Concurrent use is expected to substantially increase the sildenafil plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection.
5.4 Hearing Loss
Coadministration with sildenafil results in a 210% increase in sildenafil AUC. [29] If sildenafil is coadministered with amprenavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions. [27][30] Substantially increased sildenafil plasma concentrations may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) sildenafil 10mg inhibitors to patients receiving fosamprenavir. [29] If sildenafil is coadministered with fosamprenavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions.
Pulmonary hypertension
[27][29] Coadministration with sildenafil results in a 210% increase in sildenafil AUC. Substantially increased sildenafil plasma concentrations may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving atazanavir. [31] If sildenafil is coadministered with atazanavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions. [27][31] Coadministration of atazanavir with PDE5 inhibitors is expected to substantially increase their plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. Sildenafil is contraindicated for use with atazanavir; cobicistat when used for pulmonary arterial hypertension (PAH).
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 100mg | 120 + 6 Pills | 149.50€ 142.38€ | |
| Viagra Generic | 50mg | 60 + 4 Pills | 83.93€ 79.93€ | |
| Kamagra Soft Tabs | 100mg | 120 + 6 Pills | 311.78€ 296.93€ | |
| Kamagra Oral Jelly | 100mg | 30 + 5 Sachets | 136.20€ 129.71€ | |
| Kamagra Soft Tabs | 100mg | 20 Pills | 79.79€ 75.99€ | |
| Kamagra Soft Tabs | 100mg | 84 + 4 Pills | 233.05€ 221.95€ | |
| Kamagra Oral Jelly | 100mg | 21 Sachets | 95.92€ 91.35€ | |
| Viagra Generic | 150mg | 360 + 10 Pills | 423.48€ 403.31€ | |
| Viagra Generic | 100mg | 270 + 10 Pills | 270.47€ 257.59€ | |
| Viagra Generic | 50mg | 180 + 8 Pills | 158.82€ 151.26€ | |
| Viagra Generic | 100mg | 360 + 10 Pills | 330.21€ 314.49€ | |
| Viagra Generic | 100mg | 60 + 4 Pills | 96.36€ 91.77€ | |
| Kamagra Soft Tabs | 100mg | 32 Pills | 120.11€ 114.39€ | |
| Kamagra Oral Jelly | 100mg | 220 + 18 Sachets | 662.24€ 630.70€ | |
| Kamagra | 100mg | 360 + 6 Pills | 839.95€ 799.95€ | |
| Viagra Generic | 150mg | 20 Pills | 55.02€ 52.40€ | |
| Kamagra | 100mg | 32 Pills | 121.24€ 115.47€ |
Sildenafil is contraindicated for use with darunavir; cobicistat when used for pulmonary arterial hypertension (PAH).
Product Description
Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving darunavir. [32] When sildenafil is coadministered with darunavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions. [27][32] Coadministration of darunavir with sildenafil 20 mg tablets PDE5 inhibitors is expected to substantially increase their plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. Sildenafil is contraindicated for use with cobicistat when used for pulmonary arterial hypertension (PAH). If used for erectile dysfunction, the dose of sildenafil should not exceed 25 mg every 48 hours with increased monitoring for adverse reactions during times of coadministration. Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving indinavir.
- Sildenafil tablets 125 mg are available by prescription only.
- They work by inhibiting the PDE5 enzyme.
- Do not mix sildenafil with alcohol to avoid adverse effects.
- Use with caution if you have heart or liver conditions.
- Sildenafil may interact with certain antibiotics.
- Be aware of potential side effects like flushing.
- Take sildenafil about 30-60 minutes before activity.
- Avoid using grapefruit juice while on sildenafil.
Additionally, sildenafil is contraindicated for use with the anti-retroviral protease inhibitors when used for pulmonary arterial hypertension (PAH).28731 When sildenafil is coadminstered with indinavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions. [27] Substantially increased PDE5 inhibitor plasma concentrations are seen and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. In a small pharmacokinetic study, the coadministration of a single dose of sildenafil (25 mg) to patients receiving indinavir (800 mg every 8 hours) resulted in markedly increased sildenafil AUC values (340% increase), as compared to historical controls. The Cmax for indinavir was increased by 48% and the 8-hour AUC was increased 11% following concurrent administration.
- Sildenafil tablets 125 mg can be part of a broader ED treatment plan.
- Psychological counseling may enhance effectiveness.
- Combining therapies can improve outcomes.
- Lifestyle modifications include weight management and exercise.
- Quitting smoking can improve erectile health.
- Vasodilator drugs should be avoided when using sildenafil.
- Maintain a balanced diet alongside medication.
- Support groups can offer additional assistance.
In two of the six subjects, prolonged clinical effects of sildenafil were noted for 72 hours after a single dose of sildenafil.
| Use Case | Description | Typical Dosage | Onset of Action | Duration |
|---|---|---|---|---|
| Erectile Dysfunction | Helps achieve and maintain erections during sex | 125 mg | 30-60 minutes | Up to 4-6 hours |
| Pulmonary Hypertension | Relieves high blood pressure in lung arteries | 125 mg | 15-30 minutes | 4-6 hours |
| Off-Label Uses | Potential uses in other vascular conditions | Varies | Varies | Varies |
Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving lopinavir; ritonavir (Kaletra).
12.1 Mechanism of Action
NOTE: Sildenafil is metabolized principally by the hepatic cytochrome P450 (CYP) 3A4 (major route) and 2C9 (minor route) isoenzymes. [19] Inhibitors of these isoenzymes may reduce sildenafil clearance. Increased systemic exposure to sildenafil may result in an increase in sildenafil-induced adverse effects. The manufacturer recommends dosage reduction in patients receiving potent cytochrome CYP3A4 inhibitors. Consistent with its known effects on the nitric oxide/cGMP pathway, sildenafil was shown to potentiate the hypotensive effects of nitrates.
5.5 Hearing Loss
Deaths have been reported in men who were using sildenafil while taking nitrate or nitrite therapy for angina. Sildenafil administration to patients who are concurrently using organic nitrates or nitrites in any form is contraindicated. The safety and efficacy of tadalafil administered concurrently with any other phosphodiesterase (PDE5) inhibitors, such as sildenafil, has not been studied. The manufacturer of tadalafil recommends to avoid the use of tadalafil with any other PDE5 inhibitors. Coadministration of sildenafil, tadalafil or vardenafil and other organic nitrates has been shown to potentiate the hypotensive effects of nitrates; concomitant administration of these drugs for erectile dysfunction with nitrates is contraindicated.
2.2 Recommended Dosage in Pediatric Patients
[20][22][23] Many methscopolamine-containing products list methscopolamine nitrate as the ingredient. Therefore, the concomitant use of sildenafil, tadalafil or vardenafil and products which contain methscopolamine nitrate is not recommended. Sildenafil is metabolized principally by cytochrome P450 (CYP) 3A4 (major route) and 2C9 (minor route) isoenzymes. Cimetidine is a known inhibitor of hepatic CYP enzymes and reduces the metabolism of sildenafil. Cimetidine (800 mg) caused a 56% increase in plasma sildenafil concentrations when coadministered with sildenafil 50 mg to healthy volunteers. Coadministration of lopinavir; ritonavir (Kaletra) with these drugs is expected to substantially increase their plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. Lopinavir; ritonavir is contraindicated for use with sildenafil when sildenafil is used for the treatment of pulmonary arterial hypertension (PAH). [37] If coadministered when sildenafil is used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions.
- Sildenafil is sometimes used off-label for other health issues.
- Its interaction with blood thinners should be monitored.
- Men with retinitis pigmentosa should avoid sildenafil.
- Always inform healthcare providers about all treatments.
- Use sildenafil in conjunction with a healthy lifestyle.
- Avoid unnecessary medication to prevent side effects.
- Be aware of potential drug interactions with sildenafil.
- Proper storage maintains medication efficacy over time.
Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving nelfinavir. [38] When sildenafil is coadministered with nelfinavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions.
- Common side effects include headaches and facial flushing.
- Less common effects may include nasal congestion or upset stomach.
- Do not use sildenafil if allergic to it or similar drugs.
- Pregnant women should consult a healthcare provider before use.
- Be aware of the signs of allergic reactions.
- Sildenafil may also be indicated for certain heart conditions.
- Emergency services should be contacted if adverse reactions occur.
- Keep a record of any side effects experienced.
[27][38] Coadministration of nelfinavir with PDE5 inhibitors is expected to substantially increase their plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving tipranavir.
503A vs 503B
Population data from patients in clinical trials also indicate a reduction in sildenafil clearance when it was coadministered with cimetidine. If possible, cimetidine use should be avoided in patients who take sildenafil. Etravirine is an inducer of CYP3A4; coadministration may result in decreased sildenafil concentrations. Dosage adjustments may lovegra sildenafil be needed based on clinical efficacy. Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving ritonavir.
Are you currently using Sildenafil (Viagra, Revatio)?
Coadministration of ritonavir with sildenafil results in an 11-fold increase of sildenafil AUC; one death has been reported in a patient who received sildenafil in combination with ritonavir and Fortovase. [25] Substantially increased sildenafil plasma concentrations may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. If coadministered when sildenafil is used for erectile dysfunction, a reduced dose of sildenafil 25 mg every 48 hours with increased monitoring for adverse reactions is recommended. [26][27] When sildenafil is used for the treatment of pulmonary arterial hypertension (PAH), the use of ritonavir is contraindicated because a safe and effective dose has not been established. Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving saquinavir.
Comparing Sildenafil vs. Tadalafil Dosage
Sildenafil is contraindicated for use with the anti-retroviral protease inhibitors when used for pulmonary arterial hypertension (PAH). [28] If sildenafil is coadministered with saquinavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions. [27][28] Coadministration of saquinavir, especially when ‘boosted’ with ritonavir, with PDE5 inhibitors is expected to substantially increase their plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection. One death has been reported in a patient who received sildenafil in combination with ritonavir and saquinavir (Fortovase). Particular caution should be used when prescribing phosphodiesterase type 5 (PDE5) inhibitors to patients receiving amprenavir. [28] When sildenafil is coadministered with tipranavir and used for erectile dysfunction, use sildenafil at reduced doses of 25 mg every 48 hours with increased monitoring for adverse reactions.
| Tip | Explanation | Goal |
|---|---|---|
| Follow dosage instructions | Take exactly as prescribed | Prevent side effects or interactions |
| Be aware of side effects | Recognize common side effects and when to seek help | Ensure safety |
| Avoid alcohol and heavy meals | May decrease effectiveness or increase side effects | Maximize efficacy |
| Report health issues | Communicate with doctor about any adverse reactions or concerns | Maintain safety and treatment efficacy |
[27][28] Coadministration is expected to substantially increase the PDE5 inhibitor plasma concentrations and may result in increased associated adverse events including hypotension, syncope, visual changes, and prolonged erection.