Primary Treatment for Erectile Dysfunction

Stendra is indicated for the therapeutic management of Erectile Dysfunction (ED), or sexual impotence, in adult men. The medication is used across conditions where the penis fails to adequately harden and expand when a man is sexually excited, or the inability to sustain sufficient firmness for sexual activity. The core indications include types of manifestations where erectile function is compromised. This domain helps address symptom clusters that create noticeable physiological strain, primarily the functional failure of erection.

Supportive Relief for Circulatory Failure

The medication is commonly used across conditions presenting with acute or recurrent episodes of insufficient local responsiveness. This includes use in patients with ED symptoms linked to underlying conditions where functional stability becomes affected, such as diabetes mellitus or hypertension. Stendra is commonly used to help with symptoms that interfere with daily comfort, and provides support that helps ease the overall symptom burden.

Facilitating Situational Functional Response

Stendra may be part of symptomatic management in scenarios requiring assistance with the situational functional response of the penis, such as supporting functional stability following specific procedures like nerve-sparing prostatectomy. Applied in clinical settings that involve episodic or fluctuating manifestations, the key benefit is that it assists with maintaining functional stability when sexual stimulation is present.

Quick Fact: Relief for Functional Failure Stendra is relevant for easing symptoms that interfere with daily comfort and is used across the full spectrum of ED severity: mild, moderate, and severe.

Regulatory References

1. NIH MedlinePlus overview of Avanafil

Who Can and Cannot Use Stendra?

Stendra (Avanafil) is officially approved only for use in adult men aged 18 and older for the treatment of Erectile Dysfunction (ED). Its safety and effectiveness have not been established in women and it is not indicated for use in the pediatric population.

Absolute Contraindications

Regulatory documents strictly prohibit the use of Stendra in patients with specific conditions or who are taking certain medications, due to the risk of severe adverse events:

• Patients using any form of organic nitrate or Guanylate Cyclase stimulators (e.g., riociguat).
• Patients taking strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir).
• Patients with specific recent cardiovascular events (e.g., stroke or myocardial infarction within the last six months).
• Patients with severe cardiovascular instability, including uncontrolled hypertension or severe hepatic or severe renal impairment.

Conditional Use and Restrictions

Use requires caution or specific dose limitations for patients with mild-to-moderate hepatic or renal impairment. Conditional use is also specified for patients taking alpha-blocker therapy or moderate CYP3A4 inhibitors.

Interactions with other medicines and products

Stendra's interaction profile is strictly defined by regulatory documents, focusing on combinations that present significant pharmacokinetic or pharmacodynamic risks. The official classification identifies agents that must be avoided entirely and those requiring specific administration constraints.

Prohibited Combinations (Contraindications)

The co-administration of Avanafil with any form of organic nitrate is formally contraindicated due to the severe risk of potentiating hypotensive effects. Absolute prohibition also applies to co-administration with Guanylate Cyclase (GC) stimulators, such as riociguat. Furthermore, the use of Avanafil is contraindicated with Strong CYP3A4 Inhibitors, including ketoconazole, ritonavir, and clarithromycin, because these agents significantly impede the drug's metabolic clearance, resulting in a dangerous increase in systemic exposure.

Interaction-Related Restrictions

Combining Avanafil with Moderate CYP3A4 Inhibitors (e.g., erythromycin, diltiazem) is subject to specific regulatory dose constraints. This restriction is based on the elevated drug exposure caused by partial inhibition of the primary clearance pathway. Additionally, co-administration with alpha-blockers or other antihypertensive medicines may lead to additive peripheral vasodilation and symptomatic hypotension. Consumption of substantial amounts of alcohol is associated with a risk of hypotension, and clearance-based restrictions apply, with use not recommended in patients with severe hepatic or severe renal impairment.

How Stendra Works: Mechanism of Action

Stendra (Avanafil) functions by selectively blocking the enzyme Phosphodiesterase type 5 ( PDE5). This enzyme’s role is the hydrolysis (breakdown) of the crucial signaling molecule, cyclic guanosine monophosphate ( cGMP), which initiates smooth muscle relaxation in the penis. By inhibiting PDE5, the drug effectively stabilizes the concentration of cGMP within the smooth muscle cells of the corpus cavernosum.

The drug's action sustains the Nitric oxide ( NO)- cGMP signaling cascade, which is initiated by the release of NO from penile nerve and endothelial cells. Stendra prolongs the half-life of the subsequent cGMP signal by preventing its breakdown. This sustained signal drives the dephosphorylation of myosin light chains, contributing to the relaxation of the vascular smooth muscle and vasodilation.

The drug's influence on the NO- cGMP pathway modifies the vascular resistance in the arteries supplying the erectile tissue. This localized vasodilation increases the arterial inflow of blood, resulting in the engorgement of the corpus cavernosum. This change in local hemodynamics is the physiological consequence that results in penile tumescence and rigidity.

How Stendra is Used: Official Administration Guidelines

The use of Stendra (Avanafil) is governed by specific instructions defining the precise conditions under which the oral tablets are administered. The medicine is supplied as an immediate-release oral tablet in strengths of 50 mg, 100 mg, and 200 mg. It is intended for intermittent, as-needed use, rather than a scheduled daily regimen, and must never be taken more than once every 24 hours.

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Dosing and Timing

The recommended starting dose is 100 mg. The maximum dose permitted within a 24-hour period is 200 mg, and the minimum dose is 50 mg. The dose used may be increased or decreased based on individual response, without exceeding the maximum stated limit.

Administration requires specific timing relative to anticipated sexual activity. The 100 mg and 200 mg doses should be taken approximately 15 minutes before activity. For the 50 mg dose, this window extends to approximately 30 minutes before activity. The tablet may be taken with or without food. A key procedural condition is that sexual stimulation is required for the medicine to function effectively.

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Population-Specific Constraints

Specific use constraints exist for certain patient populations. For patients already stable on alpha-blocker therapy, the recommended initial dose is 50 mg. Similarly, for individuals taking moderate CYP3A4 inhibitors, the maximum dose is restricted to 50 mg per 24 hours. Use is not recommended for patients with severe renal or hepatic impairment.

Research Evidence / Overview of Studies for Stendra

Core research for Avanafil (Stendra) included Phase III Randomized Controlled Trials (RCTs), where studies explored the active substance compared to a placebo (an inactive control) over short-term periods, typically about 12 weeks. These short-term RCTs were used to explore and measure how symptoms evolved in the observed patient populations.

These studies explored a patient's daily functioning or activity level by measuring changes in standardized, patient-reported outcomes. Key metrics used in the research included the percentage of attempts that led to successful vaginal penetration (SEP2), the percentage of attempts that led to successful completion of intercourse (SEP3), and measured changes in the IIEF-EF Domain Score. Research highlights measurements taken during the study period; studies reported how the measured rates of successful penetration and intercourse completion evolved in the observed populations. Findings describe group patterns, not personal outcomes, and research does not determine whether an individual will respond similarly.

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Evidence in Specific Clinical Situations

Research in Men with Diabetes Mellitus

Dedicated short-term placebo-controlled trials were evaluated in men whose Erectile Dysfunction was associated with Diabetes Mellitus, primarily Type 2. These studies examined outcomes related to episodic or acute changes. Studies monitored patterns of measured functional outcomes in this population.

Research Following Nerve-Sparing Prostatectomy

Additional Phase III RCTs were specifically conducted to explore short-term symptom patterns in men who had developed ED following a nerve-sparing radical prostatectomy. Studies reported patterns related to measured changes in the IIEF-EF Domain Score during the short-term, 12-week follow-up period. The duration of controlled follow-up was 12 weeks.

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Duration of Studies and Long-Term Follow-up

The central body of evidence comes from short-term RCTs with follow-up durations typically of 12 weeks. While these studies examined short-term changes, limited information is available regarding outcomes over longer periods. Open-label extension studies, lasting up to 52 weeks, described measurements over intermediate periods. However, because these studies lack a concurrent placebo comparator, the level of evidence is different from the core RCTs. Evidence for long-term outcomes is not fully established beyond the one-year mark.

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Research Gaps and Areas of Uncertainty

Research provides context about group patterns but does not offer individual predictions; the evidence highlights what is known and what is still uncertain. Limited information is available for men over 70, and data for certain groups remain insufficient (e.g., men with severe renal or hepatic impairment). Comparative evidence is lacking from large-scale studies directly comparing measured functional outcomes of Avanafil against other approved PDE5 inhibitors. Post-market commitments continue to explore specific physiological outcomes, such as effects on spermatogenesis and multiple vision parameters.

Key Studies & References

1. Long-Term Safety and Efficacy Study of Avanafil in Men With Erectile Dysfunction (NCT00853606)

Common questions about Stendra (FAQ)

Q: Is Stendra the brand name for a newer type of medication for erectile dysfunction?

A: Stendra is the brand name for the active compound avanafil. Official product information classifies it as a second-generation PDE5 inhibitor, which indicates it is a newer compound within this class of medications used to treat erectile dysfunction.

Q: Is Stendra known to be a faster-acting treatment compared to older PDE5 inhibitors?

A: Regulatory documents and clinical studies describe Stendra as having a rapid onset of action, with peak concentration reached quickly. This pharmacokinetic profile contributes to its positioning as a fast-acting option compared to older PDE5 inhibitors.

Q: Is there a risk of very low blood pressure when using Stendra?

A: Yes, due to its function as a vasodilator, official warnings address the risk of hypotension (very low blood pressure) when using Stendra. This risk is specifically highlighted when Stendra is combined with certain other medications or when substantial amounts of alcohol are consumed.

Q: Are there specific antibiotics or antifungal medicines that interact with Stendra?

A: Official labeling places restrictions on Stendra's use alongside strong and moderate CYP3A4 inhibitors. This enzyme-inhibiting category includes certain types of antibiotics (such as clarithromycin) and antifungal medicines (such as ketoconazole) as they may elevate the levels of Stendra in the body.

Q: Are there any age-related guidelines regarding the use of Stendra, such as for men over 65?

A: Official studies have not found specific age-related problems that would restrict the general use of Stendra in elderly men. However, regulatory documents state there is limited specific clinical data available for men who are over the age of 70.

Q: Why is Stendra considered a 'second-generation' PDE5 inhibitor?

A: Stendra is classified as a second-generation PDE5 inhibitor mainly because of its high selectivity for the PDE5 enzyme. This high selectivity, which is detailed in pharmacological studies, distinguishes it from older drugs in the same class.

Q: What is the general success rate described in the clinical trials for Stendra?

A: Clinical trials measured the success of Stendra using standardized metrics, such as the ability to achieve successful penetration (SEP2) and successful completion of intercourse (SEP3). Research findings describe how the measured rates for these functional outcomes were consistently higher when compared to the placebo group.

Q: Does Stendra help with sexual desire or only help with maintaining an erection?

A: Stendra is a medication for erectile function and is not intended to treat sexual desire. According to official information, Stendra works by augmenting the blood flow required to facilitate an erection following sexual stimulation and does not affect libido.

Q: Is Stendra available as a lower-cost generic drug?

A: Yes, the active ingredient in Stendra is avanafil, and the FDA has approved lower-cost generic versions of the drug. These generics are approved in all three available tablet strengths: 50 mg, 100 mg, and 200 mg.

Q: How long can the effects of Stendra be expected to last?

A: The drug’s maximal duration of action is typically reported in regulatory documents as up to six hours. Pharmacokinetic data also indicate that the drug has a plasma half-life of between three and five hours.

Q: Do high-fat meals affect the time it takes for Stendra to start working?

A: Yes, the co-administration of Stendra with a high-fat meal may affect how quickly the medication starts to work. Official documents state that a high-fat meal can delay the time it takes for the drug to reach its maximum concentration in the body, which can delay the onset of action.

Q: What are the official restrictions regarding using Stendra with other PDE5 inhibitor drugs?

A: Stendra belongs to the class of medications known as PDE5 inhibitors. Official patient safety information includes warnings that the drug is not to be used simultaneously with other medications in the same PDE5 inhibitor class.

Q: What are the known interactions between Stendra and grapefruit or grapefruit juice?

A: Official drug interaction information states that the consumption of grapefruit or grapefruit juice is generally advised to be limited or avoided while using Stendra. This is because grapefruit can raise the drug's levels in the body and potentially increase the risk of side effects.

Q: What are the key research findings on Stendra's side effect profile versus other similar drugs?

A: Pharmacological data submitted to regulatory agencies highlight Stendra's high selectivity for the PDE5 enzyme over other related enzymes. This factor is used to suggest potential differences in the occurrence of certain class-related side effects when compared to older PDE5 inhibitors.

Q: Does Stendra protect against sexually transmitted infections (STIs) or diseases?

A: No, Stendra is not a barrier method and does not protect against the transmission of sexually transmitted infections (STIs). Official patient safety information explicitly states that the medication does not offer protection against STIs, including HIV.

Storage Conditions

Stendra (avanafil) tablets must be stored at Controlled Room Temperature, defined as 20^circC to 25^circC (68^circF to 77^circF). Storage environments must be controlled to prevent exposure to excess heat or cold; therefore, the medication must be kept from freezing.

Environmental protection is required: the tablets must be stored away from moisture and direct light. The product should remain in the original container, which should be kept tightly closed.

Child Safety and Disposal

Consistent with official labeling, Stendra must be stored out of the sight and reach of children in a secure location.

Regarding disposal, patients are instructed not to keep outdated medicine. Unused or expired tablets should be disposed of by consulting a pharmacist or healthcare professional for guidance on following local pharmaceutical waste regulations.