Why is Levitra prescribed?
Levitra is an oral drug for male impotence, also known as erectile dysfunction (ED). It works by dilating blood vessels in the penis, allowing the inflow of blood needed for an erection.
Most important fact about Levitra
Levitra causes erections only during sexual excitement. It does not work in the absence of arousal and does not increase sexual desire.
How should you take Levitra?
Take one Levitra tablet about one hour before sexual activity, with or without food.
--If you miss a dose...
Take Levitra only before sexual activity, but no more than once a day. Do not take two doses at once.
--Storage instructions...
Store at room temperature.
What side effects may occur?
Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe to continue using Levitra.
• More common side effects may include:
Indigestion, flu-like symptoms, flushing, headache, runny nose, sinus inflammation
This side effects list is not complete. If you have any questions about side effects you should consult your doctor. Report any new or continuing symptoms to your doctor right away.
Why should Levitra not be prescribed?
Do not take Levitra if you are taking any nitrate-based drug, including nitroglycerin patches (Nitro-Dur, Transderm-Nitro), nitroglycerin ointment (Nitro-Bid, Nitrol), nitroglycerin pills (Nitro-Bid, Nitrostat), and isosorbide pills (Dilatrate-SR, Isordil, Sorbitrate). This also includes street drugs known as "poppers," including amyl nitrate and butyl nitrate. Combining Levitra with any of these drugs can cause a dangerous drop in blood pressure.
Likewise, do not take Levitra with certain blood pressure and prostate drugs known as alpha-blockers, including Cardura (doxazosin), Flomax (tamsulosin), Hytrin (terazosin), Minipress (prazosin), and Uroxatral (alfuzosin).
If Levitra gives you an allergic reaction, do not use it again.
Special warnings about Levitra
If you have heart problems severe enough to make sexual activity a danger, you should avoid using Levitra. If you take Levitra and develop cardiac symptoms (for example, dizziness, nausea, and chest pain) during sexual activity, do not continue. Alert your doctor to the problem as soon as possible.
Because Levitra has not been studied in people with cardiovascular disease, it's best to avoid Levitra if you've recently had a stroke or heart failure, or if you've had a heart attack within the past 6 months. Be equally cautious if you have severe high or low blood pressure, heartbeat irregularities, or unstable angina (crushing heart pain that occurs at any time). If you develop angina after taking Levitra, seek medical attention immediately.
If you have severe kidney or liver problems, a bleeding disorder, stomach ulcer, or an inherited retinal disorder such as retinitis pigmentosa, use Levitra with caution. Its safety under these circumstances has not yet been studied.
Rare cases of prolonged and sometimes painful erections (known as priapism) have been reported with Levitra. If you develop an erection that lasts more than 4 hours, seek medical treatment immediately. Otherwise, permanent damage and impotence could result.
If you have a condition that might result in long-lasting erections, such as sickle cell anemia, multiple myeloma (a disease of the bone marrow), or leukemia, use Levitra with caution. Also use caution if you have a genital problem or deformity such as Peyronie's disease.
Remember that Levitra offers no protection from transmission of sexually transmitted diseases, such as HIV, the virus that causes AIDS.
Possible food and drug interactions when taking Levitra
Be sure to check with your doctor about the medications that should never be taken with Levitra, including:

Alpha-blocking drugs prescribed for high blood pressure or prostate problems, including doxazosin (Cardura), tamsulosin (Flomax), terazosin (Hytrin), prazosin (Minipress), and alfuzosin (Uroxatral)
Nitrate-based drugs prescribed for chest pain, such as nitroglycerin patches (Nitro-Dur, Transderm-Nitro), nitroglycerin ointment (Nitro-Bid, Nitrol), nitroglycerin pills (Nitro-Bid, Nitrostat), and isosorbide pills (Dilatrate-SR, Isordil, Sorbitrate)
Street drugs known as "poppers," including amyl nitrate and butyl nitrate
If Levitra is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Levitra with the following:

Other impotence drugs including alprostadil (Caverject), sildenafil (Viagra), and tadalafil (Cialis)
Amiodarone (Pacerone)
Erythromycin (E-Mycin, Ery-Tab, PCE)
Indinavir (Crixivan)
Itraconazole (Sporanox)
Ketoconazole (Nizoral)
Nifedipine (Procardia)
Procainamide (Procanbid)
Quinidine (Quinidex)
Ritonavir (Norvir)
Sotalol (Betapace)
Special information if you are pregnant or breastfeeding
Levitra should not be used by women. Its effects during pregnancy and breastfeeding have not been studied.
Recommended dosage
ADULT MALES
Doses range from 5 milligrams to 20 milligrams, depending on the drug's effect. The recommended starting dose is 10 milligrams for most people. However, if you're 65 or older, the doctor may start you at 5 milligrams.
Take Levitra only before sexual activity. The manufacturer recommends a maximum of one dose per day. However, your doctor may need to lower the dose if you're taking certain drugs that affect the liver, including erythromycin, indinavir (Crixivan), itraconazole (Sporanox), ketoconazole (Nizoral), and ritonavir (Norvir).
If you have moderate liver impairment, the recommended starting dose is 5 milligrams, not to exceed a daily dose of 10 milligrams. If your liver problems are mild, no dosage adjustment is required.
Overdosage
A small study found that a single 120-milligram dose of Levitra caused reversible side effects such as vision changes and back and muscle pain. However, any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.