have low blood pressure (hypotension) have a rare inherited eye disease, such as retinitis pigmentosa. have sickle cell anaemia (an abnormality of red blood cells), leukaemia (cancer of blood cells) or multiple myeloma (cancer of bone marrow) have a deformity of your penis or Peyronie's disease (curved penis)
do not take sildenafil if you are taking or have recently taken riociguat (Adempas) or nitrates (medications for chest pain) such as isosorbide dinitrate (Isordil), isosorbide mononitrate (Monoket), and nitroglycerin (Minitran, Nitro-Dur, Nitromist, Nitrostat, others).
Sildenafil should not be used with any other medicine or device that causes erections. It is important to tell your doctor about any heart problems you have now or may have had in the past. This medicine can cause serious side effects in patients with heart problems.
Sildenafil does not improve sexual function in men without erectile dysfunction but does reduce the postorgasmic refractory time.
The effects of Viagra can last 4 to 8 hours, depending on the individual person and the dose you take. In fact, some people may experience more than one erection during this time.
Viagra blood levels peak an hour after you swallow the tablet on an empty stomach. According to Ramin, if you eat a large or high-fat meal and then take Viagra, the medication will lose its effectiveness and may take longer to start working.
These have shown that sildenafil causes a modest reduction in blood pressure, even when taken with other blood pressure-lowering drugs, providing reassurance on safety when taken as a single dose for erectile dysfunction.
Taking Viagra doesn't cause new or worsening ED. However, Viagra can sometimes cause priapism, which is a long-lasting and sometimes painful erection.
According to extensive data available to date, sildenafil citrate has been shown to pose minimal cardiovascular risks to healthy people taking this drug.
While rare, Viagra can cause an erection that lasts longer than 4 hours (priapism). This can result in permanent damage if left untreated. Vision changes are also possible.
The short answer is yes; you can take Viagra or its generic form, sildenafil, every day. Whether you need to or should, depends. Since each person is different, you should consult with a doctor about what's best for you. They can discuss dosage and frequency.
However, because Viagra is a vasodilator, it helps open up blood vessels and arteries. You might think that this would actually help to reduce the risk of a heart attack, but, there have been reports of heart attack, stroke, arrhythmia and even death in men taking Viagra.
For example, Viagra can cause prolonged erection. If not treated, this can lead to permanent erectile dysfunction. Viagra can also cause a serious eye condition called non-arteritic anterior ischemic optic neuropathy, which can lead to permanent vision loss. But these side effects were both rare in studies of the drug.
Can I take Viagra if I have high blood pressure? For many patients with hypertension, taking Viagra and other ED medication – such as Stendra, Cialis, and Levitra – is safe, effective, and appropriate.
Statins and ED Drugs
Generally speaking, it is OK to take ED drugs like Viagra or Cialis while on statin therapy. There are no known interactions, but this doesn't mean that everyone on statin drugs can take them.
Alpha blockers
Like both sildenafil and nitrates, these medications work by relaxing blood vessels. Combining alpha blockers with sildenafil can cause low blood pressure. So, if you're already taking an alpha blocker, your healthcare provider may have you take a lower sildenafil dose.
Viagra helps stimulate erections by increasing levels of cGMP -- which is also involved in blood clotting. Therefore, by increasing levels of cGMP, Viagra may actually increase the risk of blood clots, according to the researchers.
Why You're Not Getting All the Way Hard. Erectile dysfunction's mechanism is quite simple, but the underlying cause could be a myriad of reasons, from poor diet and exercise habits, diabetes or heart disease, to low self-esteem, depression or anxiety.
Do not take it more than once a day. The dose can be increased to 100mg or decreased to 25mg depending on its effect. Take sildenafil up to 4 hours before you want to have sex. For sildenafil to work properly, you'll need to be sexually excited.
Typically, an average erection may last from a few minutes to roughly half an hour. However, this can vary significantly due to the many factors that can affect erection duration. It is also worth noting that a person does not need an erection to achieve orgasm.
The concentration of Viagra in the blood peaks around 30–120 minutes after taking the drug — usually around the 60 minute mark.
We show that chronically inhibiting cGMP hydrolysis with the phosphodiesterase-5 inhibitor sildenafil improves energy balance and enhances in vivo insulin action in a mouse model of diet-induced insulin resistance.
Generally, there are three doses of sildenafil that are prescribed: 25mg, 50mg and 100mg. Your healthcare provider will assess which dose is right for you. Oh, and you should never take more than a single dose at once. Not only can this increase side effects, it can lead to a condition called priapism.