Propranolol, sold under the brand name Inderal among others, is a medication of the beta blocker class. It is used to treat high blood pressure, a number of types of irregular heart rate, thyrotoxicosis, capillary hemangiomas, performance anxiety, and essential tremors. It is used to prevent migraine headaches, and to prevent further heart problems in those with angina or previous heart attacks. It can be taken by mouth or by injection into a vein. The formulation that is taken by mouth comes in short-acting and long-acting versions. Propranolol appears in the blood after 30 minutes and has a maximum effect between 60 and 90 minutes when taken by mouth.
Common side effects include nausea, abdominal pain, and constipation. It should not be used in those with an already slow heart rate and most of those with heart failure. Quickly stopping the medication in those with coronary artery disease may worsen symptoms. It may worsen the symptoms of asthma. Caution is recommended in those with liver or kidney problems. Propranolol may cause harmful effects in the baby if taken during pregnancy. Its use during breastfeeding is probably safe, but the baby should be monitored for side effects. It is a non-selective beta blocker which works by blocking β-adrenergic receptors.
Propranolol was patented in 1962 and approved for medical use in 1964. It is on the World Health Organization’s List of Essential Medicines, the most effective and safe medicines needed in a health system. Propranolol is available as a generic medication. The wholesale cost in the developing world is between US$0.24 and US$2.16 per month as of 2014. In the United States it costs about $15 per month at a typical dose. In 2016 it was the 43rd most prescribed medication in the United States with more than 18 million prescriptions.