Methsuximide Disease Interactions

Hematologic toxicities, some with fatal outcome, have been associated with the use of succinimide anticonvulsants. Leukopenia, agranulocytosis, aplastic anemia, thrombocytopenia, pancytopenia, and eosinophilia have been reported. Therapy with succinimide anticonvulsants should be administered cautiously in patients with preexisting blood dyscrasias and/or bone marrow suppression. Complete blood counts, including platelets, should be performed prior to initiating therapy and periodically during therapy. Marked depression of blood counts may be indication for withdrawal of succinimide therapy.

Succinimide anticonvulsants have produced morphological and functional changes in the liver of animals. In humans, abnormalities in liver and renal function studies have been reported. Therapy with succinimide anticonvulsants should be administered with extreme caution in patients with known hepatic or renal diseases. Periodic urinalysis and liver function tests are recommended for all patients treated with these drugs.

Cases of systemic lupus erythematosus (SLE) have been reported in association with the use of succinimide anticonvulsants, primarily ethosuximide. Some of the patients recovered promptly following discontinuation of the drug, while others continued to have active disease long after. Therapy with succinimide anticonvulsants should be administered cautiously in patients with a history of SLE.

Antiepileptic drugs (AEDs) have been associated with an increased risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Pooled analyses of 199 placebo-controlled clinical studies involving the use of 11 different AEDs showed that patients receiving AEDs had approximately twice the risk of suicidal thinking or behavior compared to patients receiving placebo. AEDs should be administered cautiously in patients with depression or other psychiatric disorders; phentermine-topiramate should be avoided in patients with history of suicidal attempts or active suicidal ideation. The risk of suicidal thoughts and behavior should be carefully assessed against the risk of untreated illness, bearing in mind that epilepsy and many other conditions for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Patients, caregivers, and families should be alert to the emergence or worsening of signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts or behavior. If patients have symptoms of suicidal ideation or behavior, a dosage reduction or treatment discontinuation should be considered.