Viagra, the world’s #1 prescription drug for erectile dysfunction, is a billion-dollar blockbuster. But how long does it stay in your system? More importantly, is it safe to assume that every dose is equally effective the whole time? Let’s dive into the science behind Viagra and find out what happens when you pop this drug.
Quick Overview
As the name would suggest, Viagra is a treatment for erectile dysfunction. If you’re not familiar, erectile dysfunction is the inability to achieve or maintain an erection during sexual stimulation. It’s most common among men over the age of 60, and its prevalence rises with age. In fact, over 300 million men worldwide are now classified as having some form of erectile dysfunction. And if that doesn’t get you interested, the fact that it’s a $32 billion global industry surely will.
The concept of treating erectile dysfunction with a drug was first introduced in the 1950s. Since then, a combination of Sildenafil (a chemical compound found in Viagra) and Dapoxetine (a serotonin reuptake inhibitor) have been proven to improve erectile function and allow men to maintain an erection for longer. In fact, in all of its various formulations (including the branded drug Versatis), Viagra has been proven to increase the duration of erections by 25-50% and increase the peak intensity of erections by 20-40% when compared to placebo (a dummy pill). Most importantly, clinical studies have shown that Sildenafil is more effective than Viagra in treating erectile dysfunction when used in combination with Dapoxetine, and that the two drugs work better together than either of them does on its own. In other words, this is a much more effective treatment for erectile dysfunction than you might expect from a single pill.
How Long Does Viagra Stay in Your Body?
There are several factors that determine how long a drug will stay in your system. First and foremost, the type and method of administration of the drug itself. For example, oral administration of Viagra will result in a much shorter duration of action (and hence less frequent dosing) than its intramuscular injection counterpart.
Next, you have to consider the protein binding of the drug. Proteins are vital for various biological functions, and they can either bind or unbind to drugs, depending on their structure. Unsurprisingly, many proteins are responsible for transporting drugs around the body as well as removing them from the system once they’ve served their purpose. Different proteins will have varying affinities for different drugs, meaning that the duration of action will vary from one drug to the next. There are examples of extremely long-lived proteins in the human body, such as albumin and immunoglobulins. While these proteins will bind to and hence retain the effect of most drugs, they will not bind to or affect the action of some chemically related compounds. For instance, the anticoagulant warfarin will bind to albumin and prolong its half-life by 7-9 days, while not binding to or affecting the action of its derivatives, such as coumarin (also found in warfarin).
With that in mind, let’s examine the specific case of Viagra. As mentioned earlier, Sildenafil is the primary active ingredient in the drug, and it is related to the chemical compound vinblastine in terms of its mechanism of action. Sildenafil is a potent inhibitor of PDE5, the enzyme that breaks down cGMP (cyclic Guanosine Monophosphate) in the body. Inhibition of this enzyme prevents the degradation of cGMP, leading to increased nitric oxide production and smooth muscle relaxation in the corpus cavernosum (the shaft and the head of the penis) and in the urethra. As a result, increased blood flow is required for an erection to occur, and this is what Sildenafil brings to the party. Inhibition of PDE5 by Sildenafil prevents the degradation of cGMP, resulting in increased blood flow into the penis and ultimately an erection. Based on this, it is not very surprising that Sildenafil has a short half-life of 3-5 hours in the bloodstream. However, this does not mean that it is cleared instantaneously from the body. Once Sildenafil enters the systemic circulation, it will be captured by the liver and undergo biotransformation into an inactive metabolite, which is then excreted into the bile in relatively stable amounts. Hence, the half-life of Sildenafil in your system is much longer than the 3-5 hours predicted for a typical drug, and it varies between 8 and 12 hours, based on different pharmacodynamic parameters such as concentration and protein binding. This is because the liver is responsible for metabolizing various drugs into their inactive counterparts, and this process takes time.
Safety
Another thing to consider when assessing the duration of action of a drug is its safety profile. In general, you want to avoid drugs that have a long half-life, as they will accumulate in the body over time and hence be present at higher concentrations than needed for the desired therapeutic effect. As discussed in the previous paragraph, Sildenafil is a short-lived drug and hence is generally considered to be safe. However, this does not mean that it is without its flaws. As noted by Janssen, a pharmaceutical company that manufactured Sildenafil, it can interact with a variety of drugs and foods that are metabolized by the liver. This is why it is always a good idea to consult with your doctor or a pharmacist before starting any new medication, especially if you are taking other medications as well.
Conclusion
In conclusion, Viagra is a short-lived drug that allows men to maintain an erection for a relatively short period of time. However, this is also what makes it such a tempting drug to experiment with, as it will have the desired effect for a limited amount of time before it is degraded or eliminated from the body. Sildenafil is considered to be safe when used in combination with Dapoxetine, but it can interact with other drugs and foodstuffs metabolized by the liver. Therefore, it is always a good idea to consult with your doctor or a pharmacist before starting any new medication, especially if you are taking other medications as well, as this could potentially raise the risk of adverse events.