Levitra Information

What is the appropriate dose of Levitra?

Currently, Levitra is available in 2.5mg, 5mg, 10mg, and 20mg doses. The standard dose is to take an initial dose of 10mg. This dose is decreased for various medical conditions (liver conditions, end stage renal disease, hypotension, cardiovascular disease, taking other medications, etc.) and increased up to 20mg if the standard dose is not effective in healthy individuals. Men over the age of 65 years will often take a lower dose. Similar to any prescription medication, consult with a physician prior to taking Levitra. The medication is usually taken 25 - 60 minutes prior to sexual activity. If you overdose on Levitra seek immediate medical attention.

Similar to Viagra can individuals buy a larger dose of Levitra and then split the dose?

Yes, individuals can buy the 20mg Levitra tablets and then split the dose into the standard dose of 10mg. Many individuals even split the 20mg tablets into fourths and just take 5mg of Levitra. Individuals should not take more than 20mg of Levitra at any time.

Is Levetra also known as Vardenafil HCL?

Yes, Levitra is the brand name and Vardenafil HCL is the generic name for the medication.

Which company manufactures Levitra?

Levitra is manufactured by the Bayer corporation in Germany and will most likely also be distributed and marketed by GlaxoSmithKline.

Is Levitra an effective treatment option for erectile dysfunction following prostate surgery?

Levitra is extremely effective in treating erectile dysfunction (impotence) following prostate cancer surgery. Some 71% of men who had undergone prostate removal reported significant improvements in erections with Levrita (20mg) versus 12 per cent in men taking placebo (sugar pill). The study concluded that this was an important finding for Levitra, as erectile dysfunction (impotence) following prostate surgery is usually severe.

What is the mechanism of action of Levitra?

Levitra is a new class of medication to help men with erectile dysfunction (impotence) Viagra was the first of the so called  "PDE-5 inhibitors" and Levitra is known in the same class to significantly help individual overcome their erectile dysfunction (impotence). Similar to Viagra, Levitra increases the quantity of blood supplied to the penis improving the erection. Levitra is very selective in inhibiting the  PDE-5 without affecting other isoenzymes. This allows a smaller dose of Levitra to have a more pronounced effect as a larger dose of Viagra (the standard dose of Levitra dose is 10mg while the standard dose of  Viagra dose is 50mg). Through this action, smooth muscle in the penis remains relaxed for a longer period.  This allows for increased blood flow into the cavernous tissue of the penis thereby generating an erection.  Levitra is unique in that it increases a natural occurring process, therefore, only through sexual stimulation will an erection occur.   

More specifically, Penile erection is a haemodynamic process. During sexual stimulation, nitric oxide is subsequently released. The nitric acid activates an enzyme guanylate cyclase, resulting in an increased level of cyclic guanosine monophosphate (cGMP) in the corpus cavernosum of the penis. This  results in smooth muscle relaxation in the penis, allowing increased inflow of blood into the penis. The level of cGMP is regulated by the rate of synthesis via guanylate cyclase and by the rate of degradation via cGMP hydrolysing phosphodiesterases (PDEs).

Levitra is a potent and selective inhibitor of the cGMP specific phosphodiesterase type 5 (PDE5), the most prominent PDE in the human corpus cavernosum. Levitra enhances the effect of endogenous nitric oxide in the corpus cavernosum by inhibiting PDE5. When nitric oxide is released secondary to sexual stimulation, inhibition of PDE5 by Levitra results in increased corpus cavernosum levels of cGMP. Sexual stimulation is required for Levitra to produce its beneficial therapeutic effects. 

Is there a generic version of Levitra?

Levitra is still under the patent of Bayer/GlaxoSmithKline  which have the exclusive rights to market Levitra.  Some companies may advertise a generic version of Levitra, however, this medication is not approved or tested by the FDA or European regulators so you cannot be sure of the purity and/or quality of the medication.

Will I have a spontaneous erection after I take Levitra?

No, men still need some form of sexual stimulation in order to achieve an erection.

Does Levitra help with erectile dysfunction related depression?

Yes, studies have shown that Levitra is effective in treating the depressive symptoms experienced by men with erectile dysfunction (impotence). The studies showed men taking Levitra reported improved erections and fewer depressive symptoms than those men taking a placebo (sugar pill).

How good is Levitra as compared to Viagra in treating erectile dysfunction (impotence)?

Many men in clinical studies have reported that Levitra lasts longer, produces an erection faster, has fewer side effects, and helps more men achieve fuller erections when compared to Viagra. More clinical studies need to be completed to evaluate the two medications. Levitra is the new alternative to Viagra!

Should I eat prior to taking Levitra?

Individuals can take Levitra with or without food, however, preferably not following a heavy or a meal high in fat content. In addition, individuals should not take Levitra with grapefruit juice, alcohol can worsen the erection process.

Why should individuals not drink grapefruit juice while taking Levitra?

Grapefruit juice being a weak inhibitor of CYP3A4 gut wall metabolism, may give rise to modest increases in plasma levels of Levitra.

In addition to the active ingredients, what else is in Levitra?

In addition to the active ingredient, vardenafil HCl, each tablet contains colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose, 
titanium dioxide, crospovidone, hypromellose, polyethylene glycol, yellow ferric oxide, and red ferric oxide.

What are the most common side effects associated with the use of Levitra?

The most common side effects associated with the use of Levitra include the following: headache, flushing, dyspepsia, nausea and rhinitis. Most of the reported adverse reactions were mild and stopped when the individual discontinued the medication.

• Sensitivity of the eye to sunlight
• High or low blood pressure
• Fainting
• Stiffness in muscles
• Effects on vision
• Erectile disturbances (such as spontaneous or painful erections)

Are there any drug interactions associated with the use of Levitra?

Studies in human liver microsomes showed that Levitra is metabolized primarily by cytochrome P450 (CYP) isoforms 3A4/5, and to a lesser degree by CYP 2C9. Therefore, inhibitors of these enzymes are expected to reduce Levitra clearance.

Cytochrome P450 Inhibitors:

Cimetidine: (400 mg b.i.d.) had no effect on vardenafil bioavailability (AUC) and maximum concentration (Cmax) of vardenafil when co-administered with 20 mg LEVITRA in healthy volunteers.

Ketoconazole: (200 mg once daily) produced a 10-fold increase in vardenafil AUC and a 4-fold increase in Cmax when co-administered with Levitra (5 mg) in healthy volunteers. A 5-mg Levitra dose should not be exceeded when used in combination with 200 mg once daily ketoconazole. Since higher doses of ketoconazole (400 mg daily) may result in higher increases in Cmax and AUC, a single 2.5 mg dose of Levitra should not be exceeded in a 24-hour period when used in combination with ketoconazole 400 mg daily.

Erythromycin: (500 mg t.i.d) produced a 4-fold increase in vardenafil AUCand a 3-fold increase in Cmax when co-administered with Levitra 5 mg in healthy volunteers It is recommended not to exceed a single 5 mg dose of Levitra in a 24-hour period when used in combination with erythromycin.


HIV Protease Inhibitors:

Alpha-blockers: When Levitra 10 or 20 mg was given to healthy volunteers either simultaneously or 6 hours after a 10 mg dose of terazosin, significant hypotension developed in a substantial number of subjects. With simultaneous dosing of Levitra 10 mg and terazosin 10 mg, 6 of 8 subjects experienced a standing systolic blood pressure of less than 85 mm Hg. With simultaneous dosing of Levitra 20 mg and terazosin 10 mg, 2 of 9 subjects experienced a standing systolic blood pressure of less than 85 mm Hg. When Levitra dosing was separated from terazosin 10 mg by 6 hours, 7 of 28 subjects who received 20 mg of Levitra experienced a decrease in standing systolic blood pressure below 85 mm Hg. In a similar study with tamsulosin in healthy volunteers, 1 of 24 subjects dosed with Levitra 20 mg and tamsulosin 0.4 mg separated by 6 hours experienced a standing systolic blood pressure below 85 mm Hg. Two of 16 subjects dosed simultaneously with Levitra 10 mg and tamsulosin 0.4 mg experienced a standing systolic blood pressure below 85 mm Hg. The administration of lower doses of Levitra with alpha blockers has not been completely evaluated to determine if they can be safely administered together. Based on these data, Levitra should not be used in patients on alpha-blocker therapy.

Ritonavir and Indinavir: Upon concomitant administration of 5 mg of Levitra with 600 mg BID ritonavir, the Cmax and AUC of ritonavir were reduced by approximately 20%. Upon administration of 10 mg of Levitra with 800 mg TID indinavir , the Cmax and AUC of indinavir were reduced by 40% and 30%, respectively.

The interaction is a consequence of blocking hepatic metabolism of vardenafil by ritonavir, a highly potent CYP3A4 inhibitor, which also inhibits CYP2C9. Ritonavir significantly prolonged the half-life of vardenafil to 26 hours. Consequently, it is recommended not to exceed a single 2.5 mg Levitra dose in a 72-hour period when used in combination with ritonavir.

Additional Drug Interactions: 

No pharmacokinetic interactions were observed between vardenafil and the following drugs: Maalox, glyburide, warfarin, digoxin, and ranitidine. In the warfarin study, vardenafil had no effect on the prothrombin time or other pharmacodynamic parameters.

Nitrates: The blood pressure lowering effects of sublingual nitrates (0.4 mg) taken 1 and 4 hours after vardenafil and increases in heart rate when taken at 1, 4 and 8 hours were potentiated by a 20 mg dose of Levitra in healthy middle-aged subjects. These effects were not observed when Levitra 20 mg was taken 24 hours before the NTG. Potentiation of the hypotensive effects of nitrates for patients with ischemic heart disease has not been evaluated, and concomitant use of Levitra and nitrates is contraindicated.

Nifedipine: Vardenafil 20 mg, when co-administered with slow-release nifedipine 30 mg or 60 mg once daily, did not affect the relative bioavailability (AUC) or maximum concentration (Cmax) of nifedipine, a drug that is metabolized via CYP3A4. Nifedipine did not alter the plasma levels of Levitra when taken in combination. In these patients whose hypertension was controlled with nifedipine, Levitra 20 mg produced mean additional supine systolic/diastolic blood pressure reductions of 6/5 mm Hg compared to placebo.

Alcohol: Alcohol (0.5 g/kg body weight: approximately 40 mL of absolute alcohol in a 70 kg person) and vardenafil plasma levels were not altered when dosed simultaneously. Levitra (20 mg) did not potentiate the hypotensive effects of alcohol during the 4-hour observation period in healthy volunteers when administered with alcohol (0.5 g/kg body weight).

Aspirin: Levitra (10 mg and 20 mg) did not potentate the increase in bleeding time caused by aspirin (two 81 mg tablets).

Other interactions: Levitra had no effect on the pharmacodynamics of glyburide (glucose and insulin concentrations) and warfarin (prothrombin time or other pharmacodynamic parameters).

Why should Levitra not be used if an individual is taking Nitrates?

Individuals should be counseled that concomitant use of Levitra with nitrates could cause blood pressure to suddenly drop to an unsafe level, resulting in dizziness, syncope, or even a stroke or heart attack.

Why should Levitra not be used if an individual is taking Alpha-blockers?

Physicians should inform their patients that concomitant use of Levitra with alpha-blockers is contraindicated because co-administration can produce hypotension.

Are there individuals that should not take Levitra?

Yes, there are some patient subgroups that have not been studied in clinical trials. Therefore, the use of Levitra is not recommended in the following patients until further studies are completed: or until an individuals physician has approved the use of the medication:

• Unstable angina

• Severe hepatic impairment (Child-Pugh C)

• End stage renal disease requiring dialysis

• Known hereditary degenerative retinal disorders, including retinitis pigmentosa

• Hypotension (resting systolic blood pressure of <90 mm Hg)

• Uncontrolled hypertension (>170/110 mm Hg)

• Recent history of stroke, life-threatening arrhythmia, or myocardial infarction (within the last 6 months); severe cardiac failure

• If you have an allergy (if you're hypersensitive) to vardenafil or any of the other ingredients of Levitra. 

• If you are taking other medications (consult with your physician)

• Cardiovascular complications (stroke, arrhythmia, heart attack, etc.)

• Degenerative eye disease i.e. retinitis pigmentosa

Additional caution should be used in the following individuals:

• Individuals with a physical condition affecting the shape of the penis (i.e. angulation, Peyronie's disease and cavernosal fibrosis, etc.).
• Individuals with an illness that can cause priapism or sustained erections (i.e.  sickle cell disease, multiple myeloma and leukemia, etc.).
• Individuals that have stomach ulcers (i.e. gastric or peptic ulcers).
• Individuals with  a bleeding disorder (i.e. haemophilia).
• Individuals that are using any other treatments for erection difficulties (i.e. Viagra, Cialis).

Will Levitra improve the quality of my erection?

In clinical trials, Levitra provided first time success and reliable improvement in erection quality  for many men with erectile dysfunction (impotence).
In addition, Levitra consistently improved rates of penetration and hardness, as well as, success with intercourse a broad population of men with erectile dysfunction.

Will Levitra produce an erection for hours?

Levitra only enhances a man's natural ability to achieve an erection when you are sexually stimulated. Erections should end following an orgasm or the end of stimulation. In the rare case your erection should lasts for more than 4 hours, please seek immediate medical attention.

Can I take Levitra if I have preexisting cardiovascular complications?

No, some individuals should not take Levitra with preexisting medical conditions. Physicians should discuss with patients the potential cardiac risk of sexual activity for patients with preexisting cardiovascular risk factors.

Does Levitra provide any protection against sexually transmitted diseases?

No, the use of Levitra offers no protection against sexually transmitted diseases. 

Should individuals drive a vehicle or operate heavy machinery while taking Levitra?

Levitra may cause some people to feel dizzy or have an alteration in there vision. These individuals should not drive or operate heavy machinery while taking Levitra.