DESCRIPTION
Inhibits phosphodiesterase type 5 (PDE5);
enhances erectile function by increasing the amount of cGMP which causes smooth muscle relaxation and increased blood flow into the corpus cavernosum;
improves erectile function for up to 36 hr.
POTENTIAL SIDE EFFECTS
Headache, flushing, dizziness, Back pain / myalgia, dyspepsia, nasal congestion, blurred vision, changes in color vision, diarrhea, pruritus.
CAUTIONS
Seek medical attention if prolonged erection (greater than four hours) occurs.
There is a potential risk of a cardiac event associated with sexual activity in some patients. This drug is not for use in such patients. Discuss these risks with your doctor prior to initiation of therapy.
May require lower doses in reduced kidney or liver function.
Inform your doctor if you have an anatomical deformation of the penis or conditions that may put you at an increased risk for priapism (prolonged, painful erections greater than six hours), including but not limited to sickle cell anemia, multiple myeloma, and leukemia.
Do not use nitrates in any form. See the following website for a list of such drugs (FDA). Check with your pharmacist or doctor before starting a new medication, herbal product or nonprescription drug while taking this drug.
Use with other erectile dysfunction treatments is not recommended.
Tadalafil is not indicated for use in newborns, children, or women.
DRUG INTERACTIONS
Nitrates (see cautions), alpha-blockers (such as doxazosin, terazosin, etc.), antacids, bendroflumethiazide, enalapril, metoprolol, heparin, phenytoin, carbamazepine, phenobarbital, rifampin, antihypertensives, amlodipine, beta-blockers (such as propranolol, etc.), simetidine, diuretics, ketoconazole, itraconazole, erythromycin, protease inhibitors.
This drug is metabolized by a specific set of liver enzymes (cytochrome P450 enzymes 3A4). Several other drugs interfere with these liver enzymes, and thus may increase or decrease the clearance of tadalafil from the body, potentially increasing the risk of side effects or decreasing effectiveness.
When these drugs are given in combination with tadalafil, dosage adjustments may be needed. As these are too numerous to list, you should always check with your doctor or pharmacist prior to starting a new medication, herbal, or nonprescription product.
FOOD INTERACTIONS
Grapefruit juice. Avoid substantial alcohol intake. May be taken with or without food.
HERBAL INTERACTIONS
St. John’s wort
PREGNANCY AND BREAST-FEEDING CAUTIONS
FDA Pregnancy Risk Category B. Not for use in women; not recommended during breast-feeding.
SPECIAL INFORMATION
This medication is to be taken by mouth one hour prior to sexual activity. Do not take with an alpha-blocker (may result in significant low blood pressure). This drug does not protect against sexually transmitted diseases. Do not take more than once daily.
In 2005, the FDA reported a safety alert that described changes in the product labeling for all drugs in this class. Specifically, the changes were based on a small number of post-marketing reports of sudden vision loss, attributed to NAION (non arteritis ischemic optic neuropathy), a condition where blood flow is blocked to the optic nerve. The FDA advises patients to stop taking these medicines, and call a doctor or healthcare provider right away if they experience sudden or decreased vision loss in one or both eyes.
