Label: SILDENAFIL- sildenafil citrate injection, solution

It inhibits the enzyme conversion that produces the contraction of the smooth muscle of the corpus cavernosum, allowing engorgement to be maintained. Medical Letter consultants reviewed the data on this drug. Plasma concentrations of sildenafil reach a peak in about one hour.

Comparing Drug Interactions

Read on to learn more about how they work, their effectiveness and how much you can expect to pay for each. Both vardenafil and sildenafil are PDE5 inhibitors with overlapping side effects like headache, flushing, nasal congestion and heartburn. Vardenafil is a bit less likely to cause visual color tinge or drop blood pressure than sildenafil, but individual experience varies. Sildenafil kicks in within approximately 30 minutes and lasts about four hours. Vardenafil starts closer to 60 minutes and lasts five to seven hours.

What conditions is Tadalafil approved to treat?

Vardenafil (Levitra®) is a medication prescribed to treat erectile dysfunction in men. It belongs to a class of medications called phosphodiesterase (PDE) inhibitors and works by increasing blood flow to the penis during sexual stimulation. While vardenafil does not cure erectile dysfunction or increase sexual desire, the increased blood flow to the genitals can cause an erection. Vardenafil comes as a rapidly disintegrating oral tablet.2 Recommendations are to take as needed, 60 minutes before sexual activity. The most commonly prescribed dosage is 10 mg once per day as needed.3 Depending on your personal needs and direction from your medical provider, you may be prescribed 5 mg or 20 mg doses.

Still not finding the right product?

The effects of vardenafil can last anywhere from five to seven hours.4 Vardenafil usually should not be taken more than once every 24 hours. Sildenafil (Viagra®) is a medication used to treat erectile dysfunction in men. Sildenafil is in a class of medications called phosphodiesterase (PDE) inhibitors which treat erectile dysfunction by increasing blood flow to the penis during sexual stimulation. This increased blood flow can lead to an erection. However, sildenafil cannot cure erectile dysfunction or increase sexual desire. A fatty meal delays the peak by about one hour and decreases the peak concentration without affecting total absorption. The drug is actively metabolized in the liver and is excreted largely as metabolites in the stool.

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%)

Both the parent drug and the active metabolite have a half-life of about four hours.

Product	Dosage	Quantity + Bonus	Price
Kamagra	100mg	120 + 6 Pills	330.74€ 314.99€	Buy
Kamagra Soft Tabs	100mg	180 + 8 Pills	425.45€ 405.19€	Buy
Viagra Generic	100mg	30 + 4 Pills	60.91€ 58.01€	Buy
Kamagra Polo	100mg	180 + 8 Pills	446.52€ 425.26€	Buy
Viagra Generic	50mg	10 Pills	26.87€ 25.59€	Buy
Viagra Generic	200mg	180 + 10 Pills	277.56€ 264.34€	Buy
Viagra Generic	200mg	60 + 4 Pills	125.19€ 119.23€	Buy
Kamagra Soft Tabs	100mg	12 Pills	57.55€ 54.81€	Buy
Kamagra Polo	100mg	60 + 4 Pills	189.39€ 180.37€	Buy
Viagra Generic	200mg	120 + 8 Pills	204.80€ 195.05€	Buy
Viagra Generic	50mg	180 + 8 Pills	158.82€ 151.26€	Buy
Kamagra Oral Jelly	100mg	10 Sachets	54.55€ 51.95€	Buy

In men older than 65 years and in men with hepatic or severe renal insufficiency, clearance is slower. Only one published study of sildenafil using objective measurements has been conducted.

Comparing Which Works Faster

Sildenafil is also prescribed to treat pulmonary arterial hypertension.6 For most patients, the recommended dosage is 50 mg approximately one hour before sexual activity. However, sildenafil can be taken anywhere from 30 minutes to four hours before sexual activity.7 Your medical provider may prescribe a different dosage, depending on your needs, of 20 mg, 25 mg or 100 mg. The effects of sildenafil last approximately four hours.8 Vardenafil and sildenafil are similarly effective at treating erectile dysfunction. Both are phosphodiesterase inhibitors; however, vardenafil has been shown to be more potent and more selective than sildenafil at inhibiting phosphodiesterase-5. Vardenafil does not inhibit phosphodiesterase-6, which has been connected to a rare side effect of sildenafil of altered color perception.9 Sildenafil also acts faster than vardenafil, kicking in as soon as 30 minutes.

How Sildenafil Works to Treat ED

Vardenafil is effective closer to 60 minutes after ingestion.10 Vardenafil has been shown in studies to be effective for erectile dysfunction in 71% of men under the age of 45, 76% of men aged 45-64 and 85% of men over 65.11 Up to 87% of men in one study with a broad spectrum of participants reported sildenafil had improved their erections compared with 11.3%-41.3% of patients in subgroups receiving a placebo.12 Common side effects of vardenafil include:13 Sildenafil has many of the same side effects as vardenafil like headache, flushing, nasal congestion and nausea/upset stomach. A few side effects that sildenafil has that aren’t common with vardenafil include:14 Numbness, burning or tingling in the arms, hands, feet or legs. Numbness, burning or tingling in the arms, hands, feet or legs. Pain in muscles, back, arms or legs. Changes in color vision (seeing a blue tinge on objects or having difficulty telling the difference between blue and green).

What should I do if I accidentally use too much sildenafil?

Get secure, private treatment online from RedBox Rx with FDA-approved meds starting at $1 per pill. Negative interactions may occur if the following drugs or substances are consumed while taking vardenafil15 or sildenafil:16 It is not advised to take vardenafil and sildenafil together, as it may cause blood pressure to fall excessively. Additionally, there would be an increased risk of other side effects such as dizziness, lightheadedness, fainting, headache, flushing, heart palpitations and priapism (prolonged and painful erection unrelated to sexual activity).17 The average cost of vardenafil is $30 for two tablets.18 With RedBox Rx, you can get generic vardenafil for as low as $3 per tablet. The average cost of sildenafil is approximately $10 for two tablets.19 With RedBox Rx, you can get generic sildenafil for $5 and as low as $1 per tablet when choosing larger quantities. You can also see how RedBox Rx compares to other online pharmacies in the chart below. Plethysmographic measurements were obtained in 12 men with erectile dysfunction in a randomized, controlled crossover study. The mean duration of erections was about one minute with placebo, four minutes with 10 mg of sildenafil, about eight minutes with 25 mg and eight to 11 minutes with 50 mg of active drug.

• Sildenafil 10mg may be more suitable for older adults with sensitivity.
• Do not take more than one dose in 24 hours.
• Do not mix sildenafil with recreational drugs like poppers.
• Be aware that certain foods and medications can influence its effects.
• Regular medical check-ups are recommended when using sildenafil regularly.

The men were instructed to record erectile activity after taking 25 mg of sildenafil or placebo once daily for seven days. The number of erections within two hours after taking sildenafil was about five times greater with the active drug than with placebo. Other unpublished studies evaluated men with erectile dysfunction who took 25, 50 or 100 mg of sildenafil or placebo at home for up to six months.

Proper Use

Start your treatment today with our ED assessment and free online consultation. Sildenafil is the first oral drug approved by the U.S. Food and Drug Administration for treatment of erectile dysfunction. Although other drugs have been on the market for some time, they have met with mixed success because of the need for injection or insertion into the urethra. Sildenafil enhances the physiologic response that causes penile erection after sexual arousal. The drug did not affect the frequency of attempted intercourse. However, in four fixed-dose trials, improvement in erections was reported by 63 percent of the 214 men taking 25 mg of sildenafil, 74 percent of the 391 men taking 50 mg and 82 percent of the 380 men taking 100 mg of the drug.

5.3 Epistaxis

D., & Wicker, P. A. Oral sildenafil in the treatment of erectile dysfunction. The New England Journal of Medicine, 338(20), 1397–1404. A prospective study of the beneficial effects of dose optimization and customized instructions on patient satisfaction with sildenafil citrate (Viagra) for erectile dysfunction.

Dosage Forms & Strengths

International Journal of Impotence Research, 18(5), 389–394. Sublingual sildenafil in the treatment of erectile dysfunction: Faster onset of action with less dose. International Journal of Urology, 11(11), 989–993. Sex, erectile dysfunction, and the heart: A growing problem. Phosphodiesterase‑5 (PDE5) inhibitors in the management of erectile dysfunction.

Using a mail-order pharmacy

Pharmacy and Therapeutics, 38(7), 407–419. Cardiovascular effects of sildenafil citrate and recommendations for its use. American Journal of Cardiology, 84(5), 11N–17N. Erectile dysfunction (ED) is a common condition affecting around 40% of men at age 40 and 70% at age 70.1 While you may feel some embarrassment, know that you are not alone and there are effective medications available to you from the privacy of your own home. Vardenafil (Levitra®) and sildenafil (Viagra®) are two commonly prescribed prescription medications for ED. Twenty-four percent of the 463 men taking placebo experienced improvement in erectile functioning. The effect was detectable as soon as 30 minutes after taking the drug and lasted up to four hours.

Side Effect	Severity	Likelihood	Management Tips
Headache	Mild to moderate	Common	Mild analgesics, hydration
Flushing	Mild	Common	Cool environment, stay hydrated
Nasal congestion	Mild	Moderately common	Decongestants if necessary
Dizziness	Mild	Possible	Avoid sudden movements
Visual disturbances	Mild	Rare	Rest and monitor if occurs

Some men also reported increased erectile functioning the next day.

• Sildenafil 10mg can cause dizziness or vision changes in some users.
• Always check for drug interactions before taking sildenafil.
• It is important to stay hydrated when using sildenafil.
• The medication is not effective as an aphrodisiac without stimulation.
• Seek emergency help if you experience chest pain after use.

Forty-three percent of men with radical prostatectomy reported improvement in erections after taking sildenafil compared with 15 percent after taking placebo. Sildenafil lowers blood pressure slightly in normal patients and substantially in patients who are undergoing nitrate therapy for angina. The most common side effects are headache, flushing and dyspepsia. Transient abnormal vision, usually a color tinge or increased sensitivity to light, is uncommon and is usually dose-related. No incidence of priapism has been reported. Sildenafil should be used cautiously in patients taking cimetidine, erythromycin, rifampin and ketoconazole.

Condition	Risk Factors	Recommendations
Use with nitrates	Severe hypotension, risk of significant blood pressure drop	Avoid combining, consult healthcare provider
Severe cardiovascular disease	Risk of adverse cardiovascular events	Use only under medical supervision
Liver impairment	Altered metabolism, increased side effects	Dose adjustment or avoid use
Retinitis pigmentosa	Potential for increased visual side effects	Use with caution, consult ophthalmologist

Sildenafil is available in 25-, 50- and 100-mg tablets. The manufacturer recommends an initial dosage of 50 mg (which can be increased to 100 mg if necessary) taken one hour before intercourse.

Frequently asked questions

*Discounts for larger quantities as low as $1.00 per tablet. Both vardenafil20 and sildenafil21 sildenafil 50g require a prescription. You can obtain a prescription online for vardenafil and sildenafil. You cannot get vardenafil or sildenafil over the counter. Additionally, the FDA warns against purchasing over-the-counter vardenafil and sildenafil alternatives because they are not regulated and pose health risks like dangerously low blood pressure.22 RedBox Rx only prescribes FDA-approved medications for ED.

How is sildenafil supplied (dosage forms)?

RedBox Rx makes obtaining a prescription for ED, like vardenafil or sildenafil, easy and affordable. Transparent, affordable, flat rates for ED medications starting at $1 per tablet. Free consultations with a U.S. licensed medical professional. No office wait times or scheduling issues typical with physical medical practices. Patients older than 65 years of age, those with hepatic or renal dysfunction and those who are taking a CYP3A4 inhibitor should start with a 25-mg dosage.