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 Adults

• Tamsulosin capsules should be given ~30 minutes following the same meal each day.

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

• Capsule: Initial and Maintenance:
  • 0.4 mg once daily given.
  • If the response is inadequate after 2 to 4 weeks, then increase to 0.8 mg once daily.
  • If therapy is stopped or interrupted for several days, restart with 0.4 mg once daily.
  • The controlled-release tablet is given at 0.4 mg once daily

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

• Oral: Initial:
  • 0.4 mg once daily given in combination with antibiotic treatment
  • an antibiotic is given for the initial 6 weeks
  • If a response to initial therapy is inadequate, referral to a urologist is recommended

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

• Bladder outlet obstruction (BOO) and low postvoid residual (PVR):
  • Oral: Initial:
  • 0.4 mg once daily given
  • It can be combined with an anticholinergic agent if symptoms of an overactive bladder persist

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

• Medical expulsive therapy (MET) to facilitate the passage of lower ureteral calculi:

  • Stones >5 and ≤10 mm: Oral:
    • 0.4 mg once daily given until stone passage occurs or for up to 4 weeks.

• Adjunctive therapy following shock wave lithotripsy to facilitate the clearance of residual stones:

  • 0.4 mg once daily given
  • start therapy immediately after extracorporeal shock wave lithotripsy
  • duration of therapy in trials ranged from 14 days to 3 months

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

• 0.4 mg once daily given

Tamsulosin (Flomax) dose in Children

Dose in the treatment of distal stones Nephrolithiasis: 

• Children 2 to 4 years:

  • Oral: 0.2 or 0.4 mg once daily given at bedtime

• Children >4 years and Adolescents:

  • Oral: 0.4 mg once daily given at bedtime

Dose in the treatment of Primary bladder neck dysfunction: 

• Children ≥3 years and Adolescents:

  • Oral: Initial dose:
    • 0.2 mg once daily given
    • increase by 0.2 mg increments according to response (symptoms and urodynamic studies) and tolerability.
    • The mean effective dose is  0.4 mg daily
    • maximum reported daily dose is 0.8 mg/day.

Tamsulosin (Flomax) Pregnancy Risk Factor: C

• There is insufficient information on the use of Tamsulosin to treat ureteral calculi during pregnancy
• If stone removal is required, other treatments like stents and ureteroscopy are recommended.

Tamsulosin (Flomax) dose in kidney disease:

• CrCl ≥10 mL/minute:

  • No dosage adjustment is required.

• CrCl <10 mL/minute:

  • There are no dosage adjustments given in the manufacturer’s labeling (has not been studied).

Tamsulosin (Flomax) dose in Liver disease:

• Mild-to-moderate impairment:

  • No dosage adjustment is required.

• Severe impairment:

  • There are no dosage adjustments given in the manufacturer’s labeling (has not 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:

• Hypersensitivity to Tamsulosin, or any component of it, can result in angioedema and rash.
• Use with strong CYP3A4 inhibitors (including ketoconazole) concurrently

Warnings and precautions

• Angina

  • Stop if you feel that your symptoms of angina are getting worse.

• Floppy iris syndrome:

  • IFIS was seen in patients undergoing cataract or glaucoma surgery who had been on alpha-blockers. This included tamsulosin.
  • It has not been proven that stopping alpha-blocker therapy before cataract or glaucoma surgery is beneficial.
  • IFIS may increase the likelihood of ocular complications after and during surgery.
  • It might be necessary to modify the surgical procedure. Instruct patients to tell their ophthalmologist about any alpha-blocker or current use before considering eye surgery.
  • Patients with planned cataract surgery or glaucoma are not advised to initiate tamsulosin treatment.

• Syncope/orthostatic hypotension:

  • It may cause significant orthostatic hypotension and syncope, especially with the first dose; anticipate a similar effect if therapy is stopped for a few days, if the dosage is rapidly increased, or if another antihypertensive drug (particularly vasodilators) or a PDE-5 inhibitor (eg, sildenafil, tadalafil, vardenafil) is introduced.
  • The "first dose" of orthostatic hypotension is 4-8 hours after dosing. It may also be dose-related.
  • When initiating new therapies or increasing dosages, patients should be cautious about driving or performing dangerous tasks.

• Priapism

  • Rarely, was Priapism seen in conjunction with drug use.

• Allergy to sulfonamide

  • Rarely, do patients with a sulfa allergy also develop an allergic reaction to Tamsulosin.
  • Avoid using it if the reaction is severe or life-threatening.

• Heart failure:

  • Tamsulosin was found to be an agent that can exacerbate myocardial dysfunction.

• Prostate cancer:

  • Screening for prostatic carcinoma is strongly recommended before beginning therapy. Then, screen regularly.

Tamsulosin: Drug Interaction

Monitor:

• Blood pressure
• urinary symptoms

How to administer Tamsulosin (Flomax)?

• Give capsules 30 minutes after the same mealtime each day.
• Capsules should be swallowed whole
• do not crush, chew, or open.
• The controlled-release tablet should be administered at the same time each day with or without food and should be swallowed whole.

Mechanism of action of Tamsulosin:

• Tamsulosin blocks alpha-adrenoreceptors from the prostate.
• Alpha-adrenoreceptors maintain the tone of the prostate's smooth muscles.
• Blocking them causes relaxation of the bladder neck and prostate, which results in improved urine flow and reduced symptoms of BPH.
• About 75% of alpha-receptors found in the prostate belong to the alpha subtype.

Absorption:

• >90%

Distribution: V :

• 16 L

Protein binding:

• protein binding is 94% to 99%, primarily to alpha-1 acid glycoprotein (AAG)

Metabolism:

• Mainly Hepatic (extensive) via CYP3A4 and 2D6; metabolites undergo extensive conjugation to glucuronide or sulfate

Bioavailability:

• Fasting: 30% increase
• Steady-state: By the fifth day of once-daily dosing

Half-life elimination:

• Healthy volunteers: 9 to 13 hours
• Target population: 14 to 15 hours

Time to peak:

• Fasting: 4 to 5 hours
• With food: 6 to 7 hours

Excretion:

• Via Urine (76%, <10% as unchanged drug); feces (21%)

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: