Cialis (tadalafil) vs. Levitra (vardenafil): What’s the difference?

What is tadalafil? What is vardenafil?

Tadalafil is a phosphodiesterase-5 (PDE5) inhibitor used to treat impotence (the inability to attain or maintain a penile erection) and benign prostatic hyperplasia (BPH). Other PDE5 inhibitors include sildenafil (Viagra) and vardenafil (Levitra). Sexual stimulation that leads to an erection causes the production and release of nitric oxide in the penis, which causes the enzyme guanylate cyclase to produce cyclic guanosine monophosphate (cGMP). cGMP is responsible for increasing and decreasing the size of blood vessels carrying blood to and from the penis and causing an erection. When phosphodiesterase-5 enzyme destroys cGMP, the blood vessels return to their normal size, blood leaves the penis, and the erection ends. Tadalafil prevents PDE5 from destroying cGMP so cGMP stays around longer which leads to a more prolonged erection. It is unclear how tadalafil improves symptoms of BPH, but PDE5 is also present in the muscles of the bladder and the prostate, and it is believed that the relaxation of these muscles may make the passage of urine less difficult by reducing the pressure in the muscle surrounding the opening to the urethra that controls the flow of urine from the bladder.

Vardenafil is a phosphodiesterase-5 (PDE5) inhibitor used to treat impotence, the inability to attain or maintain a penile erection. It has a mechanism of action that is similar to sildenafil (Viagra), and tadalafil (Cialis). Penile erection is caused by the engorgement of the penis with blood that occurs when the blood vessels delivering blood to the penis increase in size and blood vessels carrying blood away from the penis decrease in size. Sexual stimulation that leads to the engorgement and erection causes the production and release of nitric oxide in the penis. Nitric oxide then activates the enzyme guanylate cyclase to produce cyclic guanosine monophosphate (cGMP) that is primarily responsible for increasing and decreasing the size of the blood vessels carrying blood to and from the penis. Vardenafil prevents an enzyme called phosphodiesterase-5 (PDE-5) from destroying cGMP so that cGMP persists longer. The longer cGMP persists, the more prolonged the engorgement of the penis.

What are the side effects of tadalafil and vardenafil?

Tadalafil

The most common side effects of tadalafil are

Vardenafil

The most common side effects of vardenafil are facial flushing (reddening), headaches, stomach upset, diarrhea, flu like symptoms, and nausea. Vardenafil also may cause chest pain, low blood pressure, blurred vision and changes in color vision, abnormal ejaculation and priapism (painful erection lasting more than 6 hours). Patients should seek immediate medical help if they experience an erection lasting more than 4 hours. Rare cases of sudden loss of hearing have been reported with phosphodiesterase inhibitors such as vardenafil, sometimes associated with ringing in the ears and dizziness. If changes in hearing occur, patients should discontinue their vardenafil and seek immediate medical attention.

SLIDESHOW

Erectile Dysfunction (ED) Causes and Treatment See Slideshow

What is the dosage for tadalafil vs. vardenafil?

Tadalafil

For most individuals, the recommended starting dose of tadalafil is 10 mg per day taken before sexual activity (tadalafil for use as needed). Depending on the adequacy of the response or side effects, the dose may be increased to 20 mg or decreased to 5 mg a day. The effect of tadalafil may last up to 36 hours. Individuals who are taking medications that increase the blood levels of tadalafil should not exceed a total dose of 10 mg in 72 hours (See drug interactions). For once daily use without regard to sexual activity the recommended dose is 2.5 to 5 mg daily. Tadalafil should not be taken more than once daily.

The recommended dose for BPH, or BPH and ED is 5 mg daily taken about the same time each day. Tadalafil may be taken with or without food since food does not affect its absorption from the intestine.

The dose of tadalafil may require adjustment for patients with reduced kidney or liver function.

Vardenafil

For most individuals, the recommended dose of vardenafil regular tablets is 10 mg per day taken 60 minutes before intercourse. If there is no response or side effects, the dose may be increased to 20 mg or, if there are side effects, it may be reduced to 5 mg.

Individuals 65 years of age or older should begin therapy with 5 mg.

Individuals who are taking medications that increase the blood levels of vardenafil should start treatment with 2.5 to 5 mg of vardenafil. (See drug interactions.)

Orally disintegrating tablets (ODT) are not interchangeable with regular vardenafil tablets because they are better absorbed and produce higher blood levels than regular tablets. The recommended dosing when using ODT is one tablet 60 minutes before intercourse. Only one tablet should be used per day. It should be placed on the tongue until it disintegrates and should not be swallowed with water.

What drugs interact with tadalafil and vardenafil?

Tadalafil

The breakdown and elimination of tadalafil from the body may be decreased by erythromycin, ketoconazole (Nizoral), itraconazole (Sporanox), indinavir (Crixivan) and ritonavir (Norvir). Therefore, these drugs may increase the levels of tadalafil in the blood. If these drugs are being used at the same time as tadalafil, the dose of tadalafil should be reduced to 10 mg every 72 hours when used as needed or 2.5 mg when used daily in order to avoid side effects from high levels of tadalafil.

Rifampin, carbamazepine (Tegretol, Tegretol XR, Equerto, Carbatrol), phenytoin (Dilantin, Dilantin-125), and phenobarbital may decrease blood levels of tadalafil, possibly reducing the effect of tadalafil.

Tadalafil exaggerates the increases in heart rate and lowering of blood pressure caused by nitrates, for example, nitroglycerin, isosorbide dinitrate (Isordil), isosorbide mononitrate (Imdur, Ismo, Monoket), nitroglycerin (Nitro-Dur, Transderm-Nitro) that are used primarily for treating heart pain (angina). In patients who take nitrates for angina, tadalafil could cause heart pain or possibly even a heart attack by exaggerating the increase in heart rate and the lowering of blood pressure. Therefore, tadalafil should not be used with nitrates.

Tadalafil also exaggerates the blood pressure lowering effects of some alpha-blocking drugs for example, terazosin (Hytrin) that primarily are used for treating high blood pressure or enlargement of the prostate (BPH). Individuals who take these alpha-blockers should be on a stable dose of the alpha-blocker before tadalafil is started. In such situations, tadalafil should be started at the lowest dose. If the patient is already taking tadalafil, the alpha-blocker should be started at the lowest dose. Combining tadalafil with alpha-blockers for treatment of BPH is not recommended.

Tadalafil and alcohol both lower blood pressure. Therefore, combining tadalafil with alcohol may cause excessive drops in blood pressure and cause dizziness, headaches, and increased heart rate.

PDE5 inhibitors may affect platelet function and therefore prolong bleeding. Tadalafil should be used cautiously in patients with bleeding disorders or active ulcers. Tadalafil should not be combined with Adcirca (another form of tadalafil) or other PDE5 inhibitors, for example, vardenafil (Levitra) or sildenafil (Viagra, Revatio).

Vardenafil

The breakdown and elimination of vardenafil from the body is inhibited by erythromycin, clarithromycin (Biaxin), ketoconazole (Nizoral), itraconazole (Sporanox), indinavir (Crixivan), ritonavir (Norvir), atazanavir (Reyataz), grapefruit juice. Therefore, these drugs increase the concentration of vardenafil in the blood and should not be combined with vardenafil. Vardenafil reduces the concentration of ritonavir and indinavir and may reduce the effect these drugs. Vardenafil increases heart rate and also exaggerates blood pressure lowering effects of nitrates (for example, nitroglycerine). In patients with chest pain (angina), particularly those who take nitrates,, vardenafil can cause chest pain by increasing heart rate and lowering blood pressure. Therefore, patients with angina should not use vardenafil. Vardenafil also exaggerates the blood pressure lowering effects of alpha-blocking drugs, for example, terazosin (Hytrin), and should not be used by individuals who also use alpha-blockers. Vardenafil also adds to the blood pressure reducing effect of other medications.

Are tadalafil and vardenafil safe to use while pregnant or breastfeeding?

Tadalafil

Tadalafil is not approved for use in women.
Tadalafil is not approved for women and has not been evaluated in women who are breastfeeding.

Vardenafil

Vardenafil is not approved for use in women.
Vardenafil has not been evaluated in women who are breastfeeding.

QUESTION

Condoms are the best protection from sexually transmitted diseases (STDs). See Answer

Summary

Cialis (tadalafil) and Levitra (vardenafil) are phosphodiesterase-5 (PDE5) inhibitor used to treat impotence (the inability to attain or maintain a penile erection). Tadalafil is also used to treat symptoms of benign prostatic hyperplasia (BPH).

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Medically Reviewed on 7/22/2019
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