FULL PRESCRIBING INFORMATION: CONTENTS*
If you get your information about sildenafil from Super Bowl commercials or e-mail spam, you might dismiss it as a lifestyle drug of little real medical importance. In fact, it's a serious prescription medication that has helped millions of men who are distressed by an entirely legitimate medical problem.
| Dosage | Recommended Use | Onset of Action | Duration of Effect | Typical Frequency |
|---|---|---|---|---|
| 10 mg | Mild to moderate ED cases | 30-60 minutes | Up to 4-6 hours | Once per day, as needed |
| 20 mg | Moderate to severe ED | 30-60 minutes | Up to 4-6 hours | Once per day, as needed |
| 5 mg | For elderly or sensitive users | 30-60 minutes | Up to 4 hours | Once per day, as needed |
Because the drug acts on arteries beyond the penis, it can produce various side effects. That means it should only be prescribed by a personal physician who really knows you.
Frequently asked questions
At present, the concern is not great enough to prevent men from using these pills, but all men should use them carefully and responsibly. The most important worry about ED pills is their ability to widen arteries enough to lower blood pressure. It's rarely a problem in healthy men, but it explains a crucial precaution that applies to all three medications. Nitrates are medications that temporarily widen arteries by increasing their supply of nitric oxide. That's how they widen partially blocked coronary arteries in patients with angina.
Common Adverse Effects
But because the nitrates and ED pills all act on nitric oxide, they do not mix. Men who are taking nitrates should never use any of the ED pills. This ban includes all preparations of nitroglycerin (short-acting, under-the-tongue tablets or sprays); long-acting nitrates (isosorbide dinitrate, or Isordil, Sorbitrate, and others, and isosorbide mononitrate, Imdur, ISMO, and others); nitroglycerin patches and pastes; and amyl nitrite (so-called poppers, used for sexual stimulation by some men). ED pills are quite safe for men with stable cardiovascular disease who do not take nitrates. This group includes patients with stable angina, previous heart attacks, mild congestive heart failure, well-controlled hypertension, and previous strokes.
Why Would Someone Consider Using Both?
But men with recent heart attacks and strokes should wait until they have recovered fully, and patients with unstable blood pressure, active angina, or any other complex or unusual problem should hold off and get specific medical guidance. And men who take alpha blockers (particularly terazosin, or Hytrin, and doxazosin, or Cardura) for hypertension or benign prostatic hyperplasia (BPH) should use ED pills (particularly vardenafil or tadalafil) with great caution, if at all. Studies also suggest that sildenafil may increase respiratory distress in men with severe sleep apnea and that it slows gallbladder function, which might increase the risk of gallstones. Scientists who noticed that the ED pills can produce side effects in many parts of the body are asking if they can also serve therapeutic roles beyond male (or female) sexuality. Because of its seniority, most of the research has used sildenafil, so it's not clear if the newer medications will fill similar roles. And it also means that scientists are investigating uses for the drug in patients with an array of vascular disorders having nothing to do with sexual function. They have nearly identical effects on ED as well as similar side effects. Because they are newer drugs, scientists are just beginning to study them for problems that don't involve sexuality.
- Sildenafil 10mg is available by prescription only.
- Do not exceed the recommended dose to prevent adverse effects.
- Alcohol consumption can increase side effects of sildenafil.
- Sildenafil 10mg may interact with certain medications.
- Patients with heart issues should consult a doctor before use.
Sildenafil has already been licensed to treat men and women with pulmonary hypertension.
| Parameter | Value | Notes |
|---|---|---|
| Absorption Rate | Rapid | Peak plasma levels in ~60 minutes |
| Bioavailability | Approximately 40% | Due to first-pass metabolism |
| Half-life | About 4 hours | Time to reduce plasma concentration by half |
| Metabolism | Liver (primarily via CYP3A4) | Enzymatic breakdown |
| Excretion | Mainly feces (~80%) | Some via urine (~13%) |
Time will tell if any of these drugs will fill other potentials beyond promoting potency.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 200mg | 270 + 10 Pills | 379.76€ 361.68€ | |
| Kamagra Soft Tabs | 100mg | 20 Pills | 79.79€ 75.99€ | |
| Viagra Generic | 150mg | 90 + 6 Pills | 147.18€ 140.17€ | |
| Kamagra Polo | 100mg | 120 + 6 Pills | 327.15€ 311.57€ | |
| Viagra Generic | 150mg | 360 + 10 Pills | 423.48€ 403.31€ | |
| Viagra Generic | 25mg | 360 + 10 Pills | 213.68€ 203.50€ | |
| Viagra Generic | 200mg | 10 Pills | 40.96€ 39.01€ | |
| Viagra Generic | 200mg | 30 + 2 Pills | 83.07€ 79.11€ | |
| Viagra Generic | 150mg | 60 + 4 Pills | 111.25€ 105.95€ | |
| Viagra Generic | 100mg | 120 + 6 Pills | 149.50€ 142.38€ | |
| Viagra Generic | 200mg | 60 + 4 Pills | 125.19€ 119.23€ | |
| Viagra Generic | 150mg | 270 + 10 Pills | 326.61€ 311.06€ | |
| Viagra Generic | 150mg | 120 + 8 Pills | 177.58€ 169.12€ | |
| Kamagra Soft Tabs | 100mg | 272 + 12 Pills | 593.42€ 565.16€ | |
| Kamagra Polo | 100mg | 180 + 8 Pills | 446.52€ 425.26€ | |
| Viagra Generic | 200mg | 360 + 10 Pills | 481.98€ 459.03€ | |
| Viagra Generic | 100mg | 60 + 4 Pills | 96.36€ 91.77€ |
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
Liver Dose Adjustments
But for sildenafil, at least, some new uses appear promising. It's the only nonsexual condition that has earned FDA approval for sildenafil. But since it's a serious problem, any benefit is most welcome. When we think of blood pressure, we usually think of the systemic circulation, of the blood pumped from the heart's left ventricle to the aorta and then to the smaller arteries that carry oxygen-rich blood throughout the body. But to pick up vital oxygen, blood must first pass from the less powerful right ventricle through the pulmonary artery to the lungs, then back to the left side of the heart.
How much do Tadalafil and Sildenafil cost?
The pressures in the pulmonary artery are much lower (about 20/10 millimeters of mercury, or mm Hg) than in the aorta (lower than 120/80 mm Hg is considered healthy). Exercise is the most common cause of rising pulmonary artery pressure, but the elevation is mild and subsides promptly with rest. High altitudes are another cause, which can lead to mountain sickness (see below). Far more serious are the large number of lung diseases, vascular diseases, heart disorders, and miscellaneous conditions that can cause pulmonary hypertension. And in primary pulmonary hypertension, no underlying cause is evident.
How does Tadalafil help with these illnesses?
Pulmonary hypertension causes shortness of breath, first during exertion but eventually at rest if the condition progresses. A variety of treatments are available, depending on the underlying problem. And the FDA has approved sildenafil (Revatio) in a dose of 20 mg three times a day for men and women with pulmonary hypertension. Clinical trials have demonstrated improved exercise tolerance with few side effects. Pulmonary hypertension is a feature of acute mountain sickness. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
Dosages of Sildenafil
But a 2005 study of 16 patients with severe Raynaud's phenomenon that had not responded to other medications reported benefit from sildenafil in a dose of 50 mg twice a day. And a 2006 study of 40 Raynaud's patients reported similar benefits from vardenafil in a dose of 10 mg twice a day. Sildenafil was discovered by scientists looking for a new medication to dilate coronary arteries. It does that, but because it widens healthy coronary arteries more than diseased vessels, it has not been successful in treating angina. But it may have other benefits for cardiac patients.
How do the side effects compare for vardenafil and sildenafil?
In the first years of the Viagra era, research on sildenafil and the heart was devoted to making sure the drug was safe for the circulation. In most men with heart disease, it is. But several studies of patients with congestive heart failure also reported that the medication improves oxygen consumption, pulmonary artery pressure, and exercise capacity in these patients. Research shows that sildenafil helps the heart muscle relax properly, which could help patients with heart failure due to diastolic dysfunction. Another interesting property is sildenafil's ability to protect the heart from excessive stimulation by adrenaline.
Advantages Over Taking Both Pills Separately
Clinical trials will be needed to see which patients might benefit. It's the most speculative use for sildenafil, and it's far from clinical application. Still, it's an interesting area of new research. A European study of 25 men who had erectile dysfunction but no other circulatory disorders found that blood vessels in the brain responded to stress better after a 50-mg dose of sildenafil. More interesting results were reported by scientists in Michigan, who produced ischemic strokes in rats by temporarily blocking blood vessels. The proper dosage for sildenafil (Viagra) will vary between 25mg and 100mg once daily, with the most prescribed dosage being 50mg. Patients generally start with a lower dosage of 25mg to 50mg and depending on how the starting dosage works including how well it interacts with the body, may move to a higher dosage for a better experience.
Conclusion: The Right Treatment for You, With Expert Guidance
High altitudes produce low blood-oxygen levels. In turn, low oxygen produces a narrowing of sildenafil 100g the pulmonary arteries. The heart must therefore work harder, reducing the capacity to exercise. To find out if it might improve exercise capacity in low oxygen conditions, scientists tested 14 healthy mountain climbers in a lab in Germany and again at a Mount Everest base camp. In the lab, the volunteers breathed 10% oxygen through a mask; on the mountain, they breathed natural air.
What should I tell my healthcare provider before taking sildenafil?
Under both conditions, a 50-mg sildenafil tablet decreased pressures in the lungs' blood vessels and increased the maximum exercise capacity. It's a small study, and it's too soon to say if sildenafil will help prevent or treat acute mountain sickness. Still, a study of 29 climbers reported that tadalafil can also reduce pulmonary artery pressure at a high altitude. In affected individuals, exposure to the cold triggers spasm of the small arteries that supply blood to the fingers, toes, or both. Temporarily deprived of adequate blood flow, the involved digits become pale, cold, and very painful.
How is sildenafil supplied (dosage forms)?
It's a common condition, affecting up to 8% of men and 17% of women. In the vast majority, there are no underlying diseases (primary Raynaud's), and patients do well simply by minimizing their exposure to cold. But secondary Raynaud's can complicate collagen-vascular diseases or certain other conditions. It's not common, but secondary Raynaud's can be very painful and difficult to treat. Many medications have been used without consistent success. (1) For treating erectile dysfunction (or ED), sildenafil is normally only taken on an as needed basis, 30-60 minutes before sexual activity but can be dosed between 30 minutes and 4 hours before sexual activity. Sildenafil treats erectile dysfunction by selectively inhibiting an enzyme known as phosphodiesterase type 5, which allows corpus cavernosum smooth muscle to relax, making erections during sexual stimulation more satisfactory.
- Medication effectiveness can be impacted by certain health conditions.
- Men should not use sildenafil if they have a history of stroke.
- Sildenafil 10mg can sometimes cause nasal congestion.
- It’s important to report any unusual side effects to your doctor.
- Do not use sildenafil if you are taking other ED medications.
(2) An erection is achieved in a response cycle that begins with sildenafil producing arteriolar dilatation and increased blood flow to the erectile tissue of the penis.
What Are Side Effects Associated with Using Sildenafil?
During their sildenafil white recovery, the animals were divided into three groups. One received no treatment, another low-dose sildenafil, and the third high-dose sildenafil. The animals who got sildenafil recovered better, with the highest doses producing the best results. The scientists concluded that the medication actually stimulated the growth of new nerve cells in the brain tissue next to the stroke damage. It's far too early to know whether sildenafil may someday help people with strokes.