Federal health regulators are ordering companies that make epilepsy drugs to add warnings about increased risks of suicide to their products.

The new warnings apply to blockbuster drugs used by millions of patients to control seizures. The drugs include GlaxoSmithKline's Lamictal, Johnson & Johnson's Topamax and Pfizer's Lyrica.

The FDA stopped short of adding its sternest warning to the medications, as it had proposed doing earlier in the year. In July a panel of outside experts recommended against adding the so-called "black box" warning, the strongest type available.

Anti-seizure drugs are used for a variety of illnesses in addition to epilepsy, including migraines, certain nerve-pain disorders, and psychiatric diseases such as bipolar disorder.