Flomax Side Effects

Please note - some side effects for Flomax may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Flomax - for the Consumer

Flomax

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Flomax:

Back pain; blurred vision; cough; decreased sexual ability; diarrhea; dizziness; drowsiness; lightheadedness; runny or stuffy nose; sinus inflammation; trouble sleeping; weakness.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fainting; fever, chills, or persistent sore throat; irregular heartbeat; prolonged, painful erection; severe of persistent dizziness.

Flomax Side Effects - for the Professional

Flomax

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 3 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.

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® (tamsulosin hydrochloride) 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:  Abnormal ejaculation includes ejaculation failure, ejaculation disorder, retrograde ejaculation and ejaculation decrease. As shown in Table 3, 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.

Post-Marketing Experience

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. Allergic-type reactions such as skin rash, urticaria, pruritus, angioedema and respiratory symptoms have been reported with positive rechallenge in some cases. Priapism has been reported rarely. Infrequent reports of palpitations, hypotension, skin desquamation, constipation and vomiting have been received during the post-marketing period.

During cataract surgery, a variant of small pupil syndrome known as Intraoperative Floppy Iris Syndrome (IFIS) has been reported in association with alpha-1 blocker therapy.

Side Effects by Body System

Nervous system

In one case report, seizure frequency increased in a patient with medial temporal lobe seizures following initiation of tamsulosin treatment. Prior to the use of tamsulosin, the patient experienced 3 to 4 seizures per year. In the first 3 months after starting tamsulosin, seizures were appearing twice a month and by the fourth month of treatment the patient had 3 seizures in one day. Following withdrawal of tamsulosin, seizure frequency returned to baseline.

Nervous system side effects are among the most common and include headache in 4% to 20%, asthenia in 1% to 8%, dizziness in 5% to 15%, somnolence in 0% to 4%, and insomnia in 1% to 2% of patients. (These side effects were also noted among patients treated with placebo in controlled trials, but occurred more often among patients treated with tamsulosin.) According to one case report, tamsulosin caused exacerbation of seizures in a patient with a history of seizures.

Genitourinary

Abnormal ejaculation includes ejaculation failure, ejaculation disorder, retrograde ejaculation and ejaculation decrease. In controlled studies, abnormal ejaculation was associated with the use of tamsulosin and was dose-related. The results of one study suggest that intermittent use of tamsulosin may allow for improvement in abnormal ejaculation.

Genitourinary complaints include abnormal (retrograde or decreased volume) ejaculation among 8% (0.4 mg) to 18% (0.8 mg) of male patients. The occurrence of abnormal ejaculation among males who were given placebo in controlled trials averaged 0.2%. Other genitourinary side effects have included impotence (2.9%) and rare cases of urinary retention and priapism.

Respiratory

Respiratory system side effects include rhinitis in 1% to 18%, pharyngitis in 5%, increased cough in 4%, and sinusitis in 3% of patients. In controlled studies, these side effects were also noted in similar but slightly lower incidences among patients who were treated with placebo.

Musculoskeletal

Musculoskeletal complaints--back or chest pains--were reported among 4% to 8% of patients in controlled trials, compared with 4% to 7% among patients who were treated with placebo.

Cardiovascular

Rarely, flushing and tachycardia have been associated with the use of tamsulosin.

Cardiovascular side effects including rare occurrences of orthostatic hypotension have been reported. In two US studies, symptomatic postural hypotension was reported by 0.2% (0.4 mg), 0.4% (0.8 mg), and 0% (placebo) of patients. Syncope was reported by 0.2%, 0.4%, and 0.6% of patients in the above groups, respectively. Because of the risk of syncope, it is recommended that patients be warned against situations where injury could result were syncope to occur.

Gastrointestinal

Gastrointestinal side effects include diarrhea in 5% and nausea in 3% of patients. In controlled studies, these side effects were also noted in similar but slightly lower incidences among patients who were treated with placebo. Rarely, constipation, gastric pain, dysphagia, and anorexia have been associated with the use of tamsulosin.

Ocular

Although the overall prevalence of intraoperative floppy iris syndrome (IFIS) is 1% to 2%, the incidence of IFIS associated with the use of tamsulosin ranges from 43% to 63%. Most reports were in patients treated with an alpha-1 blocker at the time IFIS occurred, but in some instances the alpha-1 blocker had been stopped prior to surgery. The manufacturer recommends that male patients be questioned to determine whether or not they have taken tamsulosin or other alpha-1 blockers prior to being considered for cataract surgery. If it is determined that the patient has taken an alpha-1 blocker, the patient's ophthalmologist should be prepared for possible modifications to their surgical technique that may be necessary should IFIS be observed during the procedure.

Ocular side effects including amblyopia have been reported in 0.2% of men given 0.4 mg, 2% of men given 0.8 mg, and in 0.4% of men who were given placebo.

Intraoperative Floppy Iris Syndrome (IFIS) has been observed in some patients undergoing phacoemulsification cataract surgery while being treated with alpha-1 blockers including tamsulosin.

Hepatic

Hepatic side effects including rare isolated instances of elevated liver function tests have been associated with the use of tamsulosin.

General

General side effects unrelated to a particular organ system include a flu-like syndrome or infection in approximately 2% of patients. (Similar incidences were observed among patients who were treated with placebo in controlled trials.)

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