As with other alpha-1-blockers, reduction in blood pressure can occur in individual cases during treatment with Tamsulosin HCl, as a result of which, very rarely, syncope can occur. At the first signs of orthostatic hypotension (dizziness, weakness), the patient should sit or lie down until the symptoms have been disappeared.
Before therapy with Tamsulosin HCl is initiated, the patient should be examined in order to exclude the presence of other conditions which can cause the same symptoms as benign prostatic hyperplasia. Digital rectal examination and, when necessary, determination of prostate specific antigen (PSA) should be performed before treatment and at regular intervals afterwards.
Patients with end stage renal disease (creatinine clearance <10 mL/min/1.73 m2) should be approached with caution as these patients have not been studied.
Patients should be advised about the possibility of priapism as a result of treatment with Tamsulosin and other similar medications. Patients should be informed that this reaction is extremely rare, but if not brought to immediate medical attention, can lead to permanent erectile dysfunction (impotence).
Intra-operative Floppy Iris Syndrome (IFIS) has been observed during cataract surgery in some patients taking or who have previously been treated with alpha-1 adrenoceptor antagonists.