Malegra works by blocking the PDE5 enzyme, which increases levels of cGMP in the penile tissues. This causes relaxation of blood vessels and improves blood flow, making it easier to achieve and maintain an erection. It only works when a man is sexually aroused and does not increase sexual desire. Malegra should not be taken with nitrate medications (used for chest pain), as this can cause a dangerous drop in blood pressure. Caution is also needed in people with heart disease, liver or kidney problems, or those taking interacting medicines. https://www.genericday.com/malegra.html