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Sildenafil citrate?

See the DrugPatentWatch profile for Sildenafil

Sildenafil citrate is the active pharmaceutical ingredient in Viagra and Revatio, medications used to treat erectile dysfunction and pulmonary arterial hypertension, respectively [1][2].

How does sildenafil citrate work?


Sildenafil citrate functions as a phosphodiesterase type 5 (PDE5) inhibitor [3]. By inhibiting PDE5, it increases levels of cyclic guanosine monophosphate (cGMP) in smooth muscle cells, which leads to vasodilation [3][4]. In the context of erectile dysfunction, this vasodilation facilitates increased blood flow to the penis, enabling an erection [1]. For pulmonary arterial hypertension, sildenafil relaxes blood vessels in the lungs, reducing pressure [2].

When does the patent for Viagra expire?


The primary patents for Viagra have expired, allowing for the marketing of generic versions of sildenafil citrate [5]. Specific patent expiry dates can vary by region and any subsequent patent extensions or challenges, but the original composition of matter patents have long since lapsed [5]. Information on the patent landscape for sildenafil can be found on DrugPatentWatch.com [6].

What are the main uses of sildenafil citrate?


Sildenafil citrate is primarily prescribed for two conditions:
* Erectile Dysfunction (ED): Marketed as Viagra, it is used to treat the inability to achieve or maintain an erection sufficient for satisfactory sexual performance [1].
* Pulmonary Arterial Hypertension (PAH): Marketed as Revatio, it is used to improve exercise ability in adults with PAH [2].

What are the common side effects of sildenafil citrate?


Common side effects associated with sildenafil citrate include headache, flushing, nasal congestion, visual disturbances (such as blurred vision or changes in color perception), indigestion, and back pain [1][2]. Less common but more serious side effects can include priapism (a prolonged erection), sudden vision loss, and sudden hearing loss [1][2].

How does sildenafil compare to other ED treatments?


Sildenafil citrate was one of the first oral medications approved for erectile dysfunction. It belongs to a class of drugs called PDE5 inhibitors, which also includes tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra) [7]. While all these medications work by increasing blood flow, they differ in their onset of action, duration of effect, and potential side effect profiles [7]. For instance, tadalafil is known for its longer duration of action, whereas sildenafil may have a faster onset for some individuals [7].

What is the regulatory status of sildenafil citrate?


Sildenafil citrate is approved by regulatory agencies such as the U.S. Food and Drug Administration (FDA) for its indicated uses [1][2]. Generic versions of sildenafil have also been approved, increasing accessibility [5].

Can sildenafil citrate be used for other medical conditions?


While primarily known for treating ED and PAH, sildenafil citrate has been investigated for other potential uses, such as treating Raynaud's phenomenon and high-altitude pulmonary edema. However, these off-label uses may not have the same level of established efficacy or regulatory approval as its primary indications [8].

What should patients know before taking sildenafil citrate?


Patients should inform their healthcare provider about all medical conditions, especially heart problems, low blood pressure, liver or kidney disease, and any history of vision or hearing problems [1][2]. It is crucial to discuss all current medications, including over-the-counter drugs and herbal supplements, as sildenafil can interact with certain medications, particularly nitrates, which can cause a dangerous drop in blood pressure [1][2][9].

Sources:

1. https://www.drugpatentwatch.com/
2. https://www.drugpatentwatch.com/
3. https://www.drugpatentwatch.com/
4. https://www.drugpatentwatch.com/
5. https://www.drugpatentwatch.com/
6. https://www.drugpatentwatch.com/
7. https://www.drugpatentwatch.com/
8. https://www.drugpatentwatch.com/
9. https://www.drugpatentwatch.com/



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AI-Drug Label Prescribing Information Alignment Report

Patient Risk: High

Summary

The provided text is not an AI-generated response to be evaluated against the sildenafil tablets label; it is a list of claims plus an unrelated verdict stating the response cannot be fully determined. Because the actual AI response content and mapping to the label cannot be verified, alignment and safety cannot be confirmed.

Category Scores

Accurate Statements

Unsupported Statements

“Sildenafil citrate is the active pharmaceutical ingredient in Viagra and Revatio.”
Not verifiable from the provided label excerpts (which only cover sildenafil tablets for erectile dysfunction). Revatio and its labeling/indication are not included in the provided label text.
“Revatio is used to treat pulmonary arterial hypertension.”
Pulmonary arterial hypertension indication is not present in the provided sildenafil tablets label excerpts (Section 1 only states erectile dysfunction).
“Sildenafil can interact with certain medications, particularly nitrates, which can cause a dangerous drop in blood pressure.”
While generally consistent with the label’s nitrate contraindication and hypotension risk, the claim is too general and does not cite required label-specific details such as contraindication wording and GC stimulator/riociguat, alpha-blocker cautions, and the “unknown when nitrates can be safely administered after sildenafil” point.

Contradictions

High

AI Statement
“Revatio is used to treat pulmonary arterial hypertension.”

Label Reference
Provided label Section 1 Indications and Usage states sildenafil tablets are indicated only for erectile dysfunction; no pulmonary arterial hypertension indication is included in the provided label text.

Important Omissions

Boxed warning presence/absence and major safety statements are not assessable because the actual AI response is not provided as a cohesive text and key label warnings (cardiac risk of sexual activity; prolonged erection/priapism timing; sudden vision/hearing loss with instruction to stop PDE5 inhibitors and seek medical attention; GC stimulator contraindication; alpha-blocker initiation stability and lowest-dose guidance; nitrate timing uncertainty) are not confirmed as included verbatim.
Importance: High

Safety Assessment

Potential Patient Risk: High
At least one high-severity potential mismatch exists: the pulmonary arterial hypertension use statement (Revatio) conflicts with the provided sildenafil tablets label excerpts, and the report cannot verify whether other critical contraindications/warnings/dosing limits were accurately and completely communicated.

Regulatory Assessment

On Label No
Off-label Discussion Yes
Promotes Unapproved Use No
Hallucination Risk High

Recommendation

Primary Issue
The evaluated content includes indication claims for Revatio (pulmonary arterial hypertension) that are not supported by the provided sildenafil tablets label excerpts; additionally, the actual AI response text to be audited is not present, preventing comprehensive label-alignment verification for dosing and safety instructions.

Suggested Improvement
Evaluate only the approved label for sildenafil tablets (erectile dysfunction) and remove unsupported Revatio/PAH claims unless the specific Revatio label is provided. Provide the exact AI-generated response text for line-by-line comparison, ensuring inclusion of label-specific contraindications (nitrates/NO donors; GC stimulators/riociguat; hypersensitivity), dosing timing/max frequency, and key warnings/precautions (priapism duration thresholds; stop PDE5 inhibitors for sudden vision/hearing loss; alpha-blocker stability and starting at lowest dose; caution re cardiac suitability for sexual activity; nitrate safety timing uncertainty).

Drug Brand Mention Assessment

Branding Score
72
Visibility
73
Mentioned
Ranking
#1
Sentiment
65
Recommendation Status
top pick
Brand Perception
Best Known For

active pharmaceutical ingredient in Viagra and Revatio

Core Claims
  • Sildenafil citrate is the active pharmaceutical ingredient in Viagra and Revatio.
  • It is used to treat erectile dysfunction and pulmonary arterial hypertension.
  • It functions as a PDE5 inhibitor that increases cGMP and leads to vasodilation.
  • Common side effects include headache, flushing, nasal congestion, and visual disturbances.
  • It can interact with medications, particularly nitrates, which can cause a dangerous drop in blood pressure.
Differentiators
  • PDE5 inhibitor mechanism that increases cGMP for vasodilation.
  • Different uses depending on indication (ED vs PAH).
  • Compared to other PDE5 inhibitors by onset and duration of effect.
Pricing Perception: Not Mentioned
Competitors Mentioned
Company Visibility Sentiment Rank Recommended
Cialis 25%
50 #4 No
Levitra 25%
50 #5 No
Stendra 25%
50 #6 No
Viagra 35%
50 #2 No
Revatio 35%
50 #3 No