Maxflow

Each tablet contains Tamsulosin HCl 400 mcg equivalent to Maxflow 367 mcg.

Maxflow HCl, an α₁-adrenoceptor blocking agent, has a high affinity for the α_1A-receptor subtype predominantly present in the human prostate.

Maxflow HCl is (R)-5-[2-[[2-(2-ethoxyphenoxy)ethyl]amino]propyl]-2-methoxybenzenesulfonamide, monohydrochloride. The molecular weight is 444.98.

Maxflow also contains the following excipients: Macrogol 7,000,000 and 8000, magnesium stearate, butylated hydroxytoluene, anhydrous colloidal silica, hypromellose and yellow iron oxide. None of these is derived from animal sources.

Maxflow HCl is sparingly soluble in water (1:85) and slightly soluble in alcohol. It is stable in an acid environment.

Maxflow (Maxflow hydrochloride, USP) capsules are indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). Maxflow capsules are not indicated for the treatment of hypertension.

Maxflow is used to treat men who have symptoms of an enlarged prostate gland, which is also known as benign enlargement of the prostate (benign prostatic hyperplasia or BPH). Benign enlargement of the prostate is a problem that can occur in men as they get older. The prostate gland is located below the bladder. As the prostate gland enlarges, certain muscles in the gland may become tight and get in the way of the tube that drains urine from the bladder. This can cause problems in urinating, such as a need to urinate often, a weak stream when urinating, or a feeling of not being able to empty the bladder completely.

Maxflow helps relax the muscles in the prostate and the opening of the bladder. This may help increase the flow of urine or decrease the symptoms. However, Maxflow will not shrink the prostate. The prostate may continue to get larger. This may cause the symptoms to become worse over time. Therefore, even though Maxflow may lessen the problems caused by enlarged prostate now, surgery still may be needed in the future.

Maxflow is available only with your doctor's prescription.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, Maxflow is used in certain patients with the following medical conditions:

• Ureteric stone (a kidney stone that has moved down into the ureter).

Maxflow capsules 0.4 mg once daily is recommended as the dose for the treatment of the signs and symptoms of BPH. It should be administered approximately one-half hour following the same meal each day. Maxflow capsules should not be crushed, chewed or opened.

For those patients who fail to respond to the 0.4 mg dose after 2 to 4 weeks of dosing, the dose of Maxflow capsules can be increased to 0.8 mg once daily. Maxflow capsules 0.4 mg should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole).

If Maxflow capsules administration is discontinued or interrupted for several days at either the 0.4 mg or 0.8 mg dose, therapy should be started again with the 0.4 mg once-daily dose.

How supplied

Dosage Forms And Strengths

Capsule: 0.4 mg, olive green and orange hard gelatin, imprinted on one side with Maxflow 0.4 mg and on the other side with BI 58

Storage And Handling

Maxflow capsules 0.4 mg are supplied in high density polyethylene bottles containing 100 hard gelatin capsules with olive green opaque cap and orange opaque body. The capsules are imprinted on one side with Maxflow 0.4 mg and on the other side with BI 58.

Maxflow capsules 0.4 mg, 100 capsules (NDC 0597-0058-01)

Store at 25°C (77°F); excursions permitted to 15°C–30°C (59°F–86°F).

Keep Maxflow capsules and all medicines out of reach of children.

Distributed by: Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT 06877 USA. Rev: January 2016

See also:
What is the most important information I should know about Maxflow?

You should not use this medication if you are allergic to Maxflow. Do not take Maxflow with other similar medicines such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), silodosin (Rapaflo), or terazosin (Hytrin).

Maxflow may cause dizziness or fainting, especially when you first start taking it or when you start taking it again. Be careful if you drive or do anything that requires you to be alert. Avoid standing for long periods of time or becoming overheated during exercise and in hot weather. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

If you stop taking Maxflow for any reason, call your doctor before you start taking it again. You may need a dose adjustment.

Maxflow can affect your pupils during cataract surgery. Tell your eye surgeon ahead of time that you are using this medication. Do not stop using Maxflow before surgery unless your surgeon tells you to.

There are many other drugs that can interact with Maxflow. Tell your doctor about all medications you use.

Use Maxflow as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• An extra patient leaflet is available with Maxflow. Talk to your pharmacist if you have questions about this information.
• Take Maxflow by mouth 30 minutes after eating the same meal each day.
• Swallow Maxflow whole. Do not break, crush, chew, or open capsules before swallowing.
• If you miss a dose of Maxflow, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once. If you miss taking Maxflow for several days, contact your doctor for instructions.

Ask your health care provider any questions you may have about how to use Maxflow.

Maxflow is used by men to treat the symptoms of an enlarged prostate (benign prostatic hyperplasia-BPH). It does not shrink the prostate, but it works by relaxing the muscles in the prostate and the bladder. This helps to relieve symptoms of BPH such as difficulty in beginning the flow of urine, weak stream, and the need to urinate often or urgently (including during the middle of the night).

Maxflow belongs to a class of drugs known as alpha blockers.

Do not use this medication to treat high blood pressure.

OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

Maxflow may also be used to help your body "pass," or get rid of, kidney stones through urination. It has also been used to help treat bladder problems in women.

How to use Maxflow

Read the Patient Information Leaflet if available from your pharmacist before you start taking this medication and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth as directed by your doctor, usually once daily, 30 minutes after the same meal each day. Swallow this medication whole. Do not crush, chew, or open the capsules.

The dosage is based on your medical condition and response to treatment.

Maxflow may cause a sudden drop in your blood pressure, which could lead to dizziness or fainting. This risk is higher when you first start taking this drug, after your doctor increases your dose, or if you restart treatment after you stop taking it. During these times, avoid situations where you may be injured if you faint.

Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

If you have not taken this drug for several days, contact your doctor to see if you need to be restarted at a lower dose.

It may take up to 4 weeks before your symptoms improve. Tell your doctor if your condition does not improve or if it worsens.

See also:
What other drugs will affect Maxflow?

Cytochrome P450 Inhibition

Strong And Moderate Inhibitors Of CYP3A4 Or CYP2D6

Maxflow 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 Maxflow 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 Maxflow have not been evaluated.

Concomitant treatment with paroxetine (a strong inhibitor of CYP2D6) resulted in an increase in the Cmax and AUC of Maxflow 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 Maxflow exposure exists when Maxflow 0.4 mg is co-administered with strong CYP3A4 inhibitors in CYP2D6 PMs, Maxflow 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 Maxflow have not been evaluated.

The effects of co-administration of both a CYP3A4 and a CYP2D6 inhibitor with Maxflow capsules have not been evaluated. However, there is a potential for significant increase in Maxflow exposure when Maxflow 0.4 mg is co-administered with a combination of both CYP3A4 and CYP2D6 inhibitors.

Cimetidine

Treatment with cimetidine resulted in a significant decrease (26%) in the clearance of Maxflow hydrochloride, which resulted in a moderate increase in Maxflow hydrochloride AUC (44%).

Other Alpha Adrenergic Blocking Agents

The pharmacokinetic and pharmacodynamic interactions between Maxflow capsules and other alpha adrenergic blocking agents have not been determined; however, interactions between Maxflow capsules and other alpha adrenergic blocking agents may be expected.

PDE5 Inhibitors

Caution is advised when alpha adrenergic blocking agents including Maxflow 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.

Warfarin

A definitive drug-drug interaction study between Maxflow 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 Maxflow capsules.

Nifedipine, Atenolol, Enalapril

Dosage adjustments are not necessary when Maxflow capsules are administered concomitantly with nifedipine, atenolol, or enalapril.

Digoxin And Theophylline

Dosage adjustments are not necessary when a Maxflow capsule is administered concomitantly with digoxin or theophylline.

Furosemide

Maxflow capsules had no effect on the pharmacodynamics (excretion of electrolytes) of furosemide. While furosemide produced an 11% to 12% reduction in Maxflow hydrochloride Cmax and AUC, these changes are expected to be clinically insignificant and do not require adjustment of the Maxflow capsules dosage.

See also:
What are the possible side effects of Maxflow?

The incidence of treatment-emergent adverse events has been ascertained from 6 short-term U.S. and European placebo-controlled clinical trials in which daily doses of Maxflow hydrochloride 0.1-0.8 mg were used. These studies evaluated safety in 1783 patients treated with Maxflow hydrochloride and 798 patients administered placebo. Table 2 below summarizes the treatment emergent adverse events that occurred in ≥2% of patients receiving either Maxflow hydrochloride 0.4-, or 0.8-mg, and at an incidence numerically higher than that in the placebo group during two 13-week U.S. trials conducted in 1487 men.

Table: Treatment Emergent Adverse Events Occurring In ≥2% Of Maxflow hydrochloride Or Placebo Patients in 2 U.S. Short-Term Placebo Controlled Clinical Studies.

The following adverse reactions have been reported during the use of Maxflow hydrochloride: Dizziness, abnormal ejaculation and less frequently (1-2%) headache, asthenia, postural hypotension, palpitations and rhinitis.

Gastrointestinal reactions eg, nausea, vomiting, diarrhea and constipation can occasionally occur. Hypersensitivity reactions eg, rash, pruritus and urticaria can occur occasionally. As with other α-blockers, drowsiness, blurred vision, dry mouth or oedema can occur. Syncope has been reported rarely, and there have been very rare reports of angioedema and priaprism.

During cataract surgery a small pupil situation, known as IFIS, has been associated with therapy of Maxflow hydrochloride during post-marketing surveillance.

Signs and Symptoms of Orthostasis: In the 2 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 ≥1 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 1st dose of double-blind medication, a positive orthostatic test result at 4 hrs post-dose was observed in 7% of patients (37 of 498) who received Maxflow hydrochloride 0.4 mg once daily and in 3% of the patients (8 of 253) who received placebo. At 8 hrs post-dose, a positive orthostatic test result was observed for 6% of the patients (31 of 498) who received Maxflow hydrochloride 0.4 mg once daily and 4% (9 of 250) who received placebo.

At least 1 positive orthostatic test result was observed during the course of the studies for 81 of the 502 patients (16%) in the Maxflow hydrochloride 0.4 mg once daily group, 92 of the 491 patients (19%) in the Maxflow hydrochloride 0.8 mg once daily group and 54 of the 493 patients (11%) in the placebo group.

Because orthostasis was detected more frequently in Maxflow hydrochloride treated patients than in placebo recipients, there is a potential risk of syncope.

Abnormal Ejaculation: Includes ejaculation failure and ejaculation disorder, retrograde and decrease ejaculation. As shown in Table 2, abnormal ejaculation was associated with Maxflow hydrochloride administration and was dose-related.

Withdrawal from these clinical studies of Maxflow hydrochloride 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: Allergic-type reactions eg, skin rash, pruritus, angioedema of tongue, lips and face and urticaria have been reported with positive rechallenge in some cases.

Priapism has been reported rarely. Infrequent reports of palpitations, 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 α-₁-blocker therapy.