• Cialis is a prescription medicine taken by mouth to treat male sexual function problems by blocking a certain enzyme in the body. In combination with sexual stimulation, cialis helps blood flow into the penis to achieve and maintain an erection.

How should you take this medication?

• This drug is taken by mouth as needed, at least 30 minutes before sexual activity with or without food.
   
• Cialis can be taken with or without food.
   
• Do not take cialis more than once a day. Allow 24 hours to pass between doses.

General Precautions with Cialis

• Before taking Cialis, tell your doctor or pharmacist if you are allergic to it or if you have any other allergies.
   
• Do not take cialis if you are also using a nitrate drug for chest pain or heart problems. This includes nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate.
   
• Contact your doctor or seek emergency medical attention if your erection is painful or lasts longer than 4 hours.
   
• Do not drink alcohol to excess when taking tadalafil. When taken in excess alcohol can increase your chances of getting a headache or getting dizzy, increasing your heart rate, or lowering your blood pressure.

What are the possible side effects of Cialis?

• If you become dizzy or nauseated, or have pain, numbness, or tingling in your chest, arms, neck, or jaw during sexual activity, stop and call your doctor right away.
   
• Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
   
• Continue taking Cialis and talk with your doctor if you have any of these less serious side effects: arm and leg pain, back pain, flushing, headache, indigestion, muscle aches, nasal congestion