Take this medication by mouth with or without food as directed by your doctor, usually once daily. Swallow the capsules whole. Do not crush or chew the capsules. Doing so can release all of the drug at once and may increase your risk of side effects.

If you have trouble swallowing the capsule, you may open the capsule and carefully sprinkle its contents on a spoonful of soft, cool applesauce just before you take it. Swallow all of the drug/food mixture right away. Do not chew the mixture. Then rinse your mouth and swallow the rinse liquid to make sure that you have swallowed all of the medicine. Do not prepare a supply in advance.

Your doctor may gradually increase your dose. Follow your doctor's instructions carefully. The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Use this medication regularly to get the most benefit from it. To help you remember, use it at the same time each day. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick. For the treatment of high blood pressure, it may take 2 to 4 weeks before you get the full benefit of this drug.

This medication must be taken regularly to prevent angina. It should not be used to treat angina when it occurs. Use other medications (such as nitroglycerin placed under the tongue) to relieve an angina attack as directed by your doctor. Consult your doctor or pharmacist for details.

Tell your doctor if your condition does not get better or if it gets worse (for example, your blood pressure readings remain high or increase, your chest pain worsens).