Propranolol is a 1st generation beta-blocker that originally was marketed as Inderal but is now available in generic form. Propranolol has been around since the 1960s and today has a wide range of uses. The British scientist, J. W. Black, who first developed propranolol, received the 1988 Nobel Prize in medicine for his work.
Different uses require different doses and treatment durations. Therefore, propranolol is available as tablets, capsules, and liquid solutions, in doses ranging from 10 mg to 160 mg (with suspended release). It’s even available as an intravenous solution for direct injection into the bloodstream. Propranolol is one of the 50 most prescribed drugs in the United States.
Helping treat patients with high blood pressure (hypertension) was the original purpose of propranolol. Propranolol works by blocking adrenaline’s constricting effect on blood vessels, which allows them to widen and allow more blood to pass through. This widening of blood vessels reduces a person’s blood pressure. Until the mid-2000s, propranolol was often a physician’s first treatment choice for hypertension. Nowadays, propranolol and other beta-blockers have fallen out of favor, as there are more effective hypertension treatments available. This is particularly true for elderly patients, based on the concern that long-term use of beta-blockers may raise a patient’s risk of developing type-2 diabetes.
Beta-blockers are used in the treatment of an irregular heartbeat (cardiac arrhythmias) and angina pectoris (chest pain because of insufficient blood flow to the heart muscle). They are also prescribed as a preventative treatment after a person has suffered a heart attack.
A common prescription purpose of propranolol today is to treat performance anxiety (stage fright, test anxiety, etc.). It’s not entirely clear why it works, other than by blocking adrenaline and lowering blood pressure, but propranolol has a good track record as a one-off treatment for performance anxiety. It helps that the drug is fast-acting: the effect starts 30 to 60 minutes after taking a pill. The consensus in the medical community now holds that propranolol is a better choice than benzodiazepines (such as Valium and Xanax) because — when used infrequently — it has fewer side effects and is not addiction-forming.
When treating essential tremors, propranolol is one therapy often chosen by doctors as it reduces the amplitude of tremors in up to 70% of cases. Propranolol is most effective for treating tremors in the upper and lower limbs and less successful in treating the rarer head and voice tremors.
Regular use of propranolol can lower the occurrence and intensity of migraines and cluster headaches. It doesn’t help against ongoing migraines and headaches like painkillers would, but it can lower your chances of getting a headache in the first place. This preventive effect owes to propranolol’s blood pressure-lowering function. Of course, this only applies to migraines and headaches that are blood pressure-related. It also means that people who get fewer migraines because of using propranolol, in most cases would also get fewer migraines if they were using other medications or methods to lower their blood pressure.
The symptoms of hyperthyroidism (excessive production of thyroid hormone) can be treated with propranolol and other common beta-blockers. While beta-blockers won’t treat the underlying hormonal condition, they can effectively alleviate the symptoms, which usually include trembling, palpitations, and anxiety. In the case of propranolol, there is only a modest effect on thyroid-related symptoms, so that it is not normally prescribed for this purpose.
Recent research has shown that propranolol may be effective in treating post-traumatic stress disorder (PTSD) and phobias, as the drug blocks norepinephrine, a neurotransmitter responsible for memory consolidation. Propranolol also appears to reduce the emotional impact of already formed (consolidated) memories, like a fear of spiders or flying. However, more research will be needed to establish whether propranolol can cure such phobias.