Drug ID: 1d00000140
Drug Name: Avanafil
Generic Names: Stendra
Category: Impotent Agents
Legal Status: Non Opioid Prescription only drug
Indication for Mother: Category C
Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Recommended Dose: The recommended initial dose is 100 mg taken approximately 30 minutes before sexual activity, on an as needed basis.
Recommended In: This medication is a PDE5 inhibitor, prescribed for erectile dysfunction. It relaxes muscles and increases blood flow.
Directions For Use: It comes as a tablet to take by mouth, as directed by your physician.
Storage: Store at 68°F to 77°F (20°C to 25°C).
Dosage Forms: Tablet
Side Effects: Headache, flushing, nasal congestion, nasopharyngitis, and back pain.
In Case of Overdose: In cases of overdose, standard supportive measures should be adopted as required. Renal dialysis is not expected to accelerate clearance because avanafil is highly bound to plasma proteins and is not significantly eliminated in the urine.
Avoid If: Caution should be exercised in patients with history of heart disease, recently undergone heart surgery, stroke, low or high blood pressure, deformed penis shape, vision problem, bleeding problems, kidney or liver disease, any allergy and who are taking other medications.
Patient may develop with increased risk of vision loss, if it is so consult with your doctor immediately.
It should not be co-administered with organic nitrate. Contraindicated in patients with hypersensitivity.
Drug Interaction: Nitrates
Administration of avanafil to patients who are using any form of organic nitrate is contraindicated. In a clinical pharmacology trial, avanafil was shown to potentiate the hypotensive effect of nitrates.
Caution is advised when PDE5 inhibitors are co-administered with alpha-blockers. PDE5 inhibitors, including avanafil, and alpha-adrenergic blocking agents are both vasodilators with blood pressure-lowering effects. When vasodilators are used in combination, an additive effect on blood pressure may be anticipated. In some patients, concomitant use of these two drug classes can lower blood pressure significantly leading to symptomatic hypotension (e.g., dizziness, lightheadedness, fainting).
PDE5 inhibitors, including avanafil, are mild systemic vasodilators. A clinical pharmacology trial was conducted to assess the effect of avanafil on the potentiation of the blood pressure-lowering effects of selected antihypertensive medications (amlodipine and enalapril).
Both alcohol and PDE5 inhibitors, including avanafil, act as vasodilators. When vasodilators are taken in combination, blood pressure-lowering effects of each individual compound may be increased.
Strong CYP3A4 Inhibitors
Ketoconazole, a selective and strong inhibitor of CYP3A4, increased avanafil single-dose systemic exposure (AUC) and maximum concentration (Cmax) equal to 13-fold and 3-fold, respectively, and prolonged the half-life of avanafil to approximately 9 hours. Other potent inhibitors of CYP3A4 (e.g., itraconazole, clarithromycin, nefazadone, ritonavir, saquinavir, nelfinavir, indinavir, atanazavir, and telithromycin) would be expected to have similar effects. Do not use avanafil in patients taking strong CYP3A4 inhibitors.
HIV Protease inhibitor — Ritonavir, a strong CYP3A4 inhibitor, which also inhibits CYP2C9, increased avanafil single-dose Cmax and AUC equal to approximately 2-fold and 13-fold, and prolonged the half-life of avanafil to approximately 9 hours in healthy volunteers. Do not use avanafil in patients taking ritonavir.
Moderate CYP3A4 Inhibitors
Erythromycin (500 mg twice daily) increased avanafil single-dose Cmax and AUC equal to approximately 2-fold and 3-fold, respectively, and prolonged the half-life of avanafil to approximately 8 hours in healthy volunteers.
When administered with avanafil, amlodipine increased the Cmax and AUC of avanafil by approximately 22% and 70%, respectively. The half-life of avanafil was prolonged to approximately 10 hrs.