Although rare, Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil) can cause muscle pain and unusual skin sensations or paresthesia. In clinical studies, Viagra caused muscle pain and paresthesia in less than 2% of patients. Patients who experience these side effects should stop taking the medication and consult their physician. These medications increase blood flow to the penis by inhibiting the enzyme phosphodiesterase type 5 (PDE5). The most common side effects of Viagra and the other PDE5 inhibitors are flushing and headache. PDE5 drugs can cause dangerously low blood pressure if they are taken with nitroglycerin or other nitrate medications that are used to treat chest pain and heart disease.
In patients that cannot tolerate PDE5 inhibitors there are other treatments available. The drug alprostadil (Caverject, Edex, Muse) also increases blood flow to the penis leading to an erection. These medications are not as popular because they have to be injected with a small needle into your penis, or a small suppository must inserted into the opening of the penis. Mechanical devices such as vacuum erection pumps are safe and highly effective in many men. Consult your physician for more information about treatment options for male enhancement.
Many thanks for your reply.
I was recently in hospital for an operation and over those 10 days my symptoms went away which I suppose makes it likely that my symptoms come from an environmental factor such as something I'm taking in every day life.