By blocking calcium, verapamil relaxes and widens blood vessels and can normalize heartbeats. Ask your doctor or pharmacist about possible problems related to use of short-acting calcium channel blockers. This medication must be taken as directed to prevent chest pain. It is not effective if taken only when chest pain occurs. Do not stop taking this medication suddenly without your doctor's permission.
Chest pain can occur if the medication is stopped too fast.
Your dose may need to be gradually decreased. This drug may cause dizziness and lightheadedness especially during the first few days. Avoid activities requiring alertness. When you sit or lie down for a while, get up slowly to allow your body to adjust and minimize dizziness. You may also experience weakness, fatigue, nausea, muscle cramps, headache, flushing or constipation.