The following information applies to the use of propranolol for chronic medical conditions. Because beta-blockers are used intermittently and at a lower dose for performance anxiety, side effects are likely to be milder or less likely to occur.
Concerning medical conditions. Propranolol is not recommended if you have asthma, a slow heartbeat (bradycardia), Raynaud's syndrome, overt congestive heart failure, or certain heart-rhythm disorders. In addition, tell your doctor if you have had lung diseases, heart, liver, or kidney disease, diabetes, severe allergies, or thyroid problems.
Drug interactions. Tell your doctor about any prescription and nonprescription medication you take, especially cimetidine (Tagamet); medication for migraine headaches, asthma, allergies, colds or pain; medication for heart disease or high blood pressure; reserpine; and vitamins.
Side effects. Report the following reactions to your doctor immediately: a slow, irregular heartbeat, difficulty breathing, a sore throat, unusual weight gain, swelling of the feet or hands, unusual bleeding, or chest pain. Side effects reported in studies of beta-blockers for performance anxiety include gastrointestinal distress, headaches, insomnia, nightmares, hallucinations, dizziness, lethargy, depression, low blood pressure, and a slowed heart rate.
Surgery. If you're having surgery, tell your doctor or dentist that you use propranolol, which might increase the risks associated with anesthesia.
Pregnancy. A slow heart rate, respiratory depression, and low blood sugar have been reported in newborns whose mothers took beta-blockers during pregnancy. Tell your doctor if you're pregnant, plan to become pregnant, or are breast-feeding.