Sildenafil injection is an intravenous sildenafil formulation within the REVATIO pulmonary arterial hypertension product framework. Current U.S. labeling describes a clear, colorless, sterile, ready-to-use solution containing 10 mg sildenafil in 12.5 mL, equivalent to 0.8 mg/mL.
The formulation bypasses gastrointestinal absorption and oral bioavailability. Current labeling predicts that a 10 mg REVATIO injection dose provides a pharmacological effect from sildenafil plus its N-desmethyl metabolite equivalent to that of a 20 mg oral dose, illustrating why IV and oral milligram amounts should not be treated as directly interchangeable.
This page focuses on the injection as a formulation and regulatory entity. It does not present injectable sildenafil as an erectile-dysfunction route alternative or provide individualized intravenous treatment instructions.
Sildenafil injection is a parenteral dosage form that delivers sildenafil directly into the systemic circulation through an intravenous route. In the current U.S. market, the principal branded product context is REVATIO injection.
Current REVATIO labeling describes the product as a clear, colorless, sterile, ready-to-use solution in a single-dose vial containing 10 mg sildenafil in 12.5 mL, corresponding to a concentration of 0.8 mg/mL.
Because the active drug is supplied as sildenafil citrate, each mL contains 1.124 mg sildenafil citrate equivalent to 0.8 mg sildenafil. The remaining listed formulation components are dextrose and water for injection.
| Feature | REVATIO Injection |
|---|---|
| Dosage form | Sterile ready-to-use injection |
| Route | Intravenous |
| Presentation | Single-dose vial |
| Total sildenafil | 10 mg in 12.5 mL |
| Concentration | 0.8 mg/mL |
| Drug substance | Sildenafil citrate |
REVATIO injection belongs to the pulmonary arterial hypertension product framework rather than the erectile-dysfunction product framework associated with Viagra-type sildenafil products.
Current REVATIO labeling includes tablets, powder for oral suspension and injection under the broader WHO Group I PAH indication. The injection section of the dosage information provides an intravenous regimen for adults.
The injectable formulation therefore represents one branch of the REVATIO product family, not a universal injectable form of every sildenafil indication.
| Product Element | Current Context |
|---|---|
| Brand | REVATIO |
| Active moiety | Sildenafil |
| Drug substance | Sildenafil citrate |
| Indication framework | Pulmonary arterial hypertension |
| Injection population in dosage section | Adults |
| Route | Intravenous |
The most important pharmacokinetic difference between oral and intravenous sildenafil is systemic input. Oral tablets and suspension must pass through gastrointestinal absorption and presystemic processes before sildenafil reaches systemic circulation.
Intravenous sildenafil bypasses gastrointestinal absorption and first-pass input limitations by delivering the formulation directly into the systemic circulation. This removes oral bioavailability as an input variable.
That difference explains why oral and IV sildenafil should not be compared milligram-for-milligram without reference to product-specific pharmacokinetic data.
| Feature | Oral Sildenafil | REVATIO Injection |
|---|---|---|
| Route | Oral | Intravenous |
| GI absorption | Required | Bypassed |
| Oral bioavailability | Relevant | Not applicable to IV input |
| First-pass processes | Can contribute | Bypassed during systemic input |
| Current PAH forms | Tablet or suspension | Sterile injectable solution |
The existence of an FDA-approved sildenafil injection does not mean that erectile-dysfunction sildenafil can simply be administered intravenously instead of orally.
REVATIO injection was developed and approved within the PAH treatment framework. The original FDA review specifically evaluated the IV formulation for adults with PAH who were temporarily unable to take oral REVATIO and for whom continuity of treatment was considered appropriate.
Current ED sildenafil products use their own approved dosage forms and labeling. Route, indication and product identity therefore need to remain separate even though the active moiety is sildenafil.
| Question | Answer |
|---|---|
| Same active moiety as ED sildenafil? | Yes |
| Approved as an ED injection? | No |
| Part of REVATIO PAH framework? | Yes |
| Automatically interchangeable with an oral ED product? | No |
REVATIO injection received a separate New Drug Application because the intravenous formulation and route were not covered automatically by the earlier oral REVATIO approval.
FDA approved NDA 22-473 for REVATIO injection on November 18, 2009. The regulatory record describes it as a new dosage form containing sildenafil at 0.8 mg/mL for the PAH treatment context.
The approval illustrates a central regulatory principle: prior approval of sildenafil as an active drug does not automatically approve every future dosage form or route. The broader chronology remains on the sildenafil FDA approval page.
| Regulatory Element | REVATIO Injection |
|---|---|
| Application | NDA 22-473 |
| Approval date | November 18, 2009 |
| Regulatory type | New dosage form |
| Strength in approval context | 0.8 mg/mL |
| Clinical framework | Pulmonary arterial hypertension |
REVATIO injection and oral sildenafil products share sildenafil as the active moiety, but their pharmaceutical preparations differ substantially.
The injection contains sildenafil citrate in a sterile aqueous solution with dextrose and water for injection. Oral tablets require solid-dosage excipients, while oral suspensions require a separate liquid or reconstitutable formulation system.
Sharing the same active moiety therefore preserves the core PDE5 pharmacology but does not establish pharmaceutical equivalence among different dosage forms.
| Shared Characteristic | Formulation-Specific Difference |
|---|---|
| Sildenafil active moiety | Intravenous vs oral route |
| PDE5 inhibitor pharmacology | Sterile solution vs tablet or suspension |
| Core molecular target | Different excipient systems |
| Drug identity | Different administration and label context |
Changing the formulation from oral to intravenous does not change sildenafil's molecular target. Sildenafil remains a PDE5 inhibitor and its major active N-desmethyl metabolite retains related PDE5 activity.
What changes is the route by which systemic exposure is established. IV administration removes the absorption and oral-bioavailability steps that precede systemic exposure after tablets or suspension.
Current labeling uses pharmacokinetic and pharmacodynamic bridging to relate the injectable and oral REVATIO regimens: 10 mg IV is predicted to provide a combined parent-plus-metabolite pharmacological effect equivalent to 20 mg oral sildenafil.
| Concept | Relationship |
|---|---|
| Molecular target | PDE5 |
| Active moiety | Sildenafil |
| Major active metabolite | N-desmethyl sildenafil |
| Oral input | Requires absorption |
| IV input | Direct systemic administration |
| Label bridge | 10 mg IV predicted to provide pharmacological effect equivalent to 20 mg oral REVATIO |
REVATIO injection remains subject to sildenafil's systemic safety framework. Current labeling lists concomitant organic nitrates, concomitant riociguat and known hypersensitivity to sildenafil or formulation components as formal contraindications.
Warnings include hypotension from vasodilatory effects, pulmonary edema in pulmonary veno-occlusive disease, sudden visual or hearing changes and other sildenafil-associated precautions. These risks are not removed by using an intravenous route.
The injectable formulation also has product-specific handling characteristics: it is supplied as a sterile single-dose vial and unused solution should be discarded. Broader safety topics remain on the sildenafil warnings page, sildenafil contraindications page and sildenafil drug interactions page.
| Safety / Handling Topic | Injection Context |
|---|---|
| Organic nitrates | Contraindicated |
| Riociguat | Contraindicated |
| Known hypersensitivity | Contraindicated |
| Hypotension | Important vasodilatory warning |
| PVOD | Pulmonary edema risk; use not recommended |
| Vial | Single-dose |
| Unused portion | Discard |
The IV-to-oral relationship is more specific than a simple route comparison. Current REVATIO labeling predicts that a 10 mg injection produces a pharmacological effect of sildenafil plus its active N-desmethyl metabolite equivalent to a 20 mg oral dose.
This two-to-one nominal milligram difference reflects route-dependent systemic input and metabolite contribution rather than greater intrinsic potency of the sildenafil molecule when injected.
It should not be generalized into a conversion rule for other sildenafil products or indications. The broader route comparison is covered on the oral vs injectable sildenafil page.
| Category | Oral REVATIO Reference | REVATIO Injection |
|---|---|---|
| Route | Oral | Intravenous |
| Reference amount in label comparison | 20 mg | 10 mg |
| Absorption | Required | Bypassed |
| Parent + metabolite pharmacological effect | Reference | Predicted equivalent at 10 mg IV vs 20 mg oral |
| Direct mg-for-mg interchangeability | No | No |
Sildenafil injection is one of several approved sildenafil dosage-form contexts. Current U.S. products also include tablets, oral suspension or powder for oral suspension, and oral film.
The injection is distinctive because it is the major intravenous sildenafil dosage form and belongs to the REVATIO PAH framework. Tablets and liquid products can belong to either ED or PAH contexts depending on the specific product, while oral film currently belongs to an ED product context.
The complete dosage-form map is available on the sildenafil formulations page.
| Dosage Form | Route | Example Product Context |
|---|---|---|
| Tablet | Oral | ED or PAH depending on product |
| Oral film | Oral | VYBRIQUE / ED |
| Oral suspension | Oral | REVATIO-type or LIQREV PAH products |
| Injection | Intravenous | REVATIO / PAH |
Injection-related terminology separates the active drug from the dosage form, route and pharmaceutical presentation. These terms are related but not interchangeable.
REVATIO injection is a sterile solution for intravenous use. 'Parenteral' describes administration that bypasses the gastrointestinal tract, while 'IV' identifies the specific intravenous route used by this product.
Strength can be stated as the total amount in the vial or as a concentration: the current product contains 10 mg sildenafil in 12.5 mL, equivalent to 0.8 mg/mL.
| Term | Definition |
|---|---|
| Sildenafil | Active moiety |
| Sildenafil citrate | Drug substance used in the injection |
| Injection | Sterile parenteral dosage form |
| Intravenous / IV | Administration directly into the venous circulation |
| Parenteral | Administration that bypasses the gastrointestinal route |
| 0.8 mg/mL | Sildenafil concentration in current REVATIO injection |
| Single-dose vial | Container intended for one-use handling with unused portion discarded |
REVATIO injection is a sterile intravenous sildenafil formulation used within the pulmonary arterial hypertension product framework. Current labeling supplies 10 mg sildenafil in 12.5 mL, equivalent to 0.8 mg/mL.
Each mL contains 1.124 mg sildenafil citrate equivalent to 0.8 mg sildenafil, 50.5 mg dextrose and water for injection.
Current labeling predicts that 10 mg of REVATIO injection provides a pharmacological effect from sildenafil and its N-desmethyl metabolite equivalent to that of a 20 mg oral dose. This relationship is product-specific and should not be generalized to other sildenafil products.
No. REVATIO injection belongs to the pulmonary arterial hypertension product framework and should not be interpreted as an injectable alternative to ED sildenafil products.
FDA approved REVATIO injection under NDA 22-473 on November 18, 2009 as a new sildenafil dosage form within the pulmonary arterial hypertension context.
The current REVATIO dosage section provides the intravenous regimen for adults. Pediatric dosing in the current label is oral, so the adult IV information should not be generalized into a pediatric injection regimen.