Propranolol: uses, side effects and what to know

Propranolol is a non-selective beta-blocker: it blocks beta receptors in the heart and elsewhere in the body. According to MedlinePlus, it relaxes blood vessels and slows the heart rate, which improves blood flow and lowers blood pressure.

It is sold as generic propranolol tablets and oral solution, and as extended-release capsules under brand names such as Inderal LA and InnoPran XL. It is a prescription medicine. It is not a controlled substance: the FDA labels list no DEA schedule.

According to the FDA label for propranolol tablets, it is approved for the uses below. The extended-release capsules have fewer approved uses: Inderal LA for high blood pressure, angina, migraine prevention and hypertrophic subaortic stenosis; InnoPran XL for high blood pressure only.

The FDA has not approved propranolol for anxiety. Using it for anxiety, including performance anxiety (nerves before public speaking or a presentation), is an off-label use. MedlinePlus says it is sometimes used to treat anxiety and that you should talk with your doctor about the risks of using it for your condition.

So if anxiety is what you feel, the doctor first works out which kind it is and checks your heart, blood pressure and other medicines, then explains your options, which may or may not include a medicine. Read more about anxiety and mental health care by video.

If you are thinking about harming yourself, get help now. Call Línea PAS at 1-800-981-0023 or call or text 988, any time. If you are in immediate danger, call 911.

Migraine. Propranolol is approved to prevent migraine: it is taken every day so attacks come less often. The label states it is not for stopping an attack that has already started. If you have frequent attacks, read the migraine guide.

Essential tremor. Propranolol tablets are approved for familial or hereditary essential tremor, the shaking you notice in your hands when writing, eating or holding a glass. The label says it is not for tremor associated with Parkinson's. A new tremor deserves an evaluation to find its cause.

Label ranges for adults. For the tablets, the usual maintenance dose for high blood pressure is 120 to 240 mg a day, split into several doses; for angina, 80 to 320 mg a day; for migraine prevention, 160 to 240 mg a day; and for essential tremor, 120 mg a day is often enough. Inderal LA is taken once a day, and InnoPran XL once a day at bedtime.

The doctor decides the dose. Treatment starts low and is adjusted based on your pulse, blood pressure and response. Do not change it on your own. The tablet label states that safety and effectiveness in children have not been established. A propranolol oral solution for babies (Hemangeol) is approved to treat certain infantile hemangiomas; the tablets are not for children.

Side effects listed by the FDA label and MedlinePlus include:

The FDA label for propranolol has no boxed warning, but it does carry these important warnings:

• Asthma and airways: it can cause bronchospasm, which is why it is contraindicated in bronchial asthma. See asthma.
• Heart failure: it can worsen it, or bring it on in some people.
• Diabetes: it can hide the warning signs of low blood sugar, such as a racing heart, and MedlinePlus warns it may raise the risk of hypoglycemia. If you have type 2 diabetes, check your sugar and tell the doctor.
• Thyroid: it can hide the signs of hyperthyroidism, and stopping it suddenly can make it worse.
• Surgery: do not stop it before an operation on your own; tell the surgeon and the anesthesiologist you take it.
• Other: very low blood pressure, heart block, depression, hallucinations and severe skin reactions, which are rare.

Per the FDA label, stopping propranolol abruptly has been linked to worsening angina and, in some cases, heart attacks. MedlinePlus warns that stopping it suddenly can cause serious heart problems. If it needs to be stopped, the label says to lower the dose gradually over at least a few weeks. Do not stop it without talking with the doctor, even if you feel well. If you get chest pain after stopping it, call 911.

Before starting, tell the doctor everything you take, including supplements. According to the FDA label:

If you are pregnant, planning a pregnancy or breastfeeding, the decision is made with the doctor. Per the FDA label, there are no adequate studies in pregnant women; growth problems in the baby have been reported, and newborns exposed at delivery can have a slow heart rate, low blood sugar and breathing problems. That is why it is used only if the benefit justifies the risk. Propranolol passes into breast milk. If you become pregnant, do not stop it suddenly: talk with the doctor first.