Products
Vardenafil is commercially available in the form of film-coated tablets and oral tablets (Levitra, co-marketing drug: Vivanza). It has been approved in many countries since 2003. Generic versions were approved in 2018.
Structure and properties
Vardenafil (C23H32N6O4S, Mr = 488.6 g/mol) is present in the drugs as vardenafil hydrochloride trihydrate, a piperazine derivative and a colorless crystalline powder. Vardenafil is structurally closely related to the first phosphodiesterase-5 inhibitor sildenafil (Viagra).
Effects
Vardenafil (ATC G04BE09) has vasodilatory and antihypertensive properties. It causes relaxation of smooth muscle in the corpus cavernosum and an increase in blood flow to the penis during sexual stimulation. The effects are due to potent inhibition of cGMP-specific phosphodiesterase type 5 (PDE-5), resulting in an increase in cGMP, which mediates these effects as a second messenger of nitric oxide (NO). Vardenafil has a medium-long half-life of 4-5 hours. It is thus in approximately the same range as sildenafil.
Indication
For the treatment of erectile dysfunction in men.
Dosage
According to the professional information. The tablets are taken a maximum of once a day 25 to 60 minutes before sexual intercourse and independently of meals. However, a high-fat meal may delay the onset of action.
Contraindications
- Hypersensitivity
- Certain cardiovascular diseases
- Severe hepatic insufficiency
- Terminal renal failure
- Degenerative retinal diseases
- Vardenafil should not be combined with nitrates, NO donors, or amyl nitrite.
- Concomitant administration with potent CYP3A4 inhibitors is also not indicated.
Full precautions can be found in the drug label.
Interactions
Vardenafil is metabolized primarily by CYP3A4 and to a lesser extent by CYP3A5 and CYP2C9. Corresponding drug-drug interactions are possible. Nitrates, NO donors, amyl nitrite, and antihypertensives may cause a dangerous drop in blood pressure.
Adverse effects
The most common possible adverse effects include flushing (transient redness of the skin), headache, dyspepsia, nausea, dizziness, and nasal congestion.
