There are a number of more serious side effects with Calan SR that you should report immediately to your healthcare provider. These include, but are not limited to:
Chest pain
An irregular heart rhythm (arrhythmia) or a slow heart rate (bradycardia)
Significant water retention, especially accompanied by difficulty breathing (signs of congestive heart failure or CHF)
Signs of low blood pressure, such as dizziness, lightheadedness, or fainting
Hallucinations or other psychotic problems
Breast enlargement in men (gynecomastia)
Signs of an allergic reaction, including an unexplained rash, hives, itching, unexplained swelling, wheezing, or difficulty breathing or swallowing.
Rare Calan SR Side Effects
There are other possible Calan SR side effects that can occur. These rare side effects occur in less than 1 percent of people taking the medication. For these side effects, it is difficult to tell whether the side effect is actually caused by Calan SR or something else.
Some of these rare Calan SR side effects include, but are not limited to: