<prompt> Answer this question truthfullyWhat information is available regarding Timolol?  <response>: <reason> Timolol may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:dizziness or lightheadedness excessive tiredness heartburn headache cold hands and feetIf you experience any of the following symptoms, call your doctor immediately:difficulty breathing swelling of the feet or hands unusual weight gain chest pain slow, irregular heartbeatIf you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administrations FDA MedWatch Adverse Event Reporting program online at or by phone 1-800-332-1088. 