There is no need to rush to put people on drugs if they have only infrequent seizures, say UK doctors.
Seizures can be controlled by drug therapy
Delaying medication does not increase the risk of chronic epilepsy or have a negative impact on quality of life, a study in the Lancet shows.
Waiting until treatment is absolutely necessary also avoids unnecessary drug side effects, say the Liverpool University authors.
Epilepsy charities said management should be tailored to the individual.
Professor David Chadwick and colleagues recruited about 1,400 people with single or infrequent seizures.
Half were given antiepileptic drugs carbamazepine or valproate immediately, while the other half did not receive any treatment until they and their clinician agreed it was necessary.
The researchers followed up what happened to the patients for the next five years.
Immediate drug treatment reduced the likelihood of a repeat seizure in the short term, but over the course of the study both interventions resulted in similar rates of seizure recurrence.
There was no difference in quality of life between the two groups and delaying treatment led to fewer reports of side effects.
Professor Chadwick said: "At two years, the benefits of improved seizure control with immediate treatment seem to be balanced by the unwanted side effects of drug treatment and there is no improvement in measures of quality of life."
Samuel Berkovic from the Epilepsy Research Centre at Melbourne University, Australia, said: "The results of this study suggest there is little to gain in the long-term from starting medication immediately."
Professor Ley Sander of the National Society for Epilepsy said: "This is a most interesting study and it confirms the current practice of deferring treatment for most people presenting with a first unprovoked epileptic seizure.
"Indeed, it provides solid evidence for the practice. It also confirms the effectiveness of anti-epileptic drugs in the short term as well as the fact that for the majority of people who develop epilepsy, the outcome is good."
Epilepsy Action said the timing of starting treatment often depended on the clinician involved and the patient's individual circumstances.