Viagra is the most recognizable brand name of the erectile dysfunction (ED) medication Sildenafil Citrate. Brought to the market by Pfeizer, it has remained a top the ED food chain with Cialis (Tadalifil) and Levitra (Vardenafil) being its biggest competitors. Cialis is perhaps its strongest competitor, but Viagra holds the distinction of being first. Viagra first hit the market in 1998 and was met with open arms by millions of men who otherwise had given up on sexual activity. Since that time, the ED medication has only grown in popularity and shows no signs of slowing down.

Viagra Functions & Traits:

Sildenafil Citrate is phosphodiesterase type 5 inhibitor (PDE5 Inhibitor) that was designed for the sole purpose of treating erectile dysfunction. Viagra only carries a half-life of a couple hours, which means it must be used when sexual activity is planned. For this reason, many men have begun to opt for Cialis as it will keep a man primed for sexual activity for up to 36 hours, whereas Viagra for only 4 hours.

Sildenafil Citrate’s primary purpose is to increase blood flow into the penis, which is what creates an erection. The penile arteries are relaxed, which is followed by a release of nitric oxide from the nerves to the endothelial cells of the penis. Once this process is met, cGMP is then synthesized and an erection then ensues.

Important note – As with all ED pills, Viagra will not promote an erection without sexual stimulation. This is due to nitric oxide being released, which is not released without sexual stimulation.

Like Tadalafil, Sildenafil has other uses beyond treating ED. The drug has been approved to treat pulmonary hypertension or more specifically pulmonary arterial hypertension (PAH). The drug functions by simply relaxing the arterial wall, thereby reducing pulmonary pressure. The medication has also been recently found to treat altitude sickness or altitude related edema.

Side Effects:

Viagra, as with all PDE5 inhibitors is a relatively side effect friendly medication. Side effects of Viagra do exist, but they are not extremely common and are normally manageable if they occur. However, while not fully understood, Viagra does appear to be a little more side effect prone than its counterpart Cialis. Like Cialis, the most worrisome side effect is vision impairment. Vision impairment is rare with Viagra and Cialis, but there have been more complaints of blurred or discolored vision with Viagra. Other possible side effects of Viagra include:

• Indigestion
• Nausea
• Flushness
• Lower back pain
• Headache
• Hypotension
• Loss of hearing (sudden) 

Those who use Viagra should ensure they are healthy enough for use. Nitrates should be avoided when using Viagra as this may cause a sudden or rapid decrease in blood pressure (hypotension). Those who have existing liver damage, renal failure or a recent heart attack or stroke should not take Viagra or any ED medication.

Dose & Administration:

Viagra is available in three specific strengths, 25mg, 50mg and 100mg tablets. 50mg one hour prior to sexual activity is the normal starting point. Some men may find that the dose can be reduced to 25mg while others may need the larger 100mg dose. Regardless of the dose, the medication should not be taken more than once per day. If taken for the purpose of treating PAH, the 25mg form under the name Ritonvir will be used and should not exceed this amount in a 48hr period.