Does Flomax (tamsulosin) cause side effects?
Common side effects of Flomax include
- anemia (decreased red blood cells),
- decreased white blood cells,
- abnormal taste,
- increased triglycerides,
- low blood pressure,
- abdominal pain,
- weight loss,
- muscle pain,
- abnormal ejaculation,
- upper respiratory tract infections, and
Serious side effects of Flomax include
- low blood pressure when standing (orthostatic hypotension),
- prolonged erection (priapism), and
- an eye problem called intraoperative floppy iris syndrome (IFIS).
Drug interactions of Flomax include erythromycin, ketoconazole, paroxetine, cimetidine, ritonavir, lopinavir, and other drugs that reduce the elimination of drugs by liver enzymes because the elimination of Flomax from the body may be reduced by these drugs.
Reduced elimination may lead to increased side effects of Flomax. PDE-5 inhibitors (for example, vardenafil, sildenafil, tadalafil) add to the blood pressure lowering effects of Flomax and may result in severe blood pressure reduction.
What are the important side effects of Flomax (tamsulosin)?
The most common adverse effects of Flomax are
- anemia (decreased red blood cells),
- decreased white blood cells,
- abnormal taste,
- increased triglycerides, and
Other side effects include
- low blood pressure,
- abdominal pain,
- weight loss,
- muscle pain,
- abnormal ejaculation,
- upper respiratory tract infections, and
More serious side effects of Flomax
The following have been observed in male patients during Flomax treatment:
Flomax (tamsulosin) side effects list for healthcare professionals
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reactions rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The incidence of treatment-emergent adverse events has been ascertained from six short-term U.S. and European placebo-controlled clinical trials in which daily doses of 0.1 to 0.8 mg Flomax capsules were used.
These studies evaluated safety in 1783 patients treated with Flomax capsules and 798 patients administered placebo. Table 1 summarizes the treatment-emergent adverse events that occurred in ≥2% of patients receiving either Flomax capsules 0.4 mg or 0.8 mg and at an incidence numerically higher than that in the placebo group during two 13-week U.S. trials (US92-03A and US93-01) conducted in 1487 men.
Table 1: Treatment-Emergent* Adverse
Events Occurring in ≥2% of Flomax Capsules or
Placebo Patients in Two U.S. Short-Term Placebo-Controlled Clinical
|BODY SYSTEM/ ADVERSE EVENT||Flomax CAPSULES GROUPS||PLACEBO|
|BODY AS WHOLE|
|Headache||97 (19.3%)||104 (21.1%)||99 (20.1%)|
|Infection†||45 (9.0%)||53 (10.8%)||37 (7.5%)|
|Asthenia||39 (7.8%)||42 (8.5%)||27 (5.5%)|
|Back pain||35 (7.0%)||41 (8.3%)||27 (5.5%)|
|Chest pain||20 (4.0%)||20 (4.1%)||18 (3.7%)|
|Dizziness||75 (14.9%)||84 (17.1%)||50 (10.1%)|
|Somnolence||15 (3.0%)||21 (4.3%)||8 (1.6%)|
|Insomnia||12 (2.4%)||7 (1.4%)||3 (0.6%)|
|Libido decreased||5 (1.0%)||10 (2.0%)||6 (1.2%)|
|Rhinitis‡||66 (13.1%)||88 (17.9%)||41 (8.3%)|
|Pharyngitis||29 (5.8%)||25 (5.1%)||23 (4.7%)|
|Cough increased||17 (3.4%)||22 (4.5%)||12 (2.4%)|
|Sinusitis||11 (2.2%)||18 (3.7%)||8 (1.6%)|
|Diarrhea||31 (6.2%)||21 (4.3%)||22 (4.5%)|
|Nausea||13 (2.6%)||19 (3.9%)||16 (3.2%)|
|Tooth disorder||6 (1.2%)||10 (2.0%)||7 (1.4%)|
|Abnormal ejaculation||42 (8.4%)||89 (18.1%)||1 (0.2%)|
|Blurred vision||1 (0.2%)||10 (2.0%)||2 (0.4%)|
|*A treatment-emergent adverse event was defined as any
event satisfying one of the following criteria:
The adverse event occurred for the first time after initial dosing with double-blind study medication.
The adverse event was present prior to or at the time of initial dosing with double-blind study medication and subsequently increased in severity during double-blind treatment; or
The adverse event was present prior to or at the time of initial dosing with double-blind study medication, disappeared completely, and then reappeared during double-blind treatment.
†Coding preferred terms also include cold, common cold, head cold, flu, and flu-like symptoms.
‡Coding preferred terms also include nasal congestion, stuffy nose, runny nose, sinus congestion, and hay fever.
Signs And Symptoms Of Orthostasis
- In the two U.S. studies, symptomatic postural hypotension was reported by 0.2% of patients (1 of 502) in the 0.4 mg group, 0.4% of patients (2 of 492) in the 0.8 mg group, and by no patients in the placebo group.
- Syncope was reported by 0.2% of patients (1 of 502) in the 0.4 mg group, 0.4% of patients (2 of 492) in the 0.8 mg group, and 0.6% of patients (3 of 493) in the placebo group.
- Dizziness was reported by 15% of patients (75 of 502) in the 0.4 mg group, 17% of patients (84 of 492) in the 0.8 mg group, and 10% of patients (50 of 493) in the placebo group. Vertigo was reported by 0.6% of patients (3 of 502) in the 0.4 mg group, 1% of patients (5 of 492) in the 0.8 mg group, and by 0.6% of patients (3 of 493) in the placebo group.
- Multiple testing for orthostatic hypotension was
conducted in a number of studies. Such a test was considered positive if it met
one or more of the following criteria:
- (1) a decrease in systolic blood pressure of ≥20 mmHg upon standing from the supine position during the orthostatic tests;
- (2) a decrease in diastolic blood pressure ≥10 mmHg upon standing, with the standing diastolic blood pressure <65 mmHg during the orthostatic test;
- (3) an increase in pulse rate of ≥20 bpm upon standing with a standing pulse rate ≥100 bpm during the orthostatic test; and
- (4) the presence of clinical symptoms (faintness, lightheadedness/lightheaded, dizziness, spinning sensation, vertigo, or postural hypotension) upon standing during the orthostatic test.
- Following the first dose of double-blind medication in Study 1, a positive orthostatic test result at 4 hours post-dose was observed in 7% of patients (37 of 498) who received Flomax capsules 0.4 mg once daily and in 3% of the patients (8 of 253) who received placebo.
- At 8 hours post-dose, a positive orthostatic test result was observed for 6% of the patients (31 of 498) who received Flomax capsules 0.4 mg once daily and 4% (9 of 250) who received placebo (Note: patients in the 0.8 mg group received 0.4 mg once daily for the first week of Study 1).
- In Studies 1 and 2, at least one positive orthostatic test result was observed during the course of these studies for 81 of the 502 patients (16%) in the Flomax capsules 0.4 mg once-daily group, 92 of the 491 patients (19%) in the Flomax capsules 0.8 mg once-daily group, and 54 of the 493 patients (11%) in the placebo group.
- Because orthostasis was detected more frequently in Flomax capsule-treated patients than in placebo recipients, there is a potential risk of syncope.
- Abnormal ejaculation includes ejaculation failure, ejaculation disorder, retrograde ejaculation, and ejaculation decrease.
- As shown in Table 1, abnormal ejaculation was associated with Flomax capsules administration and was dose-related in the U.S. studies.
- Withdrawal from these clinical studies of Flomax capsules because of abnormal ejaculation was also dose-dependent, with 8 of 492 patients (1.6%) in the 0.8 mg group and no patients in the 0.4 mg or placebo groups discontinuing treatment due to abnormal ejaculation.
- No laboratory test interactions with Flomax capsules are known. Treatment with Flomax capsules for up to 12 months had no significant effect on prostate-specific antigen (PSA).
The following adverse reactions have been identified during post-approval use of Flomax capsules. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Decisions to include these reactions in labeling are typically based on one or more of the following factors:
- (1) seriousness of the reaction,
- (2) frequency of reporting, or
- (3) strength of causal connection to Flomax capsules.
Infrequent reports of dyspnea, palpitations, hypotension, atrial fibrillation, arrhythmia, tachycardia, skin desquamation including reports of Stevens-Johnson syndrome, erythema multiforme, dermatitis exfoliative, constipation, vomiting, dry mouth, visual impairment, and epistaxis have been received during the postmarketing period.
What drugs interact with Flomax (tamsulosin)?
Cytochrome P450 Inhibition
Strong And Moderate Inhibitors Of CYP3A4 Or CYP2D6
- Tamsulosin is extensively metabolized, mainly by CYP3A4 and CYP2D6.
- Concomitant treatment with ketoconazole (a strong inhibitor of CYP3A4) resulted in an increase in the Cmax and AUC of tamsulosin by a factor of 2.2 and 2.8, respectively. The effects of concomitant administration of a moderate CYP3A4 inhibitor (e.g., erythromycin) on the pharmacokinetics of Flomax have not been evaluated.
- Concomitant treatment with paroxetine (a strong inhibitor of CYP2D6) resulted in an increase in the Cmax and AUC of tamsulosin by a factor of 1.3 and 1.6, respectively. A similar increase in exposure is expected in CYP2D6 poor metabolizers (PM) as compared to extensive metabolizers (EM).
- Since CYP2D6 PMs cannot be readily identified and the potential for significant increase in tamsulosin exposure exists when Flomax 0.4 mg is co-administered with strong CYP3A4 inhibitors in CYP2D6 PMs, Flomax 0.4 mg capsules should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole).
- The effects of concomitant administration of a moderate CYP2D6 inhibitor (e.g., terbinafine) on the pharmacokinetics of Flomax have not been evaluated.
- The effects of co-administration of both a CYP3A4 and a CYP2D6 inhibitor with Flomax capsules have not been evaluated. However, there is a potential for significant increase in tamsulosin exposure when Flomax 0.4 mg is co-administered with a combination of both CYP3A4 and CYP2D6 inhibitors.
- Treatment with cimetidine resulted in a significant decrease (26%) in the clearance of tamsulosin hydrochloride, which resulted in a moderate increase in tamsulosin hydrochloride AUC (44%).
Other Alpha Adrenergic Blocking Agents
- The pharmacokinetic and pharmacodynamic interactions between Flomax capsules and other alpha adrenergic blocking agents have not been determined; however, interactions between Flomax capsules and other alpha adrenergic blocking agents may be expected.
- Caution is advised when alpha adrenergic blocking agents including Flomax are co-administered with PDE5 inhibitors. Alpha-adrenergic blockers and PDE5 inhibitors are both vasodilators that can lower blood pressure. Concomitant use of these two drug classes can potentially cause symptomatic hypotension.
- A definitive drug-drug interaction study between tamsulosin hydrochloride and warfarin was not conducted. Results from limited in vitro and in vivo studies are inconclusive. Caution should be exercised with concomitant administration of warfarin and Flomax capsules.
Nifedipine, Atenolol, Enalapril
- Dosage adjustments are not necessary when Flomax capsules are administered concomitantly with nifedipine, atenolol, or enalapril.
Digoxin And Theophylline
- Dosage adjustments are not necessary when a Flomax capsule is administered concomitantly with digoxin or theophylline.
- Flomax capsules had no effect on the pharmacodynamics (excretion of electrolytes) of furosemide. While furosemide produced an 11% to 12% reduction in tamsulosin hydrochloride Cmax and AUC, these changes are expected to be clinically insignificant and do not require adjustment of the Flomax capsules dosage.
Flomax (tamsulosin) is an alpha-blocker used to treat men who are having difficulty urinating because of enlarged prostates from benign prostatic hyperplasia (BPH). Common side effects of Flomax include anemia (decreased red blood cells), decreased white blood cells, nausea, vomiting, abnormal taste, increased triglycerides, weakness, low blood pressure, dizziness, fainting, headache, abdominal pain, weight loss, muscle pain, abnormal ejaculation, upper respiratory tract infections, and rash. Flomax is used only in men. Flomax is not prescribed for women and is not intended for use during pregnancy or while breastfeeding.
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Second Source article from The Cleveland Clinic
Prostate Cancer Staging and Survival Rates
The prognosis for prostate cancer, as with any cancer, depends on how advanced the cancer has become, according to established stage designations. The patient's PSA score at diagnosis, as well as their Gleason score (the grading system used to determine the aggressiveness of prostate cancer) determines the prognosis and final stage designation. Prostate cancer has a high survival rate in general, but your chances depend on the stage of the cancer.
Prostatitis (Inflammation of the Prostate Gland)
Prostatitis is an inflammation of the prostate gland. Signs and symptoms of prostatitis include painful or difficulty urinating; fever; chills; body aches; blood in the urine; pain in the rectum, groin, abdomen, or low back; and painful ejaculation or sexual dysfunction. Causes of prostatitis include STDs, bacteria from urinary tract infections, or E. coli. Treatment for prostatitis depends on if it is a bacterial infection or chronic inflammation of the prostate gland.
What Are the First Signs of Prostate Problems?
The first signs and symptoms of prostate disorder usually include problems with urination. Please consult your doctor if you experience any of the signs and symptoms to avoid the worsening of the prostate problems.
Prostatitis vs. BPH (Enlarged Prostate): What Is the Difference?
Prostatitis and BPH (benign prostatic hyperplasia, enlarged prostate gland) are both conditions of the prostate gland. Check out the center below for more medical references on prostate gland conditions, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.
Enlarged Prostate (BPH, Benign Prostatic Hyperplasia)
Benign prostatic hyperplasia (BPH or enlarged prostate) is very common in men over 50 years of age. Half of all men over the age of 50 develop symptoms of BPH, but few need medical treatment. This noncancerous enlargement of the prostate can impede urine flow, slow the flow of urine, create the urge to urinate frequently and cause other symptoms like complete blockage of urine and urinary tract infections. More serious symptoms are urinary tract infections (UTIs) and complete blockage of the urethra, which may be a medical emergency. BPH is not cancer. Not all men with the condition need treatment, and usually is closely monitored if no symptoms are present. Treatment measures usually are reserved for men with significant symptoms, and can include medications, surgery, microwave therapy, and laser procedures. Men can prevent prostate problems by having regular medical checkups that include a prostate exam.
What Are the 5 Warning Signs of Prostate Cancer?
Prostate cancer rarely produces symptoms in the early stage; however, few signs can help in detecting prostate cancer.
Does an Enlarged Prostate Affect a Man Sexually?
An enlarged prostate can cause sexual problems in men. Sexual problems, such as erectile dysfunction or ejaculation problems, may occur in men with noncancerous enlargement of the prostate (benign prostatic hyperplasia or BPH).
Prostate cancer is the most common cancer in men after skin cancer. Risk factors include age, family history, ethnicity, and diet. Prostate cancer is diagnosed by a digital rectal exam, prostate-specific antigen (PSA) test, and prostate biopsy. Symptoms may include frequent need to urinate, incontinence, pain, blood in the urine, fatigue, and more. Prognosis and treatment depend on cancer staging. Watchful waiting, surgery, radiation, cryotherapy, and other management strategies are available. Research and clinical trials strive to find new and better treatments for prostate cancer.
Prostate Cancer Treatment: Focal Therapy and Other Experimental Treatments
Several new and experimental treatments for prostate cancer are under study, including treatments that use ultrasound, lasers, tissue-freezing gas, and new ways of administering radiation. These new methods are types of focal therapy, that is, treatment focused on the cancer cells in the prostate, rather than systemic therapy that administers medications or other treatments to the whole body with the aim of treating the prostate.
Can Prostate Cancer Be Completely Cured?
Prostate cancer is the second most common cancer in men. Due to routine screening of prostate-specific antigen (PSA) levels in the United States, nearly 90% of prostate cancers get detected in early stages. When found early, there are several treatment options available and prostate cancer has a high chance of getting cured.
Prostate Cancer Early Signs and Symptoms
Difficulty with urination – frequency, weak stream, trouble getting started, etc. – is usually the first sign of prostate cancer. But these and other early symptoms of prostatic cancer can also come from benign prostate conditions, so diagnostic testing is important, including PSA tests and digital rectal exam.
Prostate Cancer Facts
Prostate cancer is a leading cause of cancer and cancer death in males; in some men, identifying it early may prevent or delay metastasis and death from prostate cancer. The prostate is a walnut-shaped gland that is a part of the male reproductive system that wraps around the male urethra at it exits the bladder. Prostate cancer is common in men over 50 years of age, with the risk of developing prostate cancer increases with aging.
How Is Prostate Cancer Diagnosed?
Prostate cancer is largely a disease of men over 40, so it’s around this age doctors recommend the first prostate screening. The first exam is a blood test to determine if there are abnormal prostate specific antigen (PSA) levels in your blood – PSA is produced by the prostate. If the PSA is high, your doctor will perform a digital rectal exam, during which the doctor feels your prostate from inside your rectum with a gloved finger. Other diagnostic tests include an endoscopic biopsy of tumor tissue for analysis in a lab.
Early-Stage Prostate Cancer Treatment
If prostate cancer is detected early and appears to be slow-growing, invasive procedures, chemotherapy, radiation and other approaches can sometimes do more harm than good. Many prostate cancer treatments come with side effects, like incontinence or impotence, so it’s in the patient’s interest to put off invasive treatments as long as is medically safe. Active surveillance is where doctors "watch and wait" for changes that could prompt medical intervention.
Prostate Cancer Treatment: Chemotherapy, Bone-Targeted and Immune Therapy
Doctors may introduce chemotherapy and immune therapy if other measures fail to cure a case of prostate cancer. However, unlike with other forms of cancer, chemotherapy isn’t the first choice for early prostate cancer. Immune therapy uses the body's own immune system to attack the prostate tumor, while bone-targeted therapy aims to preserve bone and prevent metastasis.
Prostate Cancer Treatment: Hormonal Therapy
Prostate cancer is highly sensitive to, and dependent on, the level of the male hormone testosterone, which drives the growth of prostate cancer cells. Testosterone belongs to a family of hormones called androgens, and today front-line hormonal therapy for advanced and metastatic prostate cancer is called androgen deprivation therapy (ADT).
Prostate Cancer: Radical Prostatectomy Surgery
Radical prostatectomy, or surgical removal of the entire prostate gland, isn’t typically the first choice in prostate cancer treatment. Sometimes a radical approach is necessary to keep the cancer from metastasizing, however. Some cases are too severe or diagnosed too late for drugs or radiation to have much effect. In these cases, treatment teams may opt for a radical prostatectomy, despite potential side effects like impotence and incontinence.
Where Is the Prostate?
The prostate gland, commonly known as the prostate, is one of the male reproductive organs located just below the bladder, above the penis, and in front of the rectum. It is connected to the penis by a tube (urethra) that empties urine from the bladder. The size and shape of the prostate are similar to a walnut.
Prostate Cancer: Radiation, Brachytherapy and Radiopharmaceuticals
Radiation treatment for prostate cancer is a powerful tool at doctors’ disposal. Using radiation vs. surgery or other invasive treatments to kill cancer cells may still cause side effects, but ideally they are less severe. Radiation therapy can be performed via external beam therapy (EBRT) or the placement of radioactive seeds into the prostate (prostate brachytherapy) or using radioactive drugs (radiopharmaceuticals).
Prostate Infection: Causes, Symptoms, and Remedies
If the prostate gland becomes swollen and tender, it is called prostatitis or prostate infection. The prostate gland is a walnut-shaped organ that lies just below a man's urinary bladder.
When Should You Screen for Prostate Cancer?
Screening for prostate cancer helps detecta tumor early, enabling timely treatment and prevention of any complications. According to the American Cancer Society (ACS), the decision to get screened should be made by men in consultation with their doctor. The doctor needs to counsel the men about the uncertainties involved in the screening process, the risks and potential benefits of getting screened for prostate cancer.
The Early Signs of Prostate Cancer
Prostate cancer in its early stages usually causes no signs and symptoms. Screening can help detect the cancer early.
Treatment & Diagnosis
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- Prostate Cancer FAQs
- Prostate Cancer - New Criteria
- Prostate Cancer Risk May Be Lowered By Vitamin E
- Is Prostate Cancer Genetic?
- What Is the Prostate Cancer TNM Stage?
- What Does Prostate Cancer Do to You?
- How Do You Develop Prostate Cancer?
- What Are the Early Signs of Prostate Cancer?
Medications & Supplements
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Professional side effects and drug interactions sections courtesy of the U.S. Food and Drug Administration.