Viagra or Sildenafil is the fist medicine created by Pfizer to treat the problem of erectile dysfunction. Erectile dysfunction is also termed as impotency and this health problem is experienced by men only. Erectile dysfunction is caused by other health problems such as heart disease, diabetes, surgical trauma, neuro problems, and psychological disorder. For this reason, drug intake has to be taken only under doctor’s advice because some drugs can cause dangerous side effects to the body. After the introduction of Viagra to the market, other impotency drugs came along and these are Cialis or Taldafil and Levitra or Vardenafil.

All these drugs are highly regulated that a prescription is needed upon purchase. In order not to cause any further problem to the health, it is always best to consult with your doctor. Once you get the right medication from your doctor, you are assured of the right treatment method.