Epilepsy - Long-Term Treatment

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• Fatigue and sleepiness
• Changes in appetite and weight
• Loss of coordination
• Gastrointestinal problems
• Possible bone loss leading to osteoporosis, even in young people. The older medications, such as phenytoin, phenobarbital, carbamazepine, and primidone, have more severe effects than valproic acid and the newer drugs. Many of the latter drugs, however, also pose some risk. Patients should ask their doctors about taking calcium and vitamin D supplements, a bone-protecting exercise regimen, and monitoring with bone densitometry.
• Changes in skin and hair, including acne from phenytoin, excessive hair growth from phenytoin and carbamazepine, and hair loss from valproate
• Reproductive problems
• Severe allergic reactions (particularly from particularly phenytoin, carbamazepine, phenobarbital, and primidone). They can include severe skin rashes, fever, and occasionally even inflammation or swelling of the liver, kidneys, or lymph nodes.

Drug Interactions

AEDs interact with many other drugs, making them more or less potent, so it is very important that patients inform their doctor of everything they are taking, including over-the-counter medications and vitamins. Some specific interactions are covered later in discussions of individual drugs. Many of the AEDs have some common effects on other medications; several reduce the effectiveness of oral contraception, for example. Erythromycin and some drugs used to treat asthma, ulcers, and heart disease can interact with AEDs.

Discontinuing Drug Therapy

An estimated 60% of all patients treated effectively can stop taking AEDs within 5 - 10 years. Evidence in 2002 suggests that medications in children should not be halted for at least 2 years after the last seizure, particularly if they have partial seizures and abnormal EEGs. It is not clear whether children who have been free of generalized seizures need to wait more than 2 years or if they can withdraw earlier. There is also no clear evidence on whether adults who are free of any seizure type can safely withdraw from their medications within 2 years of their last seizure of if they should wait.

In any case, attempts to halt drugs should be done during periods when seizures will cause the least harm. For instance, the best time to test the effects of drug withdrawal in teenagers might be about a year before they are eligible to drive.