12 CLINICAL PHARMACOLOGY

This condition may require prompt medical treatment to prevent serious and permanent damage to your penis.

5.7 Priapism

When used chronically for PAH, sildenafil is contraindicated for use with cobicistat; if used for erectile dysfunction, do not exceed sildenafil 25 mg q48hr cobicistat will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events; contraindication applies to chronic administration of sildenafil for PAH; for ED, not to exceed 25 mg in 48 hr. nelfinavirnelfinavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. nelfinavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Coadministration contraindicated if sildenafil used for pulmonary arterical hypertension.

Sildenafil Tablets for ED

Reduce sildenafil dose if used for erectile dysfunction. nirmatrelvir/ritonavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. nitroglycerin rectalsildenafil increases effects of nitroglycerin rectal by additive vasodilation. Use of nitroglycerin within a few days of PDE5 inhibitors is contraindicated. PDE5 inhibitors have been shown to potentiate the hypotensive effects of organic nitrates. If you experience a sudden loss of vision in one or both eyes, contact your doctor immediately. Check with your doctor right away if you have a sudden decrease in hearing or loss of hearing, which may be accompanied by dizziness and ringing in the ears. If you already use medicine for high blood pressure (hypertension), sildenafil could make your blood pressure go too low. Call your doctor right away if you have blurred vision, confusion, dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly, sweating, or unusual tiredness or weakness. This medicine does not protect you against sexually transmitted diseases (including HIV or AIDS). Use protective measures and ask your doctor if you have any questions about this. Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements. Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. Check with your doctor immediately if any of the following side effects occur: burning feeling in the chest or stomach burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings decrease in amount of urine or the frequency of urination dizziness or lightheadedness, especially when getting up suddenly from a lying or sitting position dryness, redness, scaling, or peeling of the skin increase in the size of the pupil redness, burning, or swelling of the eyes redness, itching, or tearing of the eyes seeing shades of colors differently than before swelling of the face, hands, feet, or lower legs unusual feeling of burning or stinging of the skin Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them: pain or tenderness around the eyes and cheekbones diarrhea or stomach cramps (severe or continuing) numbness or tingling of the hands, legs, or feet redness, soreness, swelling, or bleeding of the gums sensation of motion, usually whirling, either of one's self or of one's surroundings sexual problems in men (continuing), including failure to experience a sexual orgasm sores in the mouth and on the lips Other side effects not listed may also occur in some patients.

If you notice any other effects, check with your healthcare professional. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088. 50 mg PO ~1 hr before sexual activity; however, may be taken anywhere from 30 min to 4 hr before sexual activity Maximum dosing frequency is once per day Based on effectiveness and toleration, may increase dose to maximum of 100 mg or decrease to 25 mg Indicated for treatment of pulmonary arterial hypertension (PAH) (World Health Organization [WHO] Group I) to improve exercise ability and delay clinical worsening Revatio (PO), Liqrev: 20 mg PO TID; may titrate up to 80 mg TID, if required, based on symptoms and tolerability Revatio (IV): 10 mg IV bolus TID 10-mg IV predicted to provide pharmacologic effect equivalent to 10-mg oral dose Do not exceed recommended PO/IV dose Viagra, VibriqueSevere (eg, cirrhosis): Consider initial dose of 25 mg Severe (eg, cirrhosis): Consider initial dose of 25 mg RevatioMild or moderate (Child-Pugh A or B): No dose adjustment requiredSevere (Child-Pugh C): Not studied Mild or moderate (Child-Pugh A or B): No dose adjustment required Viagra, VibriqueMild or moderate (CrCl 30-80 mL/min): No dose adjustment requiredSevere (CrCl <30 mL/min): Consider initial dose of 25 mg Mild or moderate (CrCl 30-80 mL/min): No dose adjustment required Severe (CrCl <30 mL/min): Consider initial dose of 25 mg RevatioAny severity, including severe (CrCl <30 mL/min): No dose adjustment required Any severity, including severe (CrCl <30 mL/min): No dose adjustment required Indicated in children aged 1-17 years for treatment of pulmonary arterial hypertension (PAH) (WHO Group I) to improve exercise ability and, in pediatric patients too young to perform standard exercise testing, pulmonary hemodynamics thought to underly improvements in exercise 20-45 kg: 20 mg PO TID Maximum dose in pediatric patients not identified Based on experience in adults, dose may be titrated up to 40 mg TID, if required, based on symptoms and tolerability Mild or moderate (Child-Pugh A or B): No dose adjustment required Any severity, including severe (CrCl <30 mL/min): No dose adjustment required ≥65 years: 25 mg PO initially ~1 hr before sexual activity; however, may be taken anywhere from 30 min to 4 hr before sexual activity Maximum dosing frequency is once per day Based on effectiveness and toleration, may increase dose to maximum of 100 mg or decrease to 25 mg Indicated for treatment of pulmonary arterial hypertension (PAH) (World Health Organization [WHO] Group I) to improve exercise ability and delay clinical worsening PO: 20 mg PO TID; may titrate up to 80 mg TID, if required , based on symptoms and tolerability 10-mg IV predicted to provide pharmacologic effect equivalent to 10-mg oral dose Recommended PO/IV dose not to be exceeded Adding Revatio to bosentan does not have any beneficial effect on exercise capacity Clinical trials found no significant difference in response between elderly patients and younger adults; however, cautious dose selection should be considered in elderly because of greater frequency of decreased hepatic, renal, and cardiac function, as well as comorbid conditions and concomitant pharmacotherapy Compared with healthy younger volunteers, healthy elderly volunteers (≥65 years) had reduced clearance of sildenafil, resulting in approximately 84% and 107% higher plasma concentrations of sildenafil and its active N-desmethyl metabolite, respectively atazanaviratazanavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

In case of emergency/overdose

Although not all of these side effects may occur, if they do occur they may need medical attention. Check with your doctor immediately if any of the following side effects occur: burning feeling in the chest or stomach burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings decrease in amount of urine or the frequency of urination dizziness or lightheadedness, especially when getting up suddenly from a lying or sitting position dryness, redness, scaling, or peeling of the skin increase in the size of the pupil redness, burning, or swelling of the eyes redness, itching, or tearing of the eyes seeing shades of colors differently than before swelling of the face, hands, feet, or lower legs unusual feeling of burning or stinging of the skin Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them: pain or tenderness around the eyes and cheekbones diarrhea or stomach cramps (severe or continuing) numbness or tingling of the hands, legs, or feet redness, soreness, swelling, or bleeding of the gums sensation of motion, usually whirling, either of one's self or of one's surroundings sexual problems in men (continuing), including failure to experience a sexual orgasm sores in the mouth and on the lips Other side effects not listed may also occur in some patients.

How does sildenafil work (mechanism of action)?

If you notice any other effects, check with your healthcare professional. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088. 50 mg PO ~1 hr before sexual activity; however, may be taken anywhere from 30 min to 4 hr before sexual activity Maximum dosing frequency is once per day Based on effectiveness and toleration, may increase dose to maximum of 100 mg or decrease to 25 mg Indicated for treatment of pulmonary arterial hypertension (PAH) (World Health Organization [WHO] Group I) to improve exercise ability and delay clinical worsening Revatio (PO), Liqrev: 20 mg PO TID; may titrate up to 80 mg TID, if required, based on symptoms and tolerability Revatio (IV): 10 mg IV bolus TID 10-mg IV predicted to provide pharmacologic effect equivalent to 10-mg oral dose Do not exceed recommended PO/IV dose Viagra, VibriqueSevere (eg, cirrhosis): Consider initial dose of 25 mg Severe (eg, cirrhosis): Consider initial dose of 25 mg RevatioMild or moderate (Child-Pugh A or B): No dose adjustment requiredSevere (Child-Pugh C): Not studied Mild or moderate (Child-Pugh A or B): No dose adjustment required Viagra, VibriqueMild or moderate (CrCl 30-80 mL/min): No dose adjustment requiredSevere (CrCl <30 mL/min): Consider initial dose of 25 mg Mild or moderate (CrCl 30-80 mL/min): No dose adjustment required Severe (CrCl <30 mL/min): Consider initial dose of 25 mg RevatioAny severity, including severe (CrCl <30 mL/min): No dose adjustment required Any severity, including severe (CrCl <30 mL/min): No dose adjustment required Indicated in children aged 1-17 years for treatment of pulmonary arterial hypertension (PAH) (WHO Group I) to improve exercise ability and, in pediatric patients too young to perform standard exercise testing, pulmonary hemodynamics thought to underly improvements in exercise 20-45 kg: 20 mg PO TID Maximum dose in pediatric patients not identified Based on experience in adults, dose may be titrated up to 40 mg TID, if required, based on symptoms and tolerability Mild or moderate (Child-Pugh A or B): No dose adjustment required Any severity, including severe (CrCl <30 mL/min): No dose adjustment required ≥65 years: 25 mg PO initially ~1 hr before sexual activity; however, may be taken anywhere from 30 min to 4 hr before sexual activity Maximum dosing frequency is once per day Based on effectiveness and toleration, may increase dose to maximum of 100 mg or decrease to 25 mg Indicated for treatment of pulmonary arterial hypertension (PAH) (World Health Organization [WHO] Group I) to improve exercise ability and delay clinical worsening PO: 20 mg PO TID; may titrate up to 80 mg TID, if required , based on symptoms and tolerability 10-mg IV predicted to provide pharmacologic effect equivalent to 10-mg oral dose Recommended PO/IV dose not to be exceeded Adding Revatio to bosentan does not have any beneficial effect on exercise capacity Clinical trials found no significant difference in response between elderly patients and younger adults; however, cautious dose selection should be considered in elderly because of greater frequency of decreased hepatic, renal, and cardiac function, as well as comorbid conditions and concomitant pharmacotherapy Compared with healthy younger volunteers, healthy elderly volunteers (≥65 years) had reduced clearance of sildenafil, resulting in approximately 84% and 107% higher plasma concentrations of sildenafil and its active N-desmethyl metabolite, respectively atazanaviratazanavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Never use combination with chronic 50 mg sildenafil price sildenafil for PAH cobicistatcobicistat will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Never use combination with chronic 50 mg sildenafil price sildenafil for PAH cobicistatcobicistat will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

• Sildenafil has a rapid onset but should not be used as a daily medication without approval.
• It is intended for episodic use before sexual activity.
• Discuss alternative options with a healthcare provider for ongoing issues.

When used chronically for PAH, sildenafil is contraindicated for use with cobicistat; if used for erectile dysfunction, do not exceed sildenafil 25 mg q48hr cobicistat will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events; contraindication applies to chronic administration of sildenafil for PAH; for ED, not to exceed 25 mg in 48 hr. nelfinavirnelfinavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. nelfinavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Coadministration contraindicated if sildenafil used for pulmonary arterical hypertension. Reduce sildenafil dose if used for erectile dysfunction. nirmatrelvir/ritonavir will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. nitroglycerin rectalsildenafil increases effects of nitroglycerin rectal by additive vasodilation.

Use of nitroglycerin within a few days of PDE5 inhibitors is contraindicated. PDE5 inhibitors have been shown to potentiate the hypotensive effects of organic nitrates.

What other drugs will affect sildenafil?

sildenafil increases effects of nitroglycerin rectal by additive vasodilation. Either increases effects of the other by additive vasodilation. Coadministration of PDE-5 inhibitors (eg, avanafil, sildenafil, tadalafil, vardenafil) and guanylate cyclase stimulators (eg, riociguat) is contraindicated due to risk of additive hypotension; do not administer within 24 sildenafil oral strips hr of each other. Either increases effects of the other by pharmacodynamic synergism. Coadministration of vericiguat with PDE-5 inhibitors may result in additive hypotensive effects.

Can I get Sildenafil Citrate without a prescription?

alfuzosinsildenafil increases effects of alfuzosin by pharmacodynamic synergism. sildenafil increases effects of alfuzosin by pharmacodynamic synergism. apalutamideapalutamide will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. sildenafil increases effects of nitroglycerin rectal by additive vasodilation. Either increases effects of the other by additive vasodilation. Coadministration of PDE-5 inhibitors (eg, avanafil, sildenafil, tadalafil, vardenafil) and guanylate cyclase stimulators (eg, riociguat) is contraindicated due to risk of additive hypotension; do not administer within 24 sildenafil oral strips hr of each other. Either increases effects of the other by pharmacodynamic synergism. Coadministration of vericiguat with PDE-5 inhibitors may result in additive hypotensive effects. alfuzosinsildenafil increases effects of alfuzosin by pharmacodynamic synergism. sildenafil increases effects of alfuzosin by pharmacodynamic synergism.

• People with certain health conditions should consult their doctor before use.
• Conditions include heart disease, low blood pressure, or kidney/liver issues.
• Adjustments to dosage may be necessary based on health status.

apalutamideapalutamide will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed. apalutamide will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. asenapinesildenafil increases effects of asenapine by pharmacodynamic synergism.

8.5 Geriatric Use

This condition may require prompt medical treatment to prevent serious and permanent damage to your penis. If you experience a sudden loss of vision in one or both eyes, contact your doctor immediately. Check with your doctor right away if you have a sudden decrease in hearing or loss of hearing, which may be accompanied by dizziness and ringing in the ears. If you already use medicine for high blood pressure (hypertension), sildenafil could make your blood pressure go too low. Call your doctor right away if you have blurred vision, confusion, dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly, sweating, or unusual tiredness or weakness.

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

This medicine does not protect you against sexually transmitted diseases (including HIV or AIDS). Use protective measures and ask your doctor if you have any questions about this. Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements. Along with its needed effects, a medicine may cause some unwanted effects. sildenafil increases effects of asenapine by pharmacodynamic synergism. ceritinibceritinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. ceritinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. chloramphenicolchloramphenicol will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. chloramphenicol will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Dosing & Uses

Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed. apalutamide will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. asenapinesildenafil increases effects of asenapine by pharmacodynamic synergism. sildenafil increases effects of asenapine by pharmacodynamic synergism.

Serious Side Effects

ceritinibceritinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. ceritinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. chloramphenicolchloramphenicol will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. chloramphenicol will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. clarithromycinclarithromycin will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. clarithromycinclarithromycin will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.