Cialis

The most common side effects of tadalafil are facial flushing (reddening), headaches, stomach upset, diarrhea, flu-like symptoms, and nausea. Tadalafil also may cause low blood pressure, blurred vision and changes in color vision, and abnormal ejaculation. Tadalafil has been associated with prolonged erections or priapism (painful erections lasting more than 6 hours). Patients should seek immediate medical help if they experience an erection lasting more than 4 hours. Use of tadalafil, most often in patients with pre-existing heart disease, has been associated with chest pain, heart attacks, death, strokes, palpitations, and increased heart rate. Rare cases of sudden loss of hearing have been reported with phosphodiesterase inhibitors such as tadalafil, sometimes associated with ringing in the ears and dizziness. If changes in hearing occur, patients should stop their tadalafil and seek immediate medical attention. Phosphodiesterase-5 inhibitors have been associated rarely with non-arteritic anterior ischemic optic neuropathy (NAION), a condition which causes decreased vision and may lead to blindness. Patients should stop use of all PDE5 inhibitors and seek medical attention if they experience sudden loss of vision in one or both eyes.

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.