Cardiovascular Effects

Orthostatic hypotension is a potential complication with α1-blocking medications, and it was tested in a number of FLOMAX trials. Patients were described as having experienced symptomatic hypotension if they exhibited any one of four criteria during the orthostatic test¹:

1. a decrease in systolic blood pressure of ≥20 mm Hg upon standing from the supine position
2. a decrease in diastolic blood pressure of ≥10 mm Hg upon standing, with the standing diastolic blood pressure <65 mm Hg
3. an increase in pulse rate of ≥20 beats per minute (bpm) upon standing, with a standing pulse rate ≥100 bpm
4. the presence of clinical symptoms upon standing (ie, faintness, lightheadedness, dizziness, spinning sensation, vertigo or postural hypotension)

Following the first dose of double-blind medication in the first 13-week trial (US 92-03A) a positive orthostatic test result at 4 hours after dosing was observed in 7% (37/498) of patients taking tamsulosin 0.4 mg and in 3% (8/253) of patients taking placebo. Eight hours after dosing, a positive orthostatic test result was observed in 6% (31/498) of patients taking tamsulosin 0.4 mg and 4% (9/250) of those taking placebo. Thus, no meaningful orthostatic effect was noted with tamsulosin compared with placebo.¹

Because orthostasis was detected more frequently with tamsulosin than with placebo, there is a potential risk of syncope and, therefore, patients beginning treatment with FLOMAX should be cautioned to avoid situations where injury could result should syncope occur.¹

Conclusions

These double-blind, placebo-controlled trials demonstrated that tamsulosin was well tolerated at doses that provided effective relief from the signs and symptoms of BPH.

See the efficacy results from US 92-03A and US 93-01

See long-term safety data for FLOMAX