From the Guidelines
Flomax (tamsulosin) is contraindicated in patients with a known hypersensitivity to tamsulosin or any component of the formulation, as well as those with severe renal impairment (creatinine clearance less than 10 mL/min) due to lack of clinical studies in this population. Patients with a history of syncope (fainting) with the medication should not restart it. Those taking strong CYP3A4 inhibitors like ketoconazole should also avoid tamsulosin, as these can significantly increase tamsulosin blood levels and side effects 1. Caution is warranted in patients with moderate hepatic impairment, and the medication should be used carefully in those with orthostatic hypotension or who are undergoing cataract surgery due to risk of Intraoperative Floppy Iris Syndrome. While not absolute contraindications, patients should be aware that Flomax may cause dizziness, especially when standing up quickly, and can interact with other alpha-blockers, phosphodiesterase-5 inhibitors, and antihypertensive medications. These contraindications exist because tamsulosin works by relaxing smooth muscles in the prostate and bladder neck, which can affect blood pressure regulation and cause adverse effects in vulnerable populations.
Some key points to consider when prescribing Flomax include:
- Monitoring for orthostatic hypotension, especially in older adults
- Avoiding use in patients with severe renal impairment or those taking strong CYP3A4 inhibitors
- Using caution in patients with moderate hepatic impairment or those undergoing cataract surgery
- Being aware of potential interactions with other medications, such as alpha-blockers, phosphodiesterase-5 inhibitors, and antihypertensive medications.
It's essential to weigh the benefits and risks of Flomax in each patient, considering their individual medical history and current medications, to minimize the risk of adverse effects and ensure the best possible outcome.
From the FDA Drug Label
Tamsulosin Hydrochloride Capsules are contraindicated in patients known to be hypersensitive to tamsulosin hydrochloride or any component of Tamsulosin Hydrochloride Capsules. Do not take Tamsulosin Hydrochloride Capsules if you are allergic to any of its ingredients.
The contraindications for Flomax (tamsulosin) in patients with benign prostatic hyperplasia (BPH) are:
- Hypersensitivity to tamsulosin hydrochloride or any component of Tamsulosin Hydrochloride Capsules
- Allergy to any of the ingredients in Tamsulosin Hydrochloride Capsules 2 2
From the Research
Flomax Contraindications
The contraindications for Flomax (tamsulosin) in patients with benign prostatic hyperplasia (BPH) are not extensively outlined in the provided studies. However, some information can be inferred:
- Tamsulosin is generally well-tolerated, but it can cause adverse effects such as dizziness, abnormal ejaculation, asthenia, postural hypotension, and palpitations 3.
- The drug has a low potential for hypotensive effects or interference with concomitant antihypertensive therapy 3.
- Tamsulosin should be used with caution in patients taking phosphodiesterase 5 inhibitors, such as tadalafil, as it can augment the hypotensive effect of these drugs 4.
- However, tamsulosin 0.4 mg may be given for the treatment of BPH in patients taking tadalafil for erectile dysfunction, as it has little hemodynamic interaction with tadalafil 4.
Special Considerations
Some special considerations for the use of tamsulosin include:
- Patients with a history of orthostatic hypotension or those taking other medications that can cause hypotension should be monitored closely 4, 5.
- Tamsulosin has been shown to be effective and well-tolerated in patients with mild to severe LUTS associated with BPH, as well as in patients with diabetes mellitus and the elderly 3.
- The safety profile of tamsulosin in women and children seems to be generally consistent with the profile in men, although more studies are needed to confirm this 6.
Adverse Effects
Common adverse effects of tamsulosin include: