Sildenafil Dosage

Medically reviewed by Drugs.com. Last updated on Dec 1, 2023.

Usual Adult Dose for Erectile Dysfunction

TABLETS (Viagra)
Initial dose: 50 mg orally once a day, as needed, about 1 hour prior to sexual activity
Maintenance dose: May increase to 100 mg or decrease to 25 mg once a day, based on efficacy and tolerability.
Maximum dose: 100 mg orally once a day

Comments:

• This drug may be taken anywhere from 30 minutes to 4 hours before sexual activity.

Use: For the treatment of ED

Usual Adult Dose for Pulmonary Hypertension

TABLETS (Revatio)/ORAL SUSPENSION (Revatio, Liqrev):
Initial dose: 20 mg orally 3 times a day
Maintenance dose: May titrate up to 80 mg orally 3 times a day, if required, based on symptoms and tolerability.
Maximum dose: 80 mg orally 3 times a day

IV: 10 mg IV bolus 3 times a day

Comments:

• No adjustment for body weight is required for IV dosing.
• The 10 mg IV bolus dose is predicted to provide an equivalent pharmacological effect to that of 20 mg orally.
• Doses up to a maximum of 80 mg orally 3 times a day are supported by delayed clinical worsening with long-term use in clinical studies despite a lack of observed dose-response improvement in exercise ability in short-term clinical studies.
• In adults 65 years or older, use caution with dose selection due to a higher incidence of compromised renal, cardiac, and/or hepatic function, and of concomitant disease or drug therapy.

Use: For the treatment of PAH (WHO Group I) to improve exercise ability and delay clinical worsening

Usual Geriatric Dose for Erectile Dysfunction

TABLETS (Viagra)
Initial dose: 25 mg orally once a day, as needed, about 1 hour prior to sexual activity
Maintenance dose: May titrate up to 100 mg orally once a day, based on effectiveness and toleration.
Maximum dose: 100 mg orally once a day

Comments:

• This drug may be administered anywhere from 30 minutes to 4 hours before sexual activity.
• A reduced starting dose is recommended in older adults due to higher systemic exposure as compared to younger adults.

Use: For the treatment of ED

Usual Pediatric Dose for Pulmonary Hypertension

TABLETS (Revatio)/ORAL SUSPENSION (Revatio)
1 to less than 18 years:

• Weight 20 kg or less: 10 mg orally 3 times a day
• Weight greater than 20 kg to 45 kg: 20 mg orally 3 times a day
• Weight greater than 45 kg: 20 mg orally 3 times a day; dose may be titrated up to a maximum of 40 mg orally 3 times a day, if required, based on symptoms and tolerability

Maximum dose: Unknown

Use: For the treatment of pulmonary arterial hypertension (WHO Group I) to improve exercise ability and, in pediatric patients too young to perform standard exercise testing, pulmonary hemodynamics thought to underlie improvements in exercise

Renal Dose Adjustments

ERECTILE DYSFUNCTION:
Mild to Moderate Renal Dysfunction (CrCl 30 to 80 mL/min): No adjustment recommended
Severe Renal Dysfunction (CrCl less than 30 mL/min):

• Consider a starting dose of 25 mg orally once a day, about 1 hour prior to sexual activity

PULMONARY ARTERIAL HYPERTENSION:
Mild, Moderate, or Severe Renal Dysfunction (CrCl 80 to less than 30 mL/min): No adjustment recommended

Liver Dose Adjustments

ERECTILE DYSFUNCTION:
Mild, Moderate, or Severe Liver Dysfunction (Child-Pugh A, B, or C):

• Consider a starting dose of 25 mg orally once a day, about 1 hour prior to sexual activity.

PULMONARY ARTERIAL HYPERTENSION:
Mild or Moderate Liver Dysfunction (Child-Pugh A or B): No adjustment recommended
Severe Liver Dysfunction (Child-Pugh C): Data not available in this population.

Dose Adjustments

ERECTILE DYSFUNCTION:
Administration with Alpha-Blockers:

• Initiate treatment with 25 mg orally once a day, as needed, about 1 hour prior to sexual activity
• Patients should be stable on alpha blocker therapy prior initiating treatment with this drug.

Administration with CYP450 3A4 Inhibitors (e.g., ketoconazole, itraconazole, saquinavir) or Erythromycin:

• Consider a starting dose of 25 orally once a day, as needed, about 1 hour prior to sexual activity.

Administration with Ritonavir:

• Recommended dose: 25 mg orally, as needed, about 1 hour prior to sexual activity
• Maximum dose: 25 mg orally within a 48 hour period

Precautions

CONTRAINDICATIONS:
Erectile Dysfunction (ED):

• Known hypersensitivity to either the active component or to any of the ingredients; hypersensitivity reactions have been reported, including rash and urticaria
• In patients who are using a guanylate cyclase (GC) stimulators, such as riociguat; phosphodiesterase type 5 inhibitors (PDE5), including this drug, may potentiate the hypotensive effects of GC stimulators.
• In patients who are using nitric oxide donors such as organic nitrates or organic nitrites in any form either regularly and/or intermittently; this drug has been shown to potentiate the hypotensive effects of nitrates based on its mechanism of action
• After patients have taken this drug for ED, it is unknown when nitrates, if necessary, can be safely administered.
• Although plasma levels of this drug at 24 hours post-dose are much lower than at peak concentration, it is unknown whether nitrates can be safely co-administered at this time point.

Pulmonary Arterial Hypertension (PAH):

• Concomitant use of organic nitrates in any form, either regularly or intermittently, because of the greater risk of hypotension
• Concomitant use of riociguat, a guanylate cyclase stimulator; PDE5 inhibitors, including this drug, may potentiate the hypotensive effects of riociguat.
• Known hypersensitivity to either the active component or to any of the ingredients of the tablet, injection, or oral suspension; hypersensitivity reactions have been reported, including anaphylactic reaction, anaphylactic shock, and anaphylactoid reaction

Safety and efficacy have not been established in patients with ED younger than 18 years.
Safety and efficacy have not been established in patients with PAH younger than 1 year.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Comment:

• Due to high plasma protein binding and poor elimination in urine, removal via hemodialysis is unlikely.

Other Comments

Administration advice:
ERECTILE DYSFUNCTION:

• Tablets: Administer orally with or without food.

PULMONARY ARTERIAL HYPERTENSION:
Tablets: For oral use only.

Oral Suspension (powder):

• Reconstitute product before oral administration, and shake well before use.
• An oral syringe is recommended for dose measurement (and delivery).
• Use within 60 days after reconstitution; discard any remainder after expiration.

Oral Suspension (liquid):

• The liquid suspension is premixed and may contain flavoring.
• Shake well before oral administration and use a calibrated measuring device for accurate dosing.
• Use within 90 days after opening.

IV: Administer as an IV bolus injection; the supplied product is ready for use.

Storage requirements:

• Tablets/IV solution: Store at 20C to 25C (68F to 77F); excursions permitted to 15C to 30C (59F to 86F).
• Oral suspension (liquid): Store at 20C to 25C (68F to 77F); excursions permitted to 15C to 30C (59F to 86F).
• Oral suspension (powder): Store below 30C (86F) in the original package in order to protect from moisture.
• After reconstitution, store below 30C (86F) or in refrigerator at 2C to 8C (36F to 46F); do not freeze.

Reconstitution/preparation techniques:

• Oral suspension (powder): Reconstitute with water (total 90 mL) in separate additions; shake vigorously after each addition. Do not mix with other medications or flavoring; insert adaptor into bottle neck.
• Consult the manufacturer product information for detailed instructions.

Monitoring:

• Cardiovascular: Cardiac status/risk factors (prior to initiation); blood pressure (periodically during treatment in patients with PAH on concomitant anti-hypertensive agents)
• Drug Interactions: For concomitant use of medications that may be contraindicated or for dose adjustment (at baseline and during treatment)
• Ocular: NAION risk factors (prior to initiation)

Patient advice:
All Patients:

• Read the US FDA-approved patient labeling (Patient Information and/or Instructions for Use).
• Tell your healthcare provider about all of the medicines you (or your child take).
• Do not take this drug with:
• Regular and/or intermittent use of nitric oxide donors (e.g., organic nitrates or nitrites) in any form
• Guanylate cyclase stimulators (e.g., riociguat)
• Other PDE5 inhibitors or products containing sildenafil
• Seek immediate medical attention in the event of:
• Sudden loss of vision in one or both eyes
• Sudden decrease or loss of hearing; may be accompanied by tinnitus and dizziness
• An erection that persists longer than 4 hours.

Patients Treated for ED:

• It is not recommended to take this drug more than once a day.
• This medication can cause your blood pressure to unsafely drop suddenly if it is taken with certain other medicines.
• Stop sexual activity and seek medical attention if you experience symptoms such as chest pain, dizziness, or nausea during sex, or if you have any side effect that bothers you or does not go away.
• Use protective measures to guard against sexually transmitted diseases, including the Human Immunodeficiency Virus (HIV).

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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