Diltiazem is a calcium channel blocker. Calcium is involved in blood vessel contraction and in controlling the electrical impulses within the heart. By blocking calcium, diltiazem relaxes and widens blood vessels and can normalize heart rates. Diltiazem is used to treat chest pain (angina) or high blood pressure.
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 bloating, heartburn, muscle cramps, headache, flushing, nasal congestion, sore throat, constipation or diarrhea. Inform your doctor if they become bothersome. Notify your doctor if you develop: breathing difficulties, swelling of the hands or feet, an irregular heartbeat. If you notice other effects not listed above, contact your doctor or pharmacist.