There are possible side effects with Viagra® (sildenafil citrate) that may be with any medicine. Many people tolerate this drug well. In early research studies, up to 2.5 percent of people taking
cialis stopped their medicine because of side effects.
Most Common Side Effects are,
* Headaches --in up to 16 percent of people
* Urinary tract infections (UTI) -- up to 3 percent
* Vision problems, including trouble telling the difference between blue and green, increased sensitivity to light, or blurred vision -- up to 3 percent
* Diarrhea -- up to 3 percent
* Dizziness -- up to 2 percent
* Unexplained rash -- up to 2 percent.
* Facial flushing -- up to 10 percent
* Indigestion, known as dyspepsia -- up to 7 percent
* Nasal congestion -- up to 4 percent
* Respiratory tract infections
* Back pain
* Flu-like symptoms
* Joint pain.