excessive dosing of the antiepileptic drug
(4) toxicity due to the use of several drugs in combination (polypharmacy)
