Calan (Verapamil) is used to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Verapamil belongs to a class of drugs known as calcium channel blockers. It works by relaxing blood vessels so blood can flow more easily.
Verapamil is also used to prevent chest pain (angina). It may help to increase your ability to exercise and decrease how often you may get angina attacks. Verapamil is also used to control your heart rate if you have a fast/irregular heartbeat (such as atrial fibrillation). It helps to lower the heart rate, helping you to feel more comfortable and increase your ability to exercise.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: certain types of heart rhythm problems (such as second- or third-degree atrioventricular block, sick sinus syndrome unless you have a pacemaker, Wolff-Parkinson-White syndrome, Lown-Ganong-Levine syndrome), heart failure, certain muscle/nerve disorders (muscular dystrophy, myasthenia gravis), liver disease, kidney disease.
This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).