Vardenafil

Vardenafil

File:Vardenafil.svg
Systematic (IUPAC) name
4-[2-ethoxy-5-(4-ethylpiperazin-1-yl)sulfonyl-phenyl]- 9-methyl-7-propyl- 3,5,6,8-tetrazabicyclo[4.3.0] nona-3,7,9-trien-2-one
Clinical data
Pregnancy category	B3 (Au), B (U.S.)
Routes of administration	Oral
Legal status
Legal status	AU: S4 (Prescription only) UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Bioavailability	15%
Protein binding	95%
Metabolism	Hepatic (CYP3A4)
Biological half-life	4–5 hours
Excretion	Biliary
Identifiers
CAS Number	224785-90-4
ATC code	G04BE09 (WHO)
PubChem	CID 110634
DrugBank	APRD00699
ChemSpider	99300
Chemical data
Formula	C23H32N6O4S
Molar mass	488.604 g/mol[[]]
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Vardenafil (INN) is a PDE5 inhibitor used for treating impotence (erectile dysfunction) that is sold under the trade name Levitra (Bayer AG, GSK, and SP).

History

Vardenafil was co-marketed by Bayer Pharmaceuticals, GSK, and SP under the trade name Levitra. As of 2005, the co-promotion rights of GSK on Levitra have been returned to Bayer in many markets outside the U.S. In Italy, Bayer sells vardenafil as Levitra and GSK sells it as Vivanza, thus, because of European Union trade rules, parallel imports might result in Vivanza sold next to Levitra in the EU.

Clinical use

Main article: PDE5 inhibitor

Vardenafil's indications and contra-indications are the same as with other PDE5 inhibitors; it is closely related in function to sildenafil citrate (Viagra) and tadalafil (Cialis). Structurally, the difference between the vardenafil molecule and sildenafil citrate is a nitrogen atom's position and the change of sildenafil's piperazine ring methyl group to an ethyl group. Tadalafil is structurally different from both sildenafil and vardenafil. Vardenafil's relatively short effective time is comparable to but somewhat longer than sildenafil's.

Adverse drug reactions

The common, adverse drug reactions (side effects) are the same as with other PDE5 inhibitors. The frequent vardenafil-specific side effect is nausea; the infrequent side effects are: abdominal pain, back pain, photosensitivity, abnormal vision, eye pain, facial oedema, hypotension, palpitation, tachycardia, arthralgia, myalgia, rash, itch, and priapism. (Rossi, 2004)

One possibly serious, but rare, side effect with vardenafil is heart attack. Also in rare cases, vardenafil use may damage penile tissue, resulting in permanent impotence. Health Canada (2006)

On 18 October 2007, the U.S. Food and Drug Administration (FDA) announced that a warning about possible deafness (sudden hearing loss) would be added to the drug labels of Vardenafil, and other PDE5 inhibitors.

Drug interactions

Vardenafil, as with all PDE5 inhibitors, should not be used by men taking nitrate medications, because combining them with vardenafil might provoke potentially life-threatening hypotension (low blood pressure).

Dose forms

It is available in 2.5 mg, 5 mg, 10 mg, and 20 mg doses in round orange tablets. The normal starting dose is 10 mg (roughly equivalent to 50 mg of sildenafil). Vardenafil should be taken 1 to 2 hours prior to sexual activity, with a maximum dose frequency of once per day. In some territories, such as the UK, only certain doses may be available, i.e. 5 mg, 10 mg, and 20 mg.

External links

• Official Levitra website
• PubChem Information

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