Tolerance to sildenafil has been reported,[6] but so has efficacy for up to 4 years without requirement for dose increase. [7] It is possible that tolerance, if any, is due to progression in the organic pathology responsible for the ED.
Sildenafil is safe to take for a long time. There do not seem to be any lasting harmful effects from taking it for many months and years.
Sildenafil usually should not be taken more than once every 24 hours. If you have certain health conditions or are taking certain medications, your doctor may tell you to take sildenafil less often. You can take sildenafil with or without food.
If you take more than the recommended dose of Viagra, you can develop a condition known as priapism, which is an erection that lasts for longer than four hours. Priapism is a medical emergency and can result in serious damage to the delicate structures in your penis, so seek medical attention immediately.
However, according to the Food and Drug Administration (FDA), there have been reports of myocardial infarction (heart attack), stroke, irregular heartbeat (arrhythmias), and even death in people taking Viagra.
Sildenafil causes small decreases in systolic and diastolic blood pressures, but clinically significant hypotension is rare. Studies of sildenafil and nitrates taken together show much greater drops in blood pressure.
How long does Viagra last? 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.
In healthy volunteers, sildenafil doses are absorbed rapidly, with maximum plasma concentrations achieved within a median time of 1 h (range, 0.5–2 h) after dosing [3].
Viagra does not stimulate you sexually, it can only help you get an erection once you're already aroused. Because Viagra only helps you to get an erection by improving blood flow to the penis, it doesn't force you to get an erection, so it won't work unless you're sexually stimulated.
There are several reasons Viagra and other ED drugs might not work effectively as treatments for erectile dysfunction. These include using Viagra incorrectly, taking a low dose of Viagra and using Viagra to treat ED that's caused by something other than poor blood flow.
If Viagra is not working for you, it may be because your dosage is too low. The usual starting dose for Viagra is 50mg, but you may be started on a lower dose of 25mg if you take certain medications. The maximum dose of Viagra that you can take is 100mg. Your doctor can prescribe a higher dose if it is safe for you.
Sildenafil also interacts with alcohol, grapefruit juice, and medications that affect liver proteins. This can result in a worsening of side effects like dizziness, headaches, and flushing.
What happens if a woman takes Viagra? Just as Viagra helps improve blood flow for an erection, it may improve blood flow in the female reproductive parts. When this happens, it may cause more sensitivity and stimulation, causing the person taking it to become more aroused.
No interactions were found between aspirin and Viagra.
Is There a Way To Tell if a Man is Taking Viagra? Wondering if your man is taking a pill to keep up his energy in bed? You could check his medicine cabinet, send an email to his doctor asking what prescription drugs he's on, or have his blood tested.
The 'as required' Tadalafil (generic Cialis) has an advantage over Sildenafil in that it lasts a lot longer – up to 36 hours (compared with 4-5 hours for Sildenafil).
The biggest difference between Viagra and Cialis is the amount of time their effects last. Viagra remains effective for 4 to 6 hours, which offers ample opportunity to have sex on multiple occasions if you wish. However Cialis typically allows you to achieve erections for up to 36 hours after taking a tablet.
Erectile dysfunction (ED) medications that can be cut in half. The most common ED medications can be safely split. This includes: Sildenafil (Viagra)
You may be more likely to experience symptoms such as dizziness, lightheadedness, fainting, flushing, headache, and heart palpitations. You should avoid or limit the use of alcohol while being treated with sildenafil, and use caution when getting up from a sitting or lying position.
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.
Results In comparison to placebo, a single 50-mg dose of sildenafil significantly increased the percentage of total sleep time with an arterial oxygen saturation of less than 90% (mean ± SD, 14.2% ± 9.1% vs 8.5% ± 3.2%, P<. 01), without a difference in the nadir of oxygen desaturation.