In its Angina Pectoris warning, the prescribing information for propranolol hydrochloride tablets says there have been reports of exacerbation of angina and, in some cases, myocardial infarction, following abrupt discontinuance of propranolol therapy. A general FDA consumer page on managing the benefits and risks of medicines says that if you stop the medicine or want to use the medicine differently than directed, consult with your health care professional. The sources used here do not say how these warnings apply to occasional single-dose use, and this guide does not say that they do or do not.
What the label says about stopping
The same label says that when discontinuance of propranolol is planned, the dosage should be gradually reduced over at least a few weeks and the patient should be cautioned against interruption or cessation of therapy without the physician's advice. It then says that, since coronary artery disease may be unrecognized, it may be prudent to follow that advice in patients considered at risk of having occult atherosclerotic heart disease who are given propranolol for other indications.
These three label statements have three different subjects: reports after abrupt discontinuance, the manner of a planned discontinuance, and patients considered at risk of having occult atherosclerotic heart disease who are given propranolol for other indications. The first is under the Angina Pectoris heading and, as quoted here, does not name a patient group. The text used here does not list the other indications.
The FDA consumer page is general and is not about propranolol. As quoted here, its sentence about stopping does not name a medicine, a group of patients or a length of use.
Other heart-related warnings, with who each is about
| Label heading or topic | Who the wording names | What it says |
|---|---|---|
| Cardiac Failure | Patients with congestive heart failure | Sympathetic stimulation may be a vital component supporting circulatory function, and its inhibition by beta blockade may precipitate more severe failure. |
| Continued use of beta blockers | Patients without a history of heart failure | Continued use of beta blockers can, in some cases, lead to cardiac failure. |
| Major Surgery | Chronically administered beta-blocking therapy | It should not be routinely withdrawn prior to major surgery, however the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures. |
| Thyrotoxicosis | Hyperthyroidism | Beta-adrenergic blockade may mask certain clinical signs of hyperthyroidism. Therefore, abrupt withdrawal of propranolol may be followed by an exacerbation of symptoms of hyperthyroidism, including thyroid storm. |
| Wolff-Parkinson-White Syndrome | Patients with that syndrome and tachycardia | Beta-adrenergic blockade has been associated with severe bradycardia requiring treatment with a pacemaker. |
Contraindications and two interactions
The label says propranolol is contraindicated in cardiogenic shock; sinus bradycardia and greater than first degree block; bronchial asthma; and in patients with known hypersensitivity to propranolol hydrochloride. The first three items are conditions; only the last names a group of patients.
On interactions, the label says there have been reports of significant bradycardia, heart failure, and cardiovascular collapse with concurrent use of verapamil and beta-blockers. It also says the antihypertensive effects of clonidine may be antagonized by beta-blockers and that propranolol should be administered cautiously to patients withdrawing from clonidine. The verapamil statement is about concurrent use of verapamil and beta-blockers. The clonidine statement names patients withdrawing from clonidine.
What this does not tell you
Each warning is about the group or situation it names. The sources used here do not say how any of them apply to occasional single-dose use, and this guide does not say that they do or do not. Much of the wording is hedged, for example "may", "in some cases" and "there have been reports of", and none of it gives a rate or a number for how often any of these events happen. This guide is not advice to start, stop or change anything. The label points to the physician's advice and the FDA consumer page points to consulting a health care professional. A licensed provider decides whether propranolol is appropriate for a person.