Vardenafil
Indications
Vardenafil is used to treat erectile dysfunction (ED).
Pharmacology
Vardenafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released in the corpus cavernosum & activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in an erection. Inhibition of PDE5 enhances erectile function by increasing the amount of cGMP. 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.
Dosage And Administration
The recommended starting dose: 10 mg once daily, taken orally approximately 60 minutes before sexual activity. The dose may be increased to a maximum dose of 20 mg or decreased to 5 mg based on efficacy and side effects. The maximum recommended dosing frequency is once per day. Vardenafil can be taken with or without food.
Geriatrics: A starting dose of 5 mg should be considered in patients >65 years of age.
Renal impaired patients: In patients with renal impairment, no dose adjustment is required.
Hepatic impaired patients: In patients with moderate hepatic impairment, a starting dose of 5 mg is recommended and the maximum dose should not exceed 10 mg. Do not use in patients with severe hepatic impairment.
Interaction
Vardenafil can potentiate the blood pressure lowering effect of antihypertensive agents. In clinical studies, single doses of Vardenafil 20 mg caused a mean decrease in blood pressure of 7 mmHg systolic and 8 mmHg diastolic. Caution should be taken when co-administered with other vasodilators including alpha blockers. Vardenafil does not potentiate the hypotensive effect of alcohol. CYP3A4 inhibitors (ketoconazole, indinavir, ritonavir and erythromycin) may reduce Vardenafil excretion from body.
Contraindications
Administration of Vardenafil with nitrates (either regularly or intermittently) and nitric oxide donors is contraindicated because Vardenafil may potentiate hypotensive effect of nitrates. It is also contraindicated for patients who have shown hypersensitivity to Vardenafil or any of the ingredients of this product.
Side Effects
The most common side effects with Vardenafil are headache, flushing, stuffy or runny nose, indigestion, upset stomach, dizziness or back pain.
Pregnancy And Lactation
Vardenafil is not indicated for women.
Precautions And Warnings
Physicians should consider the cardiovascular status of their patients, since there is a degree of cardiac risk associated with sexual activity. In men for whom sexual activity is not recommended because of their underlying cardiovascular status, Vardenafil generally should not be used.
Overdose Effects
The maximum dose of Vardenafil for which human data are available is a single 120 mg. Where the majority of these subjects experienced blurred vision and back pain. Single doses up to 80 mg and multiple doses up to 40 mg administered once daily over 4 weeks did not show serious adverse effects. In cases of overdose, contact with the doctor immediately.
Therapeutic Class
Drugs for Erectile Dysfunction.
Storage Conditions
Store at room temperature and protect from light and moisture. Keep out of the reach of children.