Zhewitra 20 mg contains vardenafil, a medication used to treat erectile dysfunction (ED) by improving blood flow to the penis. While Zhewitra primarily affects the cardiovascular system, its effects on the nervous system are linked to its mechanism of action and potential side effects. One of the most common side effects of vardenafil (and other PDE5 inhibitors like sildenafil) is headaches. These occur due to the drug’s action of increasing blood flow, which can cause mild pressure changes in the brain. Some individuals may experience dizziness, especially when standing up quickly. This is related to the vasodilation effect (widening of blood vessels) that lowers blood pressure, which can affect the brain's blood supply. Flushing or a sensation of warmth, often seen in the face or chest, is another side effect, which may also be linked to changes in blood flow and nervous system responses. While rare, Zhewitra 20 mg may affect the peripheral nerves, causing sensations like tingling or a slight numbness. This is often transient and not typically harmful. This is a rare but serious side effect that can result from the use of vardenafil. It involves a prolonged, painful erection lasting longer than four hours. Although this is a vascular issue, it can also affect nerve function due to prolonged pressure and lack of oxygen in the penis. For some men, the use of vardenafil may heighten the sensory experience during sexual activity. This is because the drug enhances the natural process of achieving an erection, which involves complex interactions between the brain, nerves, and blood vessels.