Vardenafil : Structure and chemical information.
Vardenafil : Structure and chemical information.

What is Vardenafil

  • Vardenafil is a drug that is used for the treatment of erectile dysfunction (inability to attain penile erection during sexual activity).

Vardenafil brand name

  • The drug is available under generic name Vardenafil and brand names Levitra, Staxyn ODT, and Vivanza.
  • Initially three pharmaceutical companies were responsible for the co-marketing of Vardenafil namely, Shering Plouh (now owned by Merck and Co), Bayer, and GlaxoSmithKline (GSK).
  • Bare Health Care Pharmaceuticals is responsible for its manufacture and is distributed by

What is the source of the drug (natural or synthetic)

  • Vardenafil is a synthetic (man-made) pharmaceutical anti-impotence medication.

What does Vardenafil do

Why is this medication prescribed?

  • Vardenafil plays a key role in the treatment of complications related to the sexual activitye., erectile dysfunction or impotence.
  • However, this drug does not provide any protection against sexually transmitted diseases like syphilis, HIV, hepatitis B etc.
  • Vardenafil acts by enhancing blood flow to the male penis and helps in attaining and keeping erection.

Pharmacophore structure: Information about the chemical structure of the drug

Vardenafil chemically belongs to the class of organic compounds which are known as benzenesulphonamides characterized by a sulphonamide group that is S-linked to the benzene ring.

The detailed chemical classification of Vardenafil is described below:

  Kingdom Organic compounds 
Super Class Benzenoids
Class Benzene and substituted derivatives
Sub Class Benzenesulphonamides
Direct Parent Benzenesulphonamides

Chemical information of the drug

  • Vardenafil is available as monohydrochloride salt which selectively brings about the inhibition of cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type (PDE5).
  • It is a synthetic pharmaceutical compound with a molecular formula C23H32N6O4S.
  • The molecular weight of the compound is 488.603 Da.
  • Chemically, Vardenafil is known as 2-{2-ethoxy-5-[(4-ethylpiperazin-1-yl)sulfonyl]phenyl}-5-methyl-7-propyl-1H,4H-imidazo[4,3-f][1,2,4]triazin-4-one.
  • Vardenafil is nearly colorless, solid in texture and has a water solubility of 0.11 mg/mL.
  • Vardenafil is slightly soluble in acetone, soluble in ethanol and freely soluble in methanol.
  • The melting point of Vardenafil is 192 °C.

Vardenafil strengths

  • Vardenafil is available in tablet form for oral administration: regular tablets and orally disintegrating tablets.
  • It is available in different dosage strength of 2.5, 5, 10 and 20 mg/tablet.
  • The tablet is orange in colour, film coated and round with “2.5”, “5”, “10”, and “20” on one side corresponding to the different doses of the drug respectively and “BAYER” cross debossed on other side.
  • Each tablet contains active Vardenafil HCl and inactive ingredients such as yellow ferric oxide, colloidal silicon dioxide, titanium dioxide, polyethylene glycol, microcrystalline cellulose, red ferric oxide, magnesium stearate, hypromellose, and crospovidone.

Vardenafil uses

How the medicine works (mode of action)?

  • The mode of action of Vardenafil is same as that of other drugs used for the treatment of erectile dysfunction such as viagra and cialis.
  • Penile erection occurs by rushing of the blood in the penis via enlargement of the blood vessels responsible for delivering blood to the penis and decrease in the size of blood vessels taking blood away from the penis.
  • During sexual stimulation, nitric oxide is released in the penis responsible for activating the enzyme, guanylate cyclase that produces cyclic guanosine monophosphate (cGMP).
  • The cGMP plays an important role in the amount of blood flow in the penis during stimulation due to its action in increasing or decreasing the size of blood vessels bringing or carrying away blood in the penis.
  • Vardenafil maintains the levels of cGMP by inactivating the cGMP specific enzyme known as phosphodiesterase-5 (PDE-5) and thus enhances the penile erection.
Vardenafil: Mode of action.
Vardenafil: Mode of action.

What are the recommended doses of Vardenafil

  • The recommended dose of the drug for adult with erectile dysfunction is usually 10 mg once a day which has to be taken 60 minutes before the sexual intercourse.
  • However, the dose may be increased to a maximum of 20 mg or decreased to 5 mg depending upon the efficiency or the side effects of the drug.
  • The drug can be taken orally either in presence or absence of food.
  • In case of orally disintegrating tablet (ODT), only one tablet is recommended per day 60 minutes prior to the sexual activity.
  • ODT should not be swallowed with water but kept on tongue until it disintegrates.
  • In case of specific population and in cases where the individual is continuously on this medication, the dosing recommendations are as follows:
  • Geriatric dose (patients 65 years or older): An initial dose of 5 mg
  • Children dose: not recommended in children upto 16 years
  • Dose in patients of stable alpha blocker therapy: An initial dose of 5 mg. In case of concomitant use with some CYP3A4 inhibitors, the recommended doses may vary from 2.5 to 5 mg as directed:
  • ritonavir- a single maximum dose of 2.5 mg in 72 hours
  • itraconazole: 400 mg daily; ketoconazole, saquinavir, indinavir, atazanavir: 400 mg daily; and clarithromycin –a single maximum dose of 2.5 mg in 24 hours
  • intraconazole: 200 mg daily; ketoconazole: 200 mg daily; and erythromycin –a single maximum dose of 5 mg in 24 hours
  • Dose in hepatic impairment: mild cases- no dose adjustment required; moderate cases- an initial dose of 5 mg and maximum of 10 mg; severe cases-not evaluated
  • Dose in renal impairment – in mild, moderate and severe cases there is no need to adjust the doses. No evaluation done in case of renal dialysis

When should I discontinue, withhold or modify the dose of Vardenafil

  • The usual dosing of the drug (i.e. 10 mg per day) may vary depending upon the efficiency and side effects of the drug in a particular individual.
  • Dosage adjustment is required in case of geriatric population.
  • No dosage adjustment is necessary in renal impairment (mild, moderate or severe) patients and patients with mild hepatic impairment.
  • The drug is contraindicated in case of pregnancy, breastfeeding or hypersensitive response to any component of the drug.
  • Vardenafil use should be withheld in case of sudden vision loss.
  • Co-administration of Vardenafil with nitrates and nitric oxide donors is contraindicated.
  • The dosage of the drug has to be adjusted in case you are taking inhibitors of CYP4503A4.

What are the pharmacokinetic properties of the drug

  • Pharmacokinetic studies suggested that after oral administration, Vardenafil is rapidly absorbed and has a bio-availability of approximately 15%.
  • It has been observed that following a 20 mg dose of maximum (or peak) plasma concentration is achieved in 30 to 120 minutes in the fasted state.
  • Following absorption the majority (95%) of the drug is bound to plasma proteins.
  • The drug is mainly metabolized by the hepatic enzyme CYP3A4along with two other isoforms, namely, CYP3A5 and CYP2C.
  • The average median half-life of Vardenafil is 4-5 hours.
  • Vardenafil is mainly excreted in the feces (approximately 91-95%) in the form of metabolites and very little amount in the urine (2-6%).
  • The average steady state volume of distribution of the drug is 208 litres.

Which pregnancy category (A; B; C; D; X) has been assigned to Vardenafil

  • The Vardenafil is classified by US FDA pregnancy category: B
  • Due to lack of adequate and well-controlled studies the use of Vardenafil in pregnant women is contraindicated and recommended only when benefit justifies the risk.
  • Laboratory animal studies have shown increased frequency of the fetus damage.
  • Studies support the excretion of the drug into animal milk. However, no adequate data is available on excretion of Vardenafil into human breast milk.
  • Despite these facts caution should be exercised when taking Vardenafil.

How to take Vardenafil

  • Vardenafil is available in tablet form for oral administration by mouth with or without food.
  • Follow the instructions carefully as directed on prescription leaflet and take Vardenafil exactly as directed.
  • It is also recommended to take drug about 1 hour before sexual intercourse.
  • It is advisable not to take more than one tablet daily.
  • The time duration between the drug uses should be at least 24 hours.
  • Do not change the dose of the drug as prescribed by your doctor. Since, the dosage is based on patient medical condition, treatment responses and usage with other drugs.

How to store the drug

  • Vardenafil is stored at 25°C (77°F) and excursion permitted to 15-30°C (59-86°F).
  • Store the medicine away from light and moisture.
  • Medicine should not be stored in the bathroom.
  • The drug should be kept away from children and pets.

How to dispose the medicine

  • Throw away unused and opened, outdated or no longer used container.
  • Also dispose the old medicine after the expiration date.

Does Vardenafil has approval from government / FDA /or any other related agencies

  • Vardenafil has received its official approval from US Food and Drug Administration (FDA) in August 2003 for the treatment of erectile dysfunction.

Other uses of the drug

  • Vardenafil may also be used for the treatment ofpremature ejaculation.

What special dietary precautions should I follow

  • Grapes and its juice are known to interact with Vardenafil and increased its adverse effects via increasing the levels of the drug in the blood.
  • Consult your doctor regarding the use of grapefruit products with your doctor or pharmacist.
  • Alcohol consumption can also enhance some side effects of the drug.

What precautions should I follow while using Vardenafil

  • Do not use the medicine if you are hypersensitive or allergic to any of the ingredients.
  • Before taking Vardenafil, tell your doctor about your medical history preferentially if you have any kind of liver disease, heart disease, kidney disease, eye disorders, bleeding disorders, or blood pressure problems.
  • Alcoholic beverages, grapefruit, or grapefruit juice should be avoided.
  • It is usually recommended to avoid driving, use of machinery or any chore requiring alertness or clear vision.
  • Consult with your doctor and pharmacist if you are taking any prescription and non-prescription medications or herbal products.
  • Consult your doctor in case of any query.
  • Avoid use of other drugs used for the treatment of impotence.

Vardenafil side effects

In addition to the associated benefits, Vardenafil also is accompanied with the side effects some of which are more common, others less common whereas some that fade away with time while you take the drug. It is always recommended to consult a doctor if you encounter any of the side effects.

Some of the less commonly occurring side effects but requiring medical attention is outlined as:

  • Blurred or decreased vision or blindness
  • Hives and itching
  • Chills
  • Pain or discomfort in the neck, jaw, back, or arms
  • Difficulty with swallowing or breathing
  • Sweating
  • Eye pain
  • Fainting
  • Slow or fast heartbeat
  • Chest tightness, pain, heaviness, or discomfort
  • Dizziness
  • Unusual tiredness
  • Confusion
  • Nausea and vomiting
  • Swelling of the face, eyelids, lips, around the eyes, or tongue
  • Skin rashes

In some cases the incidence are rarely known such as hearing loss. There are some adverse effects that disappear while consuming the drug with time. But, if any of them keep on persisting, consult your doctor.

More common side effects include:

  • stuffy nose
  • redness of the neck, face, upper chest, and arms
  • sneezing

Less commonly occurring side effects include:

  • Diarrhea
  • Pain in stomach, back or eye
  • Congestion
  • Ejaculation problem
  • Fast heartbeat
  • Dry or sore mouth or throat
  • Face swelling
  • Muscle stiffness or pain in joints
  • Itching skin
  • Acid or sour stomach or chest
  • Loss of appetite
  • Sleeplessness and drowsiness
  • Shivering, cough or fever
  • Feeling of discomfort
  • Stomach discomfort
  • Swollen joints
  • Changes in vision or dim vision

Besides these, Vardenafil may also be associated with some long term effects. These include:

  • Hypersensitivity effects: allergic reactions.
  • Nervous system effects: sleep disorder, headache, amnesia, dizziness, seizure.
  • Genitourinary effects: hematospermia, penile hemorrhage, increased erection.
  • Ocular effects: eye discomfort, photophobia, visual color distortions or disturbances including vision loss, eye pain, increase in intraocular pressure, conjunctivitis.
  • Cardiovascular effects: myocardial infarction, ischemic attack, hypertension, tachycardia, sudden cardiac death, cerebrovascular hemorrhage, palpitation.
  • Respiratory effects: sinusitis, rhinitis, sinus or nasal congestion
    Dermatologic effects: photosensitivity reaction, erythema, angioedema, rashes, allergic edema.
  • Renal effects: increase in the levels of creatinine kinase.
    Hepatic effects: Increase in transaminases, and gamma-glutamyl-transferase.
  • Gastrointestinal effects: nausea, diarrhea, dyspepsia, abdominal and gastrointestinal pain, dry mouth.
  • Musculoskeletal effects: back pain, increased muscle cramping and tone.

Vardenafil overdose

  • If you overdose the drug contact with your doctor or pharmacist for symptomatic and supportive measures.
  • The symptoms of overdose include back or muscle pain, abnormal vision.

Vardenafil missed dose

  • It is not applicable in this case.

Does Vardenafil have any interaction with other drugs

Vardenafil may interact with one of the following drugs. Care should be taken when you are taking these medications together.

  • Drugs for the treatment of chest pain (e.g. nitrates such as isosorbide, nitroglucerin)
  • Recreational drugs called “poppers” consisting of amyl or butyl nitrite
  • Drugs to treat high blood pressure or a prostate disorder (alpha blocker medication) including terazosin (Hytrin), prazosin (Minipress), doxazosin (Cardura), alfuzosin (Uroxatral),  tamsulosin  (Flomax)
  • Drugs for treating erectile dysfunction-ED or pulmonary hypertension (such as tadalafil, sildenafil)
  • Drugs for treatment of tuberculosis i.e., isoniazid
  • Antidepressant medications like nefazodone
  • Antibiotic such as erythromycin (Erythrocin, Pediazole), telithromycin (Ketek), dalfopristin/quinupristin (Synercid), or clarithromycin (Biaxin)
  • Antifungal medication such as ketoconazole (Nizoral), itraconazole (Sporanox), or voriconazole (Vfend); miconazole (Oravig),
  • Drugs for high blood pressure or a prostate disorder, including prazosin (Minipress), terazosin (Hytrin), doxazosin (Cardura), alfuzosin (Uroxatral), tamsulosin (Flomax)
  • Heart or blood pressure medication such as verapamil (Covera, Calan, Verelan, Isoptin), nicardipine (Cardene), or diltiazem (Dilacor, Tiazac, Cardizem)
  • Drugs that alter hyeart rhythm such as quinidine (Quin-G), amiodarone (Pacerone, Cordarone), procainamide (Pronestyl, Procan), or sotalol (Betapace)
  • Drugs for HIV/AIDS including such as saquinavir (Invirase), delavirdine (Rescriptor), indinavir (Crixivan), atazanavir (Reyataz), fosamprenavir (Lexiva), or ritonavir (Kaletra, Norvir)

This list of drugs interacting with Vardenafil is not complete and other drugs may also interact with it. Always consult your doctor about the medications you use.

Does Vardenafil have any interaction with diseases

It has been suggested that Vardenafil should be administered in certain diseases very cautiously due to its interaction with the diseased state. These are as follows:

  • Vardenafil should not be used in cases when the sexual activity is not recommended due to underlying cardiovascular status.
  • The drug should be used very cautiously by patients having deformed penis or by patients suffering from conditions that predispose them to multiple myeloma, sickle cell anemia, or leukemia.
  • Vardenafil use is prohibited in patients with known retinal disorders, including retinitis pigmentosa.
  • The use of Vardenafil is not recommended in patients with severe hepatic insufficiency.
  • Avoid use of Vardenafil in patients on renal dialysis.
  • Patients with underlying NAION (non-arteritic anterior ischemic optic neuropathy, a rare condition that causes decreased vision, and even permanent loss of vision) risk factors could be adversely affected by use of Vardenafil.
  • Vardenafil provides no protection against sexually transmitted diseases and hence proper counselling of patients required.
  • Combination therapy of Vardenafil with other erectile dysfunction therapies is usually contraindicated.
  • Concomitant use of Vardenafil with alpha-blockers can drastically lower the blood pressure (hypotension) and hence should be avoided.
Vardenafil disease interaction.
Vardenafil disease interaction.

Where can I get more information

Your pharmacist or health care provider can provide more information about Ezetimibe.

Clinical research and current scenario of the drug

  • Placebo-controlled studies have suggested a dose effect in the occurence of some adverse reactions (dyspepsia, headache, nausea, flushing, and rhinitis) over the 5 mg, 10 mg, and 20 mg doses of Vardenafil.
  • Double-blind, placebo-controlled studies of patients with diabetes mellitus have demonstrated significant improvement in erectile function in aprospective-dose (10 and 20 mg Vardenafil).
  • In some patients the use of the drug is not recommended due to lack of controlled clinical data on the safety or efficacy:
  • Renal disease requiring dialysis
  • Retinal disorders, including retinitis pigmentosa
  • Severe cardiac failure
  • Unstable angina; hypertension; hypotension; recent history of stroke, or arrhythmia
  • Severe hepatic impairment
  • Myocardial infarction
References from chemical, biological and toxicological databases

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About Dr. Manish Goyal 38 Articles
Manish Goyal, obtained his Bachelor of Science degree in Biology from Rajasthan University in 2002. In 2005 he was granted a Master of Science in Biology from the same institution. In 2007, he has joined the Department of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology where he has completed his doctoral studies. The focus of his research is on infectious disease, using excellent cutting edge tools of protein biochemistry, molecular biology and cell biology. Manish is the recipient of multiple awards including, D. P. Burma Best Poster Awards in 81st Annual meeting of Society of Biological Chemist, Receipt of the Ranbaxy Science Foundation Young research scholar award 2012 in the field of biomedical science, and INSPIRE young faculty award by Department of Science and Technology, Govt. of India.