avanafil(redirected from Stendra)
Pharmacologic class: Phosphodiesterase type 5 (PDE5) inhibitor
Therapeutic class: Erectile dysfunction agent
Pregnancy risk category C
Enhances the effect of nitric oxide by inhibiting PDE5, which is responsible for degradation of cyclic guanosine monophosphate in the corpus cavernosum. Because sexual stimulation is required to initiate the local release of nitric oxide, the inhibition of PDE5 has no effect in the absence of sexual stimulation.
Tablets: 50 mg, 100 mg, 200 mg
Indications and dosages
➣ Erectile dysfunction
Adults: Initially, 100 mg P.O. approximately 30 minutes before sexual activity on an as-needed basis. May increase dosage to 200 mg or decrease to 50 mg based on efficacy or tolerability; use the lowest dosage that provides benefit. Not to exceed one dose daily.
• Concurrent use of moderate CYP3A4 inhibitors
• Concurrent use of alpha blockers
• Hypersensitivity to drug or its components
• Concurrent use of any form of organic nitrates
Use cautiously in:
• severe hepatic or renal impairment (avoid use)
• mild to moderate hepatic or renal impairment
• patients in whom sexual activity is inadvisable due to CV status (particularly those with left ventricular outflow obstruction, such as aortic stenosis or idiopathic hypertrophic subaortic stenosis, and those with severely impaired autonomic blood pressure control)
• patients who have suffered MI, stroke, life-threatening arrhythmia, or coronary revascularization within the last 6 months; patients with resting hypotension (blood pressure less than 90/50 mm Hg) or hypertension (blood pressure greater than 170/100 mm Hg); patients with unstable angina, angina with sexual intercourse, or New York Heart Association Class 2 or greater congestive heart failure; patients with known hereditary degenerative retinal disorders, including retinitis pigmentosa (use not recommended)
• patients with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease); patients who have conditions that may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia); patients with bleeding disorders or active peptic ulceration
• concurrent use of strong CYP3A4 inhibitors, CYP 450 inducers, or other PDE5 inhibitors, or erectile dysfunction therapies (use not recommended)
• concurrent use of moderate CYP3A4 inhibitors
• concurrent use of CYP3A4 inducers (not recommended)
• concurrent use of alpha blockers or other antihypertensives or substantial amounts of alcohol
• elderly patients
• women (not indicated)
• children younger than age 18 (safety and efficacy not established).
☞ Don't give concurrently with nitrates. In a patient who has taken this drug, where nitrate administration is deemed medically necessary in a life-threatening situation, allow at least 12 hours to elapse after the last dose of avanafil before considering nitrate administration. In such circumstances, administer nitrates under close medical supervision with appropriate hemodynamic monitoring.
CNS: headache, dizziness
CV: hypertension, ECG abnormality
EENT: sudden decrease or loss of hearing, tinnitus, nasal congestion, nasopharyngitis, sinusitis, sinus congestion
GI: dyspepsia, nausea, constipation, diarrhea
Musculoskeletal: back pain, arthralgia
Respiratory: upper respiratory tract infection, bronchitis
Skin: flushing, rash, pruritus
Other: influenza, hypersensitivity
Drug-drug. Alpha blockers (such as alfuzosin, tamsulosin), antihypertensives, nitrates (such as isosorbide, nitroglycerin): increased risk of hypotension
Amlodipine: increased avanafil Cmax and area under the curve (AUC)
CYP2C8 substrates (rosiglitazone): increased rosiglitazone AUC and decreased rosiglitazone Cmax
Desipramine, omeprazole: increased AUC and Cmax of these drugs
Moderate CYP3A4 inhibitors (such as amprenavir, aprepitant, diltiazem, erythromycin, fluconazole, fosamprenavir, verapamil), strong CYP3A4 inhibitors (such as atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, ritonavir, saquinavir, telithromycin): increased avanafil plasma concentration
Drug-food. Grapefruit juice: potentially increased avanafil exposure
High-fat diet: reduced drug absorption, decreased peak level
Drug-behaviors. Alcohol use (substantial amounts): increased risk of hypotension
• Monitor CV status carefully.
• Monitor patient's hearing.
• Tell patient to take tablets with or without food but not to take with grapefruit juice.
• Tell patient that high-fat diet may interfere with drug efficacy.
• Advise patient to take drug 30 minutes before sexual activity.
• Tell patient not to exceed prescribed dosage or take more than one dose daily.
☞ Instruct patient to stop sexual activity and contact prescriber immediately if chest pain, dizziness, or nausea occurs.
☞ Teach patient to recognize and immediately report serious cardiac and vision problems, and sudden decrease in or loss of hearing.
☞ Caution patient never to take drug with nitrates, because of risk of significant hypotension.
• Advise patient to avoid or limit alcohol use, because substantial use may cause increase in heart rate, decrease in standing blood pressure, dizziness, and headache.
• Inform patient that this drug can cause serious interactions with many common drugs. Instruct him to tell all prescribers he's taking avanafil.
• Instruct patient not to take other erectile dysfunction drugs while taking this drug.
• Instruct patient to report priapism (persistent, painful erection) or erections lasting more than 4 hours.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, foods, and behaviors mentioned above.
ClassificationTherapeutic: erectile dysfunction agents
Pharmacologic: phosphodiesterase type 5 inhibitors
Time/action profile (effect on BP)
|PO||within 1 hr||1–2 hr||unknown|
Adverse Reactions/Side Effects
Central nervous system
- headache (most frequent)
Ear, Eye, Nose, Throat
- nasal congestion
- sudden hearing/vision loss
- flushing (most frequent)
- back pain
Drug-Drug interactionBlood levels and effects may be ↑ by CYP3A4 inhibitors, concurrent use of strong CYP3A4 inhibitors including atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, saquinavir, and telithromycin is contraindicated.A similar but lesser effect is expected with moderate CYP3A4 inhibitors including erythromycin, aprepitant, diltiaziem. fluconazole, fosamprenavir, ritonavir and verapamil ; initial dose should not exceed 50 mg/24 hr.↑ risk of hypotension with nitrates, alpha-adrenergic blockers, antihypertensives and alcohol (more than 3 units); concurrent use with nitrates is contraindicated, dosage adjustments may be necessary with others.If nitrates are medically necessary, at 12 hr should pass following avanafil adminitration.
- Determine ED before administration. Avanafil has no effect in the absence of sexual stimulation.
Potential Nursing DiagnosesSexual dysfunction (Indications)
Ineffective tissue perfusion (Adverse Reactions)
- Oral: Administer dose as needed for ED at least 30 min prior to sexual activity
- May be administered without regard to food.
- Instruct patient to take avanafil as needed for ED at least 30 min before sexual activity and not more than once per day. Inform patient that sexual stimulation is required for an erection to occur after taking avanafil.
- Advise patient that avanafil is not indicated for use in women.
- Caution patient not to take avanafil concurrently with alpha adrenergic blockers (unless on a stable dose) or nitrates. If chest pain occurs after taking avanafil, instruct patient to seek immediate medical attention.
- Advise patient to avoid excess alcohol intake (≥3 units) in combination with avanafil; may increase risk of orthostatic hypotension, increased heart rate, decreased standing BP, dizziness, headache.
- Instruct patient to notify health care professional promptly if erection lasts longer than 4 hr, if they are not satisfied with their sexual performance, develop unwanted side effects or if they experience sudden or decreased vision loss in one or both eyes or loss or decrease in hearing, ringing in the ears, or dizziness.
- Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications that may interact with avanafil.
- Inform patient that avanafil offers no protection against sexually transmitted diseases. Counsel patient that protection against sexually transmitted diseases and HIV infection should be considered.
- Male erection sufficient to allow intercourse.