Tamsulosin is a medication primarily used to treat symptoms of an enlarged prostate, also known as benign prostatic hyperplasia (BPH). It belongs to a class of drugs called alpha-1 blockers, which work by relaxing the muscles in the prostate and bladder neck, making it easier to urinate. By reducing urinary symptoms such as difficulty urinating, weak stream, and frequent urination, tamsulosin can improve quality of life for individuals with BPH. It's usually taken orally in the form of capsules or tablets, typically once daily.

Tamsulosin (Flomax) is an alpha-adrenergic receptor inhibitor. Since alpha receptors are mostly present in the lower urinary system, tamsulosin primarily causes smooth muscle relaxation in the bladder and prostate. It causes an increase in urinary flow by relaxing the smooth muscles of the lower urinary tract. It is used to treat the following conditions:

• Benign prostatic hyperplasia:
  • It is used in the treatment of signs and symptoms of benign prostatic hyperplasia (BPH)
  • It is not indicated for the treatment of hypertension.
• Off Label Use of Tamsulosin in Adults:
• It is also used in the following conditions:
  • Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) in males;
  • Lower urinary tract symptoms (LUTS) in males;
  • Ureteral calculi expulsion;
  • Ureteral stent-related urinary symptoms, treatment

Tamsulosin (Flomax) dose in Adult

• Tamsulosin is a medicine that helps with problems caused by an enlarged prostate. It works by relaxing muscles around the prostate and bladder, making it easier to pee. You usually take it once a day, either with or without food, depending on the type of tablet or capsule you have. It's important to take it at the same time every day, around 30 minutes after a meal for capsules or at the same time each day for the controlled-release tablet.

Tamsulosin Dose in the treatment of Benign prostatic hyperplasia (BPH): 

• The typical dose of Tamsulosin for treating Benign Prostatic Hyperplasia (BPH) is 0.4 milligrams (mg) once a day. If there's not enough improvement after 2 to 4 weeks, the dose may be increased to 0.8 mg once daily. If you stop taking it for a few days, start again with the initial dose of 0.4 mg once daily. This applies to the capsule form.
• For the controlled-release tablet (Canadian product), the initial and maximum dose is 0.4 mg once daily.

Tamsulosin Dose in the treatment of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) in males (off-label):  

• In males, Tamsulosin is typically prescribed off-label at an initial dose of 0.4 milligrams (mg) once daily, usually in combination with antibiotic therapy.
• The antibiotic treatment is typically given for the initial 6 weeks.
• If there's not enough improvement with this initial therapy, it's recommended to see a urologist for further evaluation and management.

Tamsulosin Dose in the treatment of lower urinary tract symptoms (LUTS) in males (off-label):  

In cases of Bladder outlet obstruction (BOO) and low postvoid residual (PVR):

• The initial dose is typically 0.4 milligrams (mg) once daily.
• In some cases where symptoms of overactive bladder persist, it may be combined with an anticholinergic agent.
• However, it's essential to follow the advice of a healthcare professional regarding the appropriate dosage and combination therapy.

Tamsulosin Dose in the treatment of Ureteral calculi expulsion (off-label):

• Medical Expulsive Therapy (MET) for distal ureteral calculi (stones >5 and ≤10 mm):
  • The typical dose is 0.4 milligrams (mg) taken orally once daily until the stone passes or for up to 4 weeks.
• Adjunctive therapy following shock wave lithotripsy to aid in the clearance of residual stones:
  • The recommended dose is 0.4 mg taken orally once daily. This therapy should be initiated immediately after undergoing shock wave lithotripsy.
  • The duration of therapy may vary, typically ranging from 14 days to 3 months, as determined by your doctor’s based on your individual circumstances and response to treatment.

Tamsulosin Dose in the treatment of Ureteral stent-related urinary symptoms, treatment (off-label):  

• Tamsulosin is typically prescribed at a dose of 0.4 milligrams (mg) once daily.
• Treatment usually begins immediately following the placement of the ureteral stent.
• The duration of therapy can vary, typically ranging from 1 to 6 weeks, depending on the individual's response and the specific circumstances.
• In some cases, it may be combined with an anticholinergic agent for better symptom control.

Tamsulosin (Flomax) dose in Children

Tamsulosin Dose in the treatment of distal stones Nephrolithiasis: 

For Children aged 2 to 4 years:

• Oral administration of either 0.2 mg or 0.4 mg once daily at bedtime.

For Children older than 4 years and adolescents:

• Oral administration of 0.4 mg once daily at bedtime.

• These recommendations are based on available data from studies.
• In one study involving pediatric patients with stones up to 10 mm, those who received Tamsulosin had a higher rate of spontaneous stone passage compared to those who received analgesics alone.
• In another study of pediatric patients with stones up to 12 mm, Tamsulosin administration resulted in a higher expulsion rate, reduced days to expulsion, fewer pain episodes, and reduced need for analgesia compared to placebo.
• Tamsulosin was generally well tolerated, with no reported adverse effects in these studies.
• However, it's important to consult with your doctor for appropriate dosing and management of pediatric nephrolithiasis.

Tamsulosin Dose in the treatment of Primary bladder neck dysfunction: 

In children aged 3 years and older, as well as adolescents:

• The dosing of Tamsulosin is typically initiated at 0.2 mg once daily orally.
• This initial dose can be increased gradually by 0.2 mg increments based on the response to treatment, including improvements in symptoms and urodynamic studies, as well as tolerability.
• The mean effective dose observed in studies is 0.4 mg daily, with the maximum reported daily dose being 0.8 mg.

• These recommendations are based on data from trials evaluating alpha blocker treatment, including studies involving over 50 pediatric patients who received Tamsulosin.
• Treatment with Tamsulosin resulted in improved urine flow rates and decreased post-void residual urine volume.
• These benefits were sustained for at least 3 years, and Tamsulosin was generally well tolerated with no major adverse effects reported.
• However, it's essential to consult with your doctor for appropriate dosing adjustments and monitoring of treatment response in pediatric patients with Primary Bladder Neck Dysfunction.

Tamsulosin (Flomax) Pregnancy Risk Factor: C

• There isn't much information about using tamsulosin to treat kidney stones during pregnancy.
• If a pregnant person needs to get rid of a kidney stone, doctors usually recommend other treatments like stents or ureteroscopy instead.
• These methods are safer and more commonly used in pregnant people to remove kidney stones, according to recommendations from medical experts.

Tamsulosin (Flomax) dose in kidney disease:

• For patient with a creatinine clearance (CrCl) of 10 mL/minute or higher, no adjustment in the dosage of tamsulosin is typically needed.
• For those patients with a creatinine clearance (CrCl) less than 10 mL/minute, the manufacturer's labeling does not provide specific dosage adjustments because this population hasn't been studied.

Tamsulosin (Flomax) dose in Liver disease:

• For patient with mild-to-moderate liver problem, no adjustment in the dosage of tamsulosin is usually necessary.
• For those with severe liver problem, the manufacturer's labeling doesn't provide specific dosage adjustments because this population hasn't been studied.

Common Side Effects of Tamsulosin (Flomax) Include:

• Cardiovascular:
  • Orthostatic Hypotension
• Central Nervous System:
  • Headache
  • Dizziness
• Genitourinary:
  • Ejaculation Failure
• Infection:
  • Infection
• Respiratory:
  • Rhinitis

Less Common Side Effects of Tamsulosin (Flomax) Include:

• Central Nervous System:
  • Drowsiness
  • Insomnia
  • Vertigo
• Endocrine & Metabolic:
  • Loss Of Libido
• Gastrointestinal:
  • Diarrhea
  • Nausea
• Neuromuscular & Skeletal:
  • Weakness
  • Back Pain
• Ophthalmic:
  • Blurred Vision
• Respiratory:
  • Pharyngitis
  • Cough
  • Sinusitis

Contraindications to Tamsulosin Include:

• In Canadian labeling, tamsulosin is contraindicated in individuals who have experienced hypersensitivity reactions such as angioedema, rash, urticaria, pruritus, or respiratory symptoms to tamsulosin or any component of its formulation.
• Additionally, concomitant use of tamsulosin with strong CYP3A4 inhibitors, including ketoconazole, is also contraindicated.
• This means that if someone is taking medications classified as strong CYP3A4 inhibitors, they should not use tamsulosin due to potential interactions and adverse effects.

Warnings and precautions

Angina

• If someone experiences symptoms of angina while taking tamsulosin, it's essential to discontinue the medication and seek medical attention promptly.

Floppy iris syndrome:

• Intraoperative Floppy Iris Syndrome (IFIS) is a condition observed during eye surgeries like cataract or glaucoma procedures.
• It's characterized by a floppy iris that moves excessively during surgery, ongoing narrowing of the pupil despite dilation, and possible prolapse of the iris.
• IFIS has been linked particularly to the use of alpha-blockers, including tamsulosin, even if the medication was stopped several weeks to months before surgery.
• Discontinuing alpha-blocker therapy before eye surgery hasn't been proven to prevent IFIS.
• This condition can increase the risk of complications during and after surgery and may require changes in surgical techniques.
• Patients should inform their eye surgeon about current or past use of alpha-blockers.
• It's not recommended to start tamsulosin therapy in patients planning cataract or glaucoma surgery.

Syncope/orthostatic hypotension:

• Tamsulosin can cause significant drops in blood pressure when standing up, especially with the first dose or if therapy is interrupted for a few days.
• This might lead to fainting, especially if the dosage is rapidly increased or if other blood pressure-lowering medications like vasodilators or PDE-5 inhibitors (such as sildenafil, tadalafil, or vardenafil) are introduced.
• The drop in blood pressure, known as orthostatic hypotension, can happen 4 to 8 hours after taking the medication and may be related to the dose.
• Patients should be careful when starting new therapy or increasing their dosage and should avoid activities like driving or operating heavy machinery until they know how the medication affects them.

Priapism

• Priapism, a prolonged and painful erection unrelated to sexual stimulation, has been linked to tamsulosin use, although it's a rare occurrence.

Allergy to sulfonamide

• Although rare, some individuals with a known allergy to sulfonamide medications have experienced allergic reactions to tamsulosin.
• If a person has had a severe or life-threatening allergic reaction to sulfa drugs in the past, it's advisable to avoid using tamsulosin unless deemed absolutely necessary and under close medical supervision.

Heart failure:

• According to a scientific statement from the American Heart Association, tamsulosin has been identified as a medication that may worsen underlying heart muscle dysfunction, a condition known as heart failure.
• The extent of this effect is considered moderate.

Prostate cancer:

• Before initiating therapy with tamsulosin, it's recommended to screen for prostate cancer to rule out the presence of prostatic carcinoma.
• This proactive approach helps ensure that any potential development of prostate cancer can be detected early and managed appropriately.

Tamsulosin: Drug Interaction

Monitor:

• Blood Pressure
  • Regular monitoring of blood pressure is important, especially during the initial period of treatment and after any dosage adjustments.
  • Watch for signs of orthostatic hypotension, which is a sudden drop in blood pressure when standing up, particularly after the first dose or dosage changes.
• Urinary Symptoms
  • Keep track of urinary symptoms such as difficulty urinating, weak urine stream, frequent urination, and any changes in these symptoms over time.

How to administer Tamsulosin (Flomax)?

• Capsules
  • Take capsules orally, 30 minutes after the same mealtime each day.
  • Swallow the capsules whole; do not crush, chew, or open them.
• Controlled-Release Tablet [Canadian Product]
  • Take the controlled-release tablet orally at the same time each day, with or without food.
  • Swallow the tablet whole; do not crush, chew, or break it before swallowing.

Mechanism of action of Tamsulosin:

• Alpha-Adrenoreceptor Antagonist
  • Tamsulosin works by blocking alpha-adrenoreceptors in the prostate.
  • Smooth muscle tone in the prostate is controlled by these receptors.
  • By blocking these receptors, tamsulosin causes relaxation of smooth muscle in the bladder neck and prostate.
• Improvement of Urine Flow and BPH Symptoms
  • Relaxation of smooth muscle in the bladder neck and prostate leads to improved urine flow.
  • Symptoms of Benign Prostatic Hyperplasia (BPH), such as difficulty urinating and frequent urination, are decreased.
  • Approximately 75% of the alpha-receptors in the prostate are of the alpha subtype, which tamsulosin targets.

Note on Pharmacokinetics

• Pharmacokinetic studies in pediatric patients aged 2 to 16 years have shown that their values are similar to those of adults.

Absorption:

• Tamsulosin is absorbed well, with over 90% of the dose being absorbed into the body.

Distribution

• It has a moderate volume of distribution (V) of approximately 16 liters.

Protein Binding

• Tamsulosin is highly bound to proteins in the blood, primarily to alpha-1 acid glycoprotein (AAG), with binding ranging from 94% to 99%.

Metabolism

• It undergoes extensive metabolism in the liver, primarily via the CYP3A4 and 2D6 enzymes.
• Metabolites are further processed through conjugation to glucuronide or sulfate.

Bioavailability

• The bioavailability of tamsulosin increases by 30% when taken on an empty stomach.
• It reaches steady-state concentrations in the blood by the fifth day of once-daily dosing.

Half-life Elimination

• In healthy volunteers, the half-life of elimination ranges from 9 to 13 hours, while in the target population (presumably individuals with BPH), it is slightly longer, ranging from 14 to 15 hours.

Time to Peak

• Tamsulosin reaches its peak concentration in the blood approximately 4 to 5 hours after ingestion on an empty stomach and 6 to 7 hours after ingestion with food.

Excretion

• The primary route of excretion is through urine, with approximately 76% of the dose being eliminated this way, although less than 10% of it remains unchanged.
• About 21% of the dose is excreted in the feces.

International Brands of Tamsulosin:

• APO-Tamsulosin CR
• Flomax CR
• MYLAN-Tamsulosin
• RATIO-Tamsulosin
• SANDOZ Tamsulosin
• SANDOZ Tamsulosin CR
• TEVA-Tamsulosin
• TEVA-Tamsulosin CR
• Adenorm
• Alna
• Bazetham
• Bestflo
• Comadex
• Contiflo OD
• Curepro XR
• Eziflo
• Flectone XL
• Flomax
• Flomaxtra
• Flomaxtra XL
• Flosin
• Flosure
• Fokusin
• Harnal
• Harnal D
• Harnal OCAS
• Harnalidge D
• Harusin SR
• Inreq
• Josir
• Kirnom
• Libert
• Losiprost
• Lostam
• Lutsnal
• Maxflow
• Maxrin
• Mecir LP
• Mingo
• Omexel LP
• Omic
• Omix Ocas
• Omnexel
• Omnic
• Omnic OCAS
• Omnic Tocas
• Omsal
• Petyme
• Pimax
• Pinexel PR
• Promnix
• Prosta-Tab PR
• Prozelax
• Ranomax
• Sasolin
• Sebrane
• Secotex
• Secotex OCAS
• Sulosin
• Sultam
• Tabphyn MR
• Talusin
• Tamic
• Tamlosin
• Tamlosin SR
• Tamnexyl
• Tamodof
• Tamsin
• Tamsnal SR
• Tamsol
• Tamsu
• Tamsulid
• Tamsulin
• Tamsulo
• Tamsulon
• Tamsustad
• Tamunal
• Tarunal
• Urimax
• Urnal
• Uroflo
• Uroflow
• Urostad
• Urotams SR
• Xalgetz
• Zotan
• Zuantrip

Tamsulosin (Flomax) Brands in Pakistan: