A minority of patients with retinitis pigmentosa have generic disorders of retinal phosphodiesterases. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. However, the dose is usually not more than 80 mg 3 times a day. Side effects Side effects of oral ED medicines are often mild. Avanafil Stendra. There is no safety information on the administration of sildenafil to these patients and sildenafil should be administered with caution. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. · What is Kamagra? Kamagra is sold as a tablet you can take to improve your sex drive (libido) and erectile dysfunction, but it is not guaranteed to be safe for you to use. Kamagra is manufactured in India and is not approved for use in the EU. It is illegal to purchase or sell Kamagra in the UK. Kamagra 50 MG Tablet contains Sildenafil. It is better known as the blue pill. It is an effective medicine used for the treatment of erectile dysfunction (ED) in men. Erectile dysfunction is a condition where a man is unable to achieve and/or maintain an erection adequate for sexual intercourse. Kamagra 50 MG Tablet or Viagra is the most commonly used drug for the treatment of erectile dysfunction. It also treats other male sexual function problems. The sildenafil citrate is the salt form of the drug. It is generally used to increase blood flow to the penis to help a man sustain his erection to enhance sexual activity.