From the Guidelines
Flomax (tamsulosin) can cause several side effects, including dizziness, headache, abnormal ejaculation, and orthostatic hypotension, with a higher probability of ejaculatory dysfunction compared to other alpha blockers 1. The most common side effects of Flomax are related to its mechanism of action as an alpha-adrenergic receptor antagonist, which relaxes muscles in the prostate and bladder neck to improve urine flow in men with benign prostatic hyperplasia (BPH) 1. Some key points to consider when taking Flomax include:
- Starting with the recommended dose (usually 0.4 mg once daily) and taking it consistently at the same time each day, preferably after the same meal, to minimize side effects
- Being aware of the potential for "floppy iris syndrome," which can complicate cataract surgery if your ophthalmologist isn't aware you're taking the medication
- Monitoring for severe dizziness, fainting, or persistent side effects, and contacting your healthcare provider immediately if these occur
- Understanding that Flomax may have a slightly different adverse event profile compared to other alpha blockers, such as a lower probability of orthostatic hypotension but a higher probability of ejaculatory dysfunction 1.
From the FDA Drug Label
Possible side effects of Tamsulosin Hydrochloride Capsules may include: Decreased blood pressure when changing positions. Tamsulosin Hydrochloride Capsules may cause a sudden drop in blood pressure upon standing, especially after the first dose or when changing doses Symptoms may include: fainting dizziness lightheadedness Allergic reactions Make your doctor aware of any allergic reactions you may experience while taking Tamsulosin Hydrochloride Capsules. Allergic reactions may include: rash itching hives Rare and more serious allergic reactions may also occur Get medical help right away if you have any of the following reactions: swelling of face, tongue, or throat difficulty breathing blistering of the skin A painful erection that will not go away. Tamsulosin Hydrochloride Capsules can cause a painful erection (priapism), which cannot be relieved by having sex. If this happens, get medical help right away If priapism is not treated, you may not be able to get an erection in the future. Eye problems during cataract or glaucoma surgery. During cataract or glaucoma surgery, a condition called intraoperative floppy iris syndrome (IFIS) can happen if you take or have taken Tamsulosin Hydrochloride Capsules If you need to have cataract or glaucoma surgery, be sure to tell your surgeon if you take or have taken Tamsulosin Hydrochloride Capsules. Common side effects of Tamsulosin Hydrochloride Capsules may include: runny nose dizziness decreased semen
The side effects of Flomax (tamsulosin) may include:
- Decreased blood pressure when changing positions
- Allergic reactions, such as rash, itching, and hives
- Painful erection (priapism)
- Eye problems during cataract or glaucoma surgery
- Common side effects, such as runny nose, dizziness, and decreased semen 2 2
From the Research
Flomax Side Effects
- Flomax, also known as tamsulosin, is an alpha-blocker used to treat lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) 3, 4, 5, 6, 7.
- Common side effects of alpha-blockers, including Flomax, are:
- The incidence of hypotension differs between alpha-blockers, with Flomax having a lower potential to reduce blood pressure and cause symptomatic orthostatic hypotension compared to other alpha-blockers like terazosin and doxazosin 3, 4, 5.
- Flomax has been shown to have a favorable cardiovascular safety profile, with a low incidence of orthostatic hypotension 4, 7.
- However, Flomax has been associated with abnormal ejaculation, which is a common adverse effect, especially when compared to other alpha-blockers like alfuzosin 6, 7.
- The risk of ejaculatory disorders with Flomax is lower compared to silodosin, but higher compared to alfuzosin 6.
- Clinicians should consider these side effects when prescribing Flomax, especially in younger and older patients 6.