After 12 weeks of treatment in the dose-escalation study, the proportions of men taking 25, 50, or 100 mg of sildenafil were 2 percent (4 men), 23 percent (38 men), and 74 percent (121 men), respectively. For the men taking placebo, the corresponding proportions were 0 percent, 5 percent (8 men), and 95 percent (158 men). Two hundred twenty-five men who completed the 12-week study were enrolled to receive open-label sildenafil for an additional 32 weeks. In the dose–response study, increasing doses of sildenafil were associated with higher mean scores for the questions of the International Index of Erectile Function assessing frequency of penetration (question 3) and maintenance of erections after sexual penetration (question 4) (P<0.001) (Table 2). The mean scores for these questions did not vary according to the cause of erectile dysfunction. For question 3, the percentage increases in mean score from base line to the end of treatment were 60, 84, and 100 percent for the men who received 25, 50, and 100 mg of sildenafil, respectively, as compared with an increase of 5 percent for the men who received placebo. For question 4, the corresponding values were 121, 133, and 130 percent for the men who received 25, 50, and 100 mg of sildenafil, respectively, as compared with 24 percent for those who received placebo. In the dose-escalation study, the mean scores for questions 3 and 4 of the International Index were significantly higher after treatment for the sildenafil group than for the placebo group (P<0.001) (Table 2). The percent increase from base line was 95 percent for question 3 and 140 percent for question 4 for the men taking sildenafil, as compared with 10 percent and 13 percent, respectively, for those taking placebo.
- Sildenafil tablets are used to treat erectile dysfunction by improving blood flow to the penis.
- Common dosages of sildenafil tablets include 25mg, 50mg, and 100mg.
- Always follow a healthcare provider’s instructions when taking sildenafil tablets.
The mean scores for the erectile-function domain on the International Index increased with increasing doses of sildenafil in the dose–response study (P< 0.001). The mean score for the erectile-function domain in the dose-escalation study was significantly higher sildenafil otc for the men taking sildenafil (22.1) than for those taking placebo (12.2, P<0.001) (Figure 1A). The mean scores for the orgasmic-function, intercourse-satisfaction, and overall-satisfaction domains were also significantly higher in the sildenafil group (P<0.001) (Figure 1B), whereas the mean scores for sexual desire were not significantly different in the two groups (P = 0.13). The event-log data on the proportion of men achieving erections hard enough for sexual intercourse (i.e., grade 3 or 4) during the last four weeks of treatment showed a significant dose–response relation for sildenafil (72 percent, 80 percent, and 85 percent for doses of 25 mg, 50 mg, and 100 mg, respectively, as compared with 50 percent for placebo; P<0.001).
Mechanism of action
After 12 weeks of treatment in the dose-escalation study, the proportions of men taking 25, 50, or 100 mg of sildenafil were 2 percent (4 men), 23 percent (38 men), and 74 percent (121 men), respectively. For the men taking placebo, the corresponding proportions were 0 percent, 5 percent (8 men), and 95 percent (158 men). Two hundred twenty-five men who completed the 12-week study were enrolled to receive open-label sildenafil for an additional 32 weeks. In the dose–response study, increasing doses of sildenafil were associated with higher mean scores for the questions of the International Index of Erectile Function assessing frequency of penetration (question 3) and maintenance of erections after sexual penetration (question 4) (P<0.001) (Table 2). The mean scores for these questions did not vary according to the cause of erectile dysfunction.
Who should not take sildenafil?
For question 3, the percentage increases in mean score from base line to the end of treatment were 60, 84, and 100 percent for the men who received 25, 50, and 100 mg of sildenafil, respectively, as compared with an increase of 5 percent for the men who received placebo. For question 4, the corresponding values were 121, 133, and 130 percent for the men who received 25, 50, and 100 mg of sildenafil, respectively, as compared with 24 percent for those who received placebo. In the dose-escalation study, the mean scores for questions 3 and 4 of the International Index were significantly higher after treatment for the sildenafil group than for the placebo group (P<0.001) (Table 2). The percent increase from base line was 95 percent for question 3 and 140 percent for question 4 for the men taking sildenafil, as compared with 10 percent and 13 percent, respectively, for those taking placebo. The mean scores for the erectile-function domain on the International Index increased with increasing doses of sildenafil in the dose–response study (P< 0.001).
#7 Vardenafil(Levitra)
The mean score for the erectile-function domain in the dose-escalation study was significantly higher sildenafil otc for the men taking sildenafil (22.1) than for those taking placebo (12.2, P<0.001) (Figure 1A). The mean scores for the orgasmic-function, intercourse-satisfaction, and overall-satisfaction domains were also significantly higher in the sildenafil group (P<0.001) (Figure 1B), whereas the mean scores for sexual desire were not significantly different in the two groups (P = 0.13). The event-log data on the proportion of men achieving erections hard enough for sexual intercourse (i.e., grade 3 or 4) during the last four weeks of treatment showed a significant dose–response relation for sildenafil (72 percent, 80 percent, and 85 percent for doses of 25 mg, 50 mg, and 100 mg, respectively, as compared with 50 percent for placebo; P<0.001). The mean number of grade 3 and grade 4 erections and the mean number of grade 4 erections during the last four weeks of treatment were also significantly higher in the sildenafil group (P< 0.001) (Figure 2A), with 80 percent of the grade 3 erections and 94 percent of the grade 4 erections resulting in successful sexual intercourse. In the dose-escalation study, 69 percent of all attempts at sexual intercourse by the men receiving sildenafil were successful in the last four weeks of treatment, as compared with 22 percent for those receiving placebo (P<0.001) (Figure 2B). The mean number of grade 3 and grade 4 erections and the mean number of grade 4 erections during the last four weeks of treatment were also significantly higher in the sildenafil group (P< 0.001) (Figure 2A), with 80 percent of the grade 3 erections and 94 percent of the grade 4 erections resulting in successful sexual intercourse. In the dose-escalation study, 69 percent of all attempts at sexual intercourse by the men receiving sildenafil were successful in the last four weeks of treatment, as compared with 22 percent for those receiving placebo (P<0.001) (Figure 2B).
| Dose (mg) | Typical Usage Frequency | Onset of Action | Duration of Effect |
|---|---|---|---|
| 25 | As needed, 1 time/day | 30-60 minutes | Up to 4 hours |
| 50 | As needed, 1-2 times/day | 30-60 minutes | Up to 6 hours |
| 100 | As needed, 1 time/day | 30-60 minutes | Up to 4-6 hours |
During the last four weeks of treatment, the mean numbers of attempts at sexual intercourse that were successful were 5.9 for men in the sildenafil group and 1.5 for men in the placebo group (P<0.001) (Figure 2B).
| Interacting Drug / Substance | Effect | Clinical Advice |
|---|---|---|
| Nitrates | Severe hypotension | Do not combine |
| Alpha-blockers | Possible hypotension | Use with caution |
| CYP3A4 inhibitors (e.g., ketoconazole) | Increased sildenafil levels | Adjust dosage accordingly |
After 24 weeks of treatment in the dose–response study, improved erections were reported by 56, 77, and 84 percent of the men taking 25, 50, and 100 mg of sildenafil, respectively, as compared with 25 percent of those taking placebo (P<0.001 for treatment effect). After 12 weeks of treatment in the dose-escalation study, 101 of the 136 men in the sildenafil group who responded to the global-efficacy question (74 percent) reported improved erections, as compared with 23 of the 118 men in the placebo group who responded to the question (19 percent, P<0.001). During the dose–response study, 31 of the 316 men in the sildenafil group (10 percent) and 36 of the 216 men in the placebo group (17 percent) discontinued treatment (Table 3). Four men (1 percent) in the sildenafil group stopped taking the drug because of treatment-related adverse effects (nausea and vomiting in one, leg pain and backache in one, intermittent headache and dyspepsia in one, and headache in one), as compared with one man (<1 percent) who stopped taking placebo (because of headache and nausea). Five men (2 percent) in the sildenafil group and 11 men (5 percent) in the placebo group discontinued treatment because of insufficient responses. In the dose-escalation study, 9 men (6 percent) stopped taking sildenafil and 13 men (8 percent) stopped taking placebo. One man stopped taking sildenafil because of treatment-related headache and flushing, and one man stopped because of an insufficient response. Laboratory-test results indicated no evidence of sildenafil-induced abnormalities. The most frequently reported adverse effects of sildenafil in the two studies were transient headache, flushing, dyspepsia, and rhinitis (Table 3). Transient visual disturbances (i.e., changes in the perception of color hue or brightness) were reported by some men.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Kamagra Soft Tabs | 100mg | 32 Pills | 120.11€ 114.39€ | |
| Kamagra Polo | 100mg | 20 Pills | 83.56€ 79.58€ | |
| Kamagra | 100mg | 180 + 6 Pills | 436.79€ 415.99€ | |
| Viagra Generic | 100mg | 20 Pills | 45.58€ 43.41€ | |
| Kamagra | 100mg | 84 + 6 Pills | 264.44€ 251.85€ | |
| Kamagra Polo | 100mg | 120 + 6 Pills | 327.15€ 311.57€ | |
| Viagra Generic | 25mg | 60 + 4 Pills | 71.99€ 68.56€ | |
| Kamagra Oral Jelly | 100mg | 30 + 5 Sachets | 136.20€ 129.71€ | |
| Viagra Generic | 25mg | 20 Pills | 37.74€ 35.94€ | |
| Viagra Generic | 50mg | 90 + 6 Pills | 107.37€ 102.26€ | |
| Kamagra | 100mg | 60 + 4 Pills | 201.34€ 191.75€ | |
| Viagra Generic | 150mg | 20 Pills | 55.02€ 52.40€ | |
| Viagra Generic | 150mg | 180 + 10 Pills | 236.46€ 225.20€ | |
| Viagra Generic | 100mg | 360 + 10 Pills | 330.21€ 314.49€ | |
| Kamagra Polo | 100mg | 60 + 4 Pills | 189.39€ 180.37€ | |
| Viagra Generic | 200mg | 180 + 10 Pills | 277.56€ 264.34€ |
The frequency of these adverse effects increased with increasing doses of sildenafil, but the symptoms were usually mild and lasted a few minutes to a few hours after dosing. No man reported priapism during the studies.
5.6 Combination with other PDE-5 Inhibitors
Burnett, Baltimore; R. Castellanos, Fort Myers, Fla.; L. Of the 225 men enrolled in the open-label extension study, 207 (92 percent) completed an additional 32 weeks of sildenafil treatment. Four men (2 percent) withdrew because of treatment-related adverse effects (headache in two, intermittent flushing and blurred vision in one, and groin pain and headache in one). We found that sildenafil improves sexual function in men with erectile dysfunction. In keeping with sildenafil's mode of action (i.e., the drug causes erection only in response to sexual stimulation), the studies were performed entirely in a natural environment, which meant that we had to rely on the men's own reports of efficacy. However, the self-administered International Index of Erectile Function has a high degree of sensitivity and specificity for detecting treatment-related changes in men with erectile dysfunction.13 This questionnaire, together with the global-efficacy question, provided a comprehensive assessment of erectile function during a specified recall period (four weeks), and the event log provided information about individual events during treatment. The men's partners were questioned sildenafil tablets 125 in each of the studies, and although the results corroborated the men's efficacy assessments, only 25 percent of the partners completed the optional questionnaire. Recognizing the fact that in most men erectile dysfunction is a multifactorial problem, we enrolled men with a broad variety of causes of erectile dysfunction. The identification of an organic abnormality does not establish it as the cause of erectile dysfunction.14 Conversely, failure to identify an organic cause does not prove a psychogenic origin. In the dose–response study, increasing doses of sildenafil (25 to 100 mg) were increasingly effective in improving the frequency of penetration and the maintenance of erections after penetration, the mean score for the erectile-function domain of the International Index, and the percentage of men reporting better erections.
8.1 Pregnancy
During the last four weeks of treatment, the mean numbers of attempts at sexual intercourse that were successful were 5.9 for men in the sildenafil group and 1.5 for men in the placebo group (P<0.001) (Figure 2B). After 24 weeks of treatment in the dose–response study, improved erections were reported by 56, 77, and 84 percent of the men taking 25, 50, and 100 mg of sildenafil, respectively, as compared with 25 percent of those taking placebo (P<0.001 for treatment effect). After 12 weeks of treatment in the dose-escalation study, 101 of the 136 men in the sildenafil group who responded to the global-efficacy question (74 percent) reported improved erections, as compared with 23 of the 118 men in the placebo group who responded to the question (19 percent, P<0.001). During the dose–response study, 31 of the 316 men in the sildenafil group (10 percent) and 36 of the 216 men in the placebo group (17 percent) discontinued treatment (Table 3). Four men (1 percent) in the sildenafil group stopped taking the drug because of treatment-related adverse effects (nausea and vomiting in one, leg pain and backache in one, intermittent headache and dyspepsia in one, and headache in one), as compared with one man (<1 percent) who stopped taking placebo (because of headache and nausea).
How sildenafil is used
Five men (2 percent) in the sildenafil group and 11 men (5 percent) in the placebo group discontinued treatment because of insufficient responses. In the dose-escalation study, 9 men (6 percent) stopped taking sildenafil and 13 men (8 percent) stopped taking placebo. One man stopped taking sildenafil because of treatment-related headache and flushing, and one man stopped because of an insufficient response. Laboratory-test results indicated no evidence of sildenafil-induced abnormalities. The most frequently reported adverse effects of sildenafil in the two studies were transient headache, flushing, dyspepsia, and rhinitis (Table 3).
Revatio for Oral Suspension
Transient visual disturbances (i.e., changes in the perception of color hue or brightness) were reported by some men. The frequency of these adverse effects increased with increasing doses of sildenafil, but the symptoms were usually mild and lasted a few minutes to a few hours after dosing. No man reported priapism during the studies. Of the 225 men enrolled in the open-label extension study, 207 (92 percent) completed an additional 32 weeks of sildenafil treatment. Four men (2 percent) withdrew because of treatment-related adverse effects (headache in two, intermittent flushing and blurred vision in one, and groin pain and headache in one). In the dose-escalation study, sildenafil treatment was associated with improvements in the frequency of penetration and the maintenance of erections after penetration. The therapeutic response to sildenafil was similar in men with various causes of erectile dysfunction.
- Sildenafil is a PDE5 inhibitor specifically designed to treat erectile dysfunction.
- Use sildenafil tablets only as prescribed; do not share your medication.
- Contact your doctor if you notice an allergic reaction, such as swelling or rash.
The mean scores after sildenafil therapy approached those of normal men of the same age.
- Sildenafil tablets may interact with medications like alpha-blockers and certain antibiotics.
- Overdose symptoms include severe hypotension, headache, and visual disturbances.
- Always keep sildenafil tablets out of reach of children and pets.
The men we studied had a normal level of sexual desire, as might be expected of men with erectile dysfunction who enter a clinical trial,13 and sildenafil did not alter that level.
How should this medicine be used?
We found that sildenafil improves sexual function in men with erectile dysfunction. In keeping with sildenafil's mode of action (i.e., the drug causes erection only in response to sexual stimulation), the studies were performed entirely in a natural environment, which meant that we had to rely on the men's own reports of efficacy. However, the self-administered International Index of Erectile Function has a high degree of sensitivity and specificity for detecting treatment-related changes in men with erectile dysfunction.13 This questionnaire, together with the global-efficacy question, provided a comprehensive assessment of erectile function during a specified recall period (four weeks), and the event log provided information about individual events during treatment. The men's partners were questioned sildenafil tablets 125 in each of the studies, and although the results corroborated the men's efficacy assessments, only 25 percent of the partners completed the optional questionnaire. Recognizing the fact that in most men erectile dysfunction is a multifactorial problem, we enrolled men with a broad variety of causes of erectile dysfunction.
Pulmonary hypertension
The identification of an organic abnormality does not establish it as the cause of erectile dysfunction.14 Conversely, failure to identify an organic cause does not prove a psychogenic origin. In the dose–response study, increasing doses of sildenafil (25 to 100 mg) were increasingly effective in improving the frequency of penetration and the maintenance of erections after penetration, the mean score for the erectile-function domain of the International Index, and the percentage of men reporting better erections. In the dose-escalation study, sildenafil treatment was associated with improvements in the frequency of penetration and the maintenance of erections after penetration. The therapeutic response to sildenafil was similar in men with various causes of erectile dysfunction. The mean scores after sildenafil therapy approached those of normal men of the same age.
Professional resources
The men we studied had a normal level of sexual desire, as might be expected of men with erectile dysfunction who enter a clinical trial,13 and sildenafil did not alter that level. Successful sexual intercourse was therefore a key end point for these men. Overall, the results of the efficacy assessments demonstrated that sildenafil significantly improved erectile function and quadrupled the success of intercourse, with effectiveness maintained for at least six months. Its main adverse effects were headache, flushing, dyspepsia, and visual disturbances and were usually mild. Only one sildenafil chewable tablets man with a visual disturbance discontinued treatment, and he also had flushing. Successful sexual intercourse was therefore a key end point for these men. Overall, the results of the efficacy assessments demonstrated that sildenafil significantly improved erectile function and quadrupled the success of intercourse, with effectiveness maintained for at least six months. Its main adverse effects were headache, flushing, dyspepsia, and visual disturbances and were usually mild. Only one sildenafil chewable tablets man with a visual disturbance discontinued treatment, and he also had flushing. Few men discontinued sildenafil, suggesting a relatively high level of drug tolerability and acceptance. No man had priapism after sildenafil treatment. Sildenafil has modest vasodilator properties but no effect on heart rate. The American Urological Association Panel on the Treatment of Organic Erectile Dysfunction stated that the ultimate goal is a therapy that is reliable, has minimal side effects, and is simple to use.6 Sildenafil appears to meet these specifications. Oral therapy permits discreet administration and is less invasive than some other treatment options, including injections into the corpus cavernosum, transurethral drug delivery, and prosthesis implantation. Goldstein, Lue, Padma-Nathan, Rosen, and Steers have served as consultants to Pfizer, manufacturer of sildenafil, as well as to other companies making products for the treatment of erectile dysfunction. We are indebted to all the investigators who participated in the trials; to Dr. Ian Osterloh and Dr. David Cox of Pfizer for their help with the study design and logistics; to Dr.
What happens if I miss a dose?
Few men discontinued sildenafil, suggesting a relatively high level of drug tolerability and acceptance. No man had priapism after sildenafil treatment. Sildenafil has modest vasodilator properties but no effect on heart rate. The American Urological Association Panel on the Treatment of Organic Erectile Dysfunction stated that the ultimate goal is a therapy that is reliable, has minimal side effects, and is simple to use.6 Sildenafil appears to meet these specifications. Oral therapy permits discreet administration and is less invasive than some other treatment options, including injections into the corpus cavernosum, transurethral drug delivery, and prosthesis implantation.
Drugs Affecting Gastric Acidity
Goldstein, Lue, Padma-Nathan, Rosen, and Steers have served as consultants to Pfizer, manufacturer of sildenafil, as well as to other companies making products for the treatment of erectile dysfunction. We are indebted to all the investigators who participated in the trials; to Dr. Ian Osterloh and Dr. David Cox of Pfizer for their help with the study design and logistics; to Dr. Michael Collins and Dr.
Organic Nitrates, Nitrites, and Nitric Oxide Donors
Michael Smith of Pfizer for their assistance with data analysis; and to Dr. Patricia Leinen and Dr. Michael Sweeney for aid in the preparation of the manuscript. The other members of the Sildenafil Study Group are S. Auerbach, Newport Beach, Calif.; A.L. Michael Collins and Dr. Michael Smith of Pfizer for their assistance with data analysis; and to Dr. Patricia Leinen and Dr. Michael Sweeney for aid in the preparation of the manuscript. The other members of the Sildenafil Study Group are S. Auerbach, Newport Beach, Calif.; A.L. Burnett, Baltimore; R. Castellanos, Fort Myers, Fla.; L.
