Who Should Not Take Cialis, Levitra or Viagra?
Side effects are not common but they can occur. Side effects can include: • Headache • Upset stomach or ‘ heartburn’ • Flushing (feeling warm) • Nasal congestion • Changes in vision (color, glare) • Back pain (with Cialis) Call your doctor if you experience severe forms of these symptoms or if they do not go away after 4-8 hours.