7 DRUG INTERACTIONS

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

6.2 Postmarketing Experience

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. sildenafil increases effects of nitroglycerin rectal by additive vasodilation. Either increases effects of the other by additive vasodilation.

What Is the Maximum Safe Sildenafil Dosage?

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 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. 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.

Coadministration of these phosphodiesterase inhibitors with clarithromycin, a CYP3A4 inhibitor is not recommended.

Highlights of Prescribing Information

These events may be accompanied by tinnitus and dizziness.Trademarks are the property of their respective owners.Manufactured for:Chartwell RX, LLCCongers, NY 10920L71823Revised 03/2024Pharmacist Print Patient Information at: Advise the patient to read the FDA-approved patient labeling (Patient Information and Instructions for Use). Inform patients of contraindication of sildenafil with regular and/or intermittent use of organic nitrates. Inform patients that sildenafil is also marketed as VIAGRA ®for erectile dysfunction. Advise patients taking sildenafil not to take VIAGRA or other PDE-5 inhibitors. Advise patients to seek immediate medical attention for a sudden loss of vision in one or both eyes while taking sildenafil.

Warnings for people with certain health conditions

Such an event may be a sign of NAION. Advise patients to seek prompt medical attention in the event of sudden decrease or loss of hearing while taking Sildenafil. These events may be accompanied by tinnitus and dizziness. Trademarks are the property of their respective owners. PATIENT PACKAGE INSERT Pharmacist Print Patient Information at: Patient Information has been approved by the U.S. Increased systemic exposure of these drugs may occur with clarithromycin; consider reduction of dosage for phosphodiesterase inhibitors. clarithromycin will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Further information

Food and Drug Administration Revised: February 2024 This Patient Information has been approved by the U.S. Food and Drug Administration Revised: February 2024 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 sildenafil for PAH cobicistatcobicistat will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. 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.

FAQs About Sildenafil Dosage

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 oral sildenafil increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. conivaptanconivaptan will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Delay initiation of treatment with any CYP3A4 substrates for at least 7 days following discontinuation of conivaptan.

• 20mg sildenafil is a low dose used for erectile dysfunction.
• It typically begins working within 30-60 minutes.
• Sildenafil should be taken on an empty stomach for best results.
• Common side effects include headache, flushing, and dizziness.
• Consult a doctor before using 20mg sildenafil to ensure safety.

conivaptan will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

• Sildenafil may be less effective in men with certain health conditions like diabetes.
• Be aware of potential vision changes, such as blue-tinted vision.
• Discontinue use and consult a doctor if adverse reactions occur.
• Sildenafil can cause priapism, a painful prolonged erection needing urgent care.
• Safe sexual activity depends on your overall cardiovascular health.

crizotinibcrizotinib increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. If concomitant use of strong CYP3A inhibitors is unavoidable, reduce crizotnib to 250 mg PO qDay.

4. Contraindications

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 sildenafil tables for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

Indications and Usage for Sildenafil Tablets

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. 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. After discontinuation of a strong CYP3A inhibitor, resume crizotinib dose used prior to initiating the strong CYP3A4 inhibitor.

• Sildenafil works by relaxing blood vessels to increase blood flow.
• 20mg dosage is suitable for men with mild to moderate ED.
• It is available by prescription or over-the-counter in some regions.
• Avoid alcohol while taking sildenafil to prevent side effects.
• Do not exceed the prescribed dose to reduce health risks.

crizotinib increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

• Patient support resources are available for those taking sildenafil.
• Many pharmaceutical manufacturers offer patient assistance programs.
• Non-profit organizations provide information and support for ED and PAH.
• The Pulmonary Hypertension Association offers resources for PAH patients.
• Urology care foundations provide educational materials on ED treatments.
• Online forums and support groups can offer peer support and shared experiences.
• Healthcare providers are the primary source for personalized medical advice.
• Pharmacists are an excellent resource for information on dosing and side effects.
• Mental health professionals can help address psychological aspects of ED.
• Cardiac rehabilitation may be recommended for some PAH patients.
• A multidisciplinary approach often yields the best patient outcomes.

dabrafenibdabrafenib will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Potent CYP3A4 inducers are expected to cause substantial decreases in sildenafil plasma levels dabrafenib will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Potent CYP3A4 inducers are expected to cause substantial decreases in sildenafil plasma levels doxazosinsildenafil increases effects of doxazosin by pharmacodynamic synergism.