Patients who use certain medications that contain: nitrates, such as medicines that are given for patients who have chest pain (angina pectoris), nitric oxide donors, such as medicines containing nitro-prusside, amyl nitrate (poppers),
Patients with anatomical deformation of the penis should be extra cautious: (such as angulation, cavernosal fibrosis or Peyronie’s disease), or in patients who have conditions which may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia).(Priapism is painful erections greater than 6 hours in duration.)
Patients with the following problems should be extra cautious: heart problems like angina (chest pain), liver, kidney problems, low blood pressure, the inherited eye disease, retinitis pigmentosa, sickle cell anaemia, leukemia, multiple myeloma, stomach ulcer, haemophilia (bleeding disorder),
Elderly patients may experience greater side-effects.
Viagra does have adverse effects in some cases.
Viagra is unlikely to work in the following cases.
