Learn about the side effects of propranolol, from common to rare, for consumers and healthcare professionals. Propranolol tablets are a beta-blocker that treats high blood pressure, tremors and atrial fibrillation. It can also prevent migraine headaches. Propranolol (Inderal LA, Innopran XL) is a beta blocker that can treat many health conditions. Common propranolol side effects include low blood pressure, a slow heart rate, and nausea. You may feel dizzy, tired, or weaker than usual from these side effects, but these symptoms usually improve with time. Other possible propranolol side effects include erectile dysfunction, sleep issues, and. NHS medicines information on side effects of propranolol and what you can do to cope. Propranolol is a type of beta-blocker that helps the heart to beat slower and more steadily. Common side effects may include drowsiness, nausea, and diarrhea. Inderal (propranolol) is a beta blocker used to treat high blood pressure (hypertension), heart pain (angina), arrhythmia, and some neurologic conditions. Common side effects of Inderal include abdominal cramps, diarrhea, constipation, fatigue, insomnia, nausea, depression, dreaming, memory loss, fever, impotence, lightheadedness, slow heart rate, low blood pressure, cold extremities, sore. Propranolol may cause heart failure in some patients. Check with your doctor right away if you are having chest pain or discomfort, dilated neck veins, extreme fatigue, irregular breathing, an irregular heartbeat, swelling of the face, fingers, feet, or lower legs, or weight gain. This medicine may cause changes in your blood sugar levels. Common Side Effects Most people who take propranolol tolerate it well, but side effects are common enough that you should know what to expect. The most frequently reported issues are fatigue, low energy, and a general feeling of sluggishness. These tend to be dose-related: higher doses cause more noticeable tiredness. Propranolol is a beta-blocker that is used to treat high blood pressure, angina, anxiety, heart rhythm disorders, migraine prevention, and other heart or circulatory conditions. Find patient medical information for Propranolol (Inderal LA, Innopran XL, others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings.