Before you start any treatment with Apcalis SX, be sure to ask your healthcare provider if your heart is healthy enough.

If you're a man who uses nitrate drugs, like nitroglycerine, never take Apcalis SX. The combination of Apcalis SX and nitrates can make your blood pressure suddenly drop to unsafe levels. You could get dizzy, faint, or even have a heart attack or stroke. Nitrates are found in many prescription medications that are used to treat angina (chest pain due to heart disease).

If you are not sure, whether any of your medications contain nitrates, or if you do not understand what nitrates are, ask your healthcare provider or pharmacist.

Discuss your past/current medical history in detail with your doctor before beginning treatment with any new medication. Ask your doctor if your heart is healthy enough before starting with this medication.
Doctors advise against using Apcalis SX if you are allergic to any ingredient in it or if you use nitrate drugs, like nitroglycerine. The combined effect of Apcalis SX and nitrates can make your blood pressure suddenly drop. It can also make you dizzy, faint, or even have a heart attack or stroke.

If you experience any of the following serious side effects, stop taking Apcalis SX and seek emergency medical attention or notify your doctor immediately:

• sudden vision loss; 
• ringing in your ears, or sudden hearing loss; 
• chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling;
• irregular heartbeat; 
• swelling in your hands, ankles, or feet; 
• shortness of breath;
• vision changes;
• feeling light-headed, fainting; or
• penis erection that is painful or lasts 4 hours or longer. 

Less serious side effects may include:

• warmth or redness in your face, neck, or chest;
• stuffy nose;
• headache;
• upset stomach; or
• back pain. 

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.