sildenafil
Enable an agent to identify sildenafil, assess the identity and condition of a recorded material or product, and determine which evidence and constraints govern its handling or intended use.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to identify sildenafil, assess the identity and condition of a recorded material or product, and determine which evidence and constraints govern its handling or intended use.
Sildenafil is a synthetic small-molecule inhibitor of phosphodiesterase type 5 (PDE5) that enhances cyclic guanosine monophosphate-mediated smooth-muscle relaxation and is used to treat erectile dysfunction and pulmonary arterial hypertension.
It can be Resolve a chemical or product record to sildenafil while retaining the supplied salt and formulation distinctions.; Normalize reported sildenafil quantities when the chemical form, reporting basis, and conversion evidence are available.; Compare analytical results with the applicable sildenafil material or product specification.; Retrieve product-specific evidence for pharmacology, indications, interactions, and restrictions.; Flag unresolved identity, quality, storage, or provenance evidence for review or quarantine.; Trace a use or handling constraint to its source, jurisdiction, product, and revision..
Distinguishing features
Chemical identity evidence must resolve to sildenafil; a shared therapeutic use or PDE5-inhibitor classification is insufficient.
A record must distinguish sildenafil as the active moiety from sildenafil citrate as the supplied material form.
A stated mass or strength must identify whether it denotes sildenafil equivalent, salt mass, or total formulated material.
A product name must resolve to a documented composition; branding or packaging alone does not establish sildenafil identity.
Parent sildenafil must be distinguished from its metabolites, impurities, and degradation products.
Scope
+ Sildenafil molecular identity and relationships to salts, particularly sildenafil citrate
+ Material composition, physical form, impurities, and evidence of identity
+ Pharmacological target, activity, and exposure relationships
+ Links to formulations, routes, strengths, and indication-specific products
+ Condition, traceability, handling requirements, and use restrictions
- Independent models of sildenafil citrate or other salts without a registry task requiring that split
- Complete product specifications for individual brands, formulations, or packages
- Patient diagnosis, prescribing decisions, and individualized dosing
- General models of erectile dysfunction or pulmonary arterial hypertension
- Other active substances, including tadalafil and vardenafil
- Manufacturing equipment and organizational quality-management systems
Characteristics
- Chemical identity
- Verified molecular structure and identifiers, with the referenced chemical form stated Prevents confusion between sildenafil, related inhibitors, and chemically distinct material forms.
- Supplied chemical form
- Free base; citrate salt; other documented form; unresolved Determines how composition, analytical identity, and quantity should be interpreted.
- Sildenafil content
- mg per dosage unit, mg/mL, or mass fraction; state active-moiety or salt basis Makes quantities comparable without silently substituting salt mass for active content.
- Assay and impurity profile
- Assay percentage and individual impurity concentrations, with method and reporting basis Supports assessment against the specification applicable to the material or product.
- Solid-state form
- Documented crystalline, amorphous, solvation, or hydration state; unresolved Allows relevant differences in material behavior to be investigated.
- Pharmacological target relationship
- Target, activity type, assay evidence, and experimental conditions Separates an evidenced mechanism from assumptions based on therapeutic classification.
- Formulation and route relationship
- Linked product, dosage form, route, release characteristics, and jurisdiction Prevents properties of one sildenafil product from being applied to every presentation.
- Interaction or contraindication relationship
- Interacting substance or condition, restriction type, applicable label, and evidence date Supports retrieval of applicable restrictions before a use-related action.
- Material disposition
- Unassessed; quarantined; released for specified use; rejected; expired or beyond retest date Distinguishes possession of material from evidence that it is suitable for a particular purpose.
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.sildenafil
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 17 findings · 25 questions.
Sildenafil identity and material boundaries Establishes what counts as sildenafil and how its active-moiety identity relates to supplied materials.
Sildenafil, sildenafil citrate, and sildenafil-containing medicines require connected but distinct records.
Molecular identity
Defines the chemical entity independently of branding or therapeutic use.
Structure-based identification
Record the evidence needed to resolve a candidate substance to sildenafil.
- Which authoritative structure and identifiers define sildenafil, and which instead identify sildenafil citrate? definition
- What analytical evidence distinguishes the recorded material from related PDE5 inhibitors or an incorrectly labeled sample? measurement
Active moiety and supplied form
Separates sildenafil identity from salt composition and formulated presentation.
Salt and quantity basis
Make the chemical form and meaning of every reported quantity explicit.
- Does this record describe sildenafil free base, sildenafil citrate, or a formulated product containing sildenafil? boundary
- Is the reported amount expressed as sildenafil equivalent or salt mass, and what verified composition supports any conversion? measurement
Sildenafil quality and stability Connects material identity, analytical quality, and condition to suitability for a specified purpose.
A sildenafil identity claim alone does not establish pharmaceutical quality or continued suitability after storage.
Analytical quality
Captures sildenafil content and unwanted constituents using applicable methods.
Assay and related substances
Record assay and impurity evidence without assuming one specification covers all material forms.
- Which specification and analytical methods apply to this sildenafil material or finished product? provenance
- What are the measured sildenafil assay and related-substance levels, including reporting basis and quantification limits? measurement
Physical form and storage
Relates documented material form and exposure history to stability evidence.
Condition-dependent suitability
Assess whether the current material remains within supported storage and stability conditions.
- Which physical-form, moisture, dissolution, or degradation measurements are relevant to this sildenafil presentation? measurement
- Following a storage excursion or an exceeded expiry or retest date, what evidence is required before release, retesting, or rejection? action
Sildenafil pharmacology and exposure Organizes evidence connecting sildenafil to biological targets and exposure-dependent effects.
An agent must distinguish substance-level pharmacology from formulation-dependent exposure and individual clinical response.
Target and functional effect
Records target activity and the biological context needed to interpret it.
PDE5 and selectivity evidence
Specify the evidence supporting sildenafil's target relationships and their limits.
- What evidence establishes sildenafil's inhibition of PDE5 and the connection to cGMP signaling? provenance
- Which measurements establish activity at other phosphodiesterases, and under what assay conditions? measurement
Exposure and metabolism
Separates administered amount, systemic exposure, and parent or metabolite activity.
Exposure context
Attach pharmacokinetic observations to their formulation, route, and studied population.
- Which formulation, route, food conditions, and population accompany reported sildenafil exposure measurements? measurement
- Which metabolic pathways and active metabolites are established, and which observations belong to metabolites rather than parent sildenafil? boundary
Sildenafil products and use constraints Links sildenafil to particular medicines and the evidence governing their permitted or restricted use.
Indications, routes, instructions, and restrictions must be resolved at the applicable product and jurisdiction.
Product and indication context
Associates the substance with documented products without collapsing their distinct uses.
Indication-specific product linkage
Record which product and authorization support a stated sildenafil use.
- Which current product authorization supports the stated indication, such as erectile dysfunction or pulmonary arterial hypertension, in the relevant jurisdiction? provenance
- Which route, strength, and administration instructions belong to that product and must not be generalized across sildenafil presentations? boundary
Interaction and action gates
Records evidence that constrains a proposed use or requires qualified review.
Restriction evidence
Represent contraindications, interactions, and warnings with their exact scope and source.
- What do the applicable labels state about nitrates, riociguat, blood-pressure-lowering medicines, and drugs affecting sildenafil metabolism? provenance
- Which documented patient factors, concurrent medicines, or reported adverse events require the proposed action to stop or be referred for clinical review? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This entry covers the chemical active substance, not a particular brand, formulation or individual dose.
- Regulatory status, pharmacopoeial editions and product-specific indications require current verification.
- Pharmacokinetic values vary with patient characteristics and interacting medicines.
- Which of these check these first hold for the sense of sildenafil this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Sildenafil free base
- Sildenafil citrate salt
- Which of these kinds and varieties hold for the sense of sildenafil this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- International Nonproprietary Name (INN) - sildenafil - Names the active substance; sildenafil citrate names its citrate salt.
- CAS Registry Number - 139755-83-2 - Sildenafil free base.
- CAS Registry Number - 171599-83-0 - Sildenafil citrate.
- Molecular formula - C22H30N6O4S - Free-base composition; a formula alone is not a unique structural identifier.
- Which of these identifiers and schemes hold for the sense of sildenafil this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- United States Pharmacopeia-National Formulary (USP-NF), issued by the United States Pharmacopeial Convention, includes a sildenafil citrate monograph.
- The US Food and Drug Administration regulates sildenafil medicines through product-specific approvals and prescribing information.
- The World Anti-Doping Agency prohibits PDE5 inhibitors, including sildenafil, within its category of manipulation of blood and blood components when used to manipulate blood or blood components.
- Which of these standards and regulation hold for the sense of sildenafil this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Treatment of erectile dysfunction.
- Treatment of pulmonary arterial hypertension.
- Research on PDE5 inhibition and nitric oxide-cGMP signalling.
- Which of these real-world use hold for the sense of sildenafil this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Molar mass of sildenafil free base - 474.58 - g/mol
- Molar mass of sildenafil citrate - 666.70 - g/mol
- Terminal elimination half-life - Approximately 3-5 - hours
- Which of these typical measurements hold for the sense of sildenafil this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Concurrent use with organic nitrates or nitric oxide donors can cause dangerous hypotension; concomitant use with riociguat is also contraindicated.
- Common adverse effects include headache, flushing, dyspepsia and nasal congestion.
- Visual disturbances can occur; sudden vision or hearing loss has been reported.
- Prolonged erection and priapism can occur.
- Strong CYP3A inhibitors can increase sildenafil exposure and adverse effects.
- Which of these failure modes and hazards hold for the sense of sildenafil this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Prescription and pharmacist-supplied access differ by jurisdiction and product.
- Approved indications, formulations and age groups differ between national authorisations.
- Which of these regional variation hold for the sense of sildenafil this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Sildenafil citrate - The citrate salt contains sildenafil and a citrate component; sildenafil alone names the active molecular entity.
- Tadalafil - A chemically distinct PDE5 inhibitor with a substantially longer elimination half-life.
- Vardenafil - A chemically distinct PDE5 inhibitor, despite overlapping therapeutic uses.
- Viagra - A brand of sildenafil medicine rather than the chemical substance itself.
- Revatio - A brand of sildenafil medicine associated with pulmonary arterial hypertension rather than a separate active substance.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of sildenafil this model covers, and on what evidence? provenance
What the second pass must settle
- Does an existing Vercy world model already own sildenafil, requiring this registry entry to link to it?
- Which authoritative chemical records and pharmacopoeial specifications should anchor sildenafil identity, salt distinctions, and quality measurements?
- Which jurisdictions and sildenafil products should provide the initial verified indication, route, interaction, and restriction evidence?
- Which solid-state forms and stability attributes materially affect the sildenafil materials represented in the registry?
- How should product-level authenticity and batch-release evidence be linked while keeping this model focused on the registered substance?