Viagra, the trade-name for the drug Sildenafil, is a commonly prescribed medication for treating erectile dysfunction and pulmonary arterial hypertension. Viagra was developed at the pharmaceutical company Pfizer by scientists Andrew Bell, David Brown, and Nicholas Terrett to treat various cardiovascular disorders. It was discovered in clinical trials in the United Kingdom that it was not effective in reducing high blood pressure or treating angina pectoris. However, it was noted that it could cause penile erections. Pfizer patented the drug in 1996 and received FDA approval for use to treat erectile dysfunction in 1998. Viagra is the first oral drug approved to treat erectile dysfunction. Viagra is now one of the most successful treatments for erectile dysfunction, with annual sales of at least US $1 billion. Its main competitors are Cialis and Levitra.
Viagra works via a metabolic pathway involving nitric oxide and smooth muscle vasodilation discovered by Nobel Prizewinners Robert Furchgott, Ferid Murad, and Louis Ignarro. Specifically, Viagra prevents degradation of cyclic guanosine monophosphate (cGMP). Nitric oxide binds to receptors that increase levels of cGMP, which results in smooth muscle relaxation within the penis. This leads to increased blood flow in the spongy parts of the penis and causes an erection.
Recently, Viagra has seen increased usage as a recreational drug due to its effectiveness in treating erectile dysfunction. Some people believe that Viagra can also lead to an increase in libido, sexual ability, or penis size. However, there are no studies that prove that these are caused by Viagra. Because Viagra works by relaxing smooth muscles and improving blood flow, some athletes now take Viagra to improve blood flow to their muscles, thus supposedly improving their performance.
The most common adverse effects of using Viagra are headaches, flushing, indigestion, nasal congestion, and impaired vision. The most common complaint for impaired vision is cyanopsia, or seeing everything with a blue tint. More rare adverse effects include prolonged erections, severe low blood pressure, stroke, hearing loss, and heart attacks. Viagra can also cause an erection lasting more than 4 hours. Seek immediate medical help if you experience any of these symptoms. Viagra should not be taken with protease inhibitors, which are common for treating HIV infections, or with hypertension drugs such as an alpha-1 blocker. Viagra also should not be taken with nitrates. Always consult your doctor about your medical history before using Viagra.
Typically, Viagra is prescribed in 25, 50, and 100 mg pills, and may be offered in either a bottle format or in single pill packaging. The recommended starting dose for most men is 50 mg. Viagra should be taken at most once per day. Viagra usually starts to work within 30 to 60 minutes. However, it can also be taken up to 4 hours before sexual activity. It is important to note that Viagra by itself cannot cause an erection. Viagra only works in conjunction with sexual stimulation. Viagra can be taken without food or drink. Viagra should not be taken with excessive amounts of alcohol. If Viagra does not work the first time, it may have more effectiveness the next time you use it. Doctors advise trying it eight times before moving to a higher dosage of Viagra.
Viagra must be prescribed to you in order for it to be purchasable in a pharmacy. It is not available over the counter in Australian pharmacies. However, in Australia, it is possible to find many online outlets and retailers that offer Viagra and its generic counterpart, sildenafil. There is always a risk that these online retailers may be selling counterfeits of Viagra rather than the real drug. You should always search for refutable and well-regarded online vendors when purchasing Viagra through the Internet. A simple Google search shows many online vendors, such as Ozpills.com and Simpleonlinedoctor.com.au, that offer Viagra and its generic counterpart, sildenafil. Viagra begins at around A$30 while the generic counterpart, sildenafil, is much cheaper. All dosages (25, 50, and 100 mg) are available, and single pill packaging and bottle formats are often available. Note that because of Viagra’s popularity, many sites on the Internet may claim to sell blue tablets that imitate the shape and color of the real Viagra product. Other sites may claim to sell “herbal Viagra” or herbal aphrodisiacs that contain minimal or counterfeit Viagra analogs. Viagra may also b called “vitamin V” or the “blue pill” in product descriptions. Always take due diligence and research the online retailer selling your Viagra product before purchasing.
Medical Practitioner (General Practice) with postgraduate diplomas in Cape Town. My special interest is erectile dysfunction.