- Various common (and usually minor) side effects sometimes result from using Tenormin. If these side effects become problematic for you, inform your physician. These side effects include drowsiness, cold toes and fingers, dizziness, diarrhea, exhaustion, nausea and feelings of weakness.
- Serious side effects are also a possibility with Tenormin, though are generally uncommon. If you think that you are experiencing serious side effects of the beta-blocker, get emergency medical attention. These side effects include moodiness; swelling of the feet, hands, or ankles; impaired sexual ability; blue palms, toenails, or fingernails; abnormal bleeding or bruising; abnormal weight gain; lingering lightheadedness or dizziness; strangely slow heartbeat, shortness of breath and passing out.
- Some people also develop severe allergic reactions as a result of taking Tenormin. These reactions are considered to be serious, and require emergency medical help. Some signs of allergic reaction to Tenormin are chest tightness; hives; skin rash; breathing problems; and swelling of the lips, tongue, mouth or face.
- Not everyone is a good candidate for taking Tenormin, such as those who have heart conditions (like a blockage, or a slow heartbeat) and those with atenolol allergies. It is also very important that people considering the medication inform their doctor of all medical conditions, especially depression, emphysema, asthma, bronchitis, kidney or liver disease, congestive heart failure, sick sinus syndrome, circulation problems (like Raynaud's syndrome), pheochromocytoma, myasthenia gravis, diabetes, thyroid disorder and low blood pressure.
- If you have taken excessive amounts of Tenormin and are worried that you have overdosed, immediately get emergency medical care. Some symptoms of Tenormin overdose are shortness of breath, dizziness, uneven heartbeats, weakness, seizures, fingernails that are bluish in color, and passing out.