Flomax - General Information
Flomax is a selective antagonist at alpha-1A and alpha-1B-adrenoceptors in the prostate, prostatic capsule, prostatic urethra, and bladder neck. At least three discrete alpha1-adrenoceptor subtypes have been identified: alpha-1A, alpha-1B and alpha-1D; their distribution differs between human organs and tissue. Approximately 70% of the alpha1-receptors in human prostate are of the alpha-1A subtype. Blockage of these receptors causes relaxation of smooth muscles in the bladder neck and prostate.
Pharmacology of Flomax
Flomax, an alpha-adrenoceptor blocker with enhanced specificity for the alpha-adrenoceptors of the prostate, is commonly used to treat benign prostatic hyperplasia (BPH).
Flomax for patients
ABOUT FLOMAX CAPSULES
FLOMAX capsules are for use by men only. Flomax capsules are not indicated for use in women.
Please read this leaflet before you start taking FLOMAX capsules. Also, read it each time you renew your prescription, just in case new information has been added. Remember, this leaflet does not take the place of careful discussions with your doctor. You and your doctor should discuss FLOMAX capsules when you start taking your medication and at regular checkups.
Why your doctor has prescribed FLOMAX capsules?
Your doctor has prescribed FLOMAX capsules because you have a medical condition called benign prostatic hyperplasia or BPH. This occurs only in men.
What is BPH?
Benign prostatic hyperplasia is an enlargement of the prostate gland. After age 50, most men develop enlarged prostates. The prostate is located below the bladder. As the prostate enlarges, it may slowly restrict the flow of urine. This can lead to symptoms such as:
ï a weak or interrupted urinary stream
ï a feeling that you cannot empty your bladder completely
ï a feeling of delay or hesitation when you start to urinate
ï a need to urinate often, especially at night
ï a feeling that you must urinate right away
Since cancer of the prostate may cause similar symptoms, you should be evaluated by your doctor to rule out prostate cancer. Your doctor will likely examine your prostate gland manually to detect abnormalities and may measure prostate-specific antigen (PSA) in your blood to help in evaluating for the presence of prostate cancer. FLOMAX capsules do not affect PSA levels.
Treatment Options for BPH
There are three main treatment options for BPH:
ï Program of monitoring or "Watchful Waiting". Some men have an enlarged prostate gland, but no symptoms, or symptoms that are not bothersome. If this applies, you and your doctor may decide on a program of monitoring, including regular checkups, instead of medication or surgery.
ï There are different kinds of medication used to treat BPH. Your doctor has prescribed FLOMAX capsules for you. See "What a FLOMAX capsule does to treat BPH" below.
ï Surgery. Some patients may need surgery. Your doctor can describe several different surgical procedures to treat BPH. Which procedure is best depends on your symptoms and medical condition.
What a FLOMAX capsule does to treat BPH
FLOMAX capsules act by relaxing muscles in the prostate and bladder neck at the site of the obstruction, resulting in improved urine flow and reduced BPH symptoms.
What you need to know while taking FLOMAX (tamsulosin HCI) capsules
ï You must see your doctor regularly.
While taking FLOMAX capsules, you must have regular checkups. Follow your doctor's advice about when to have these checkups.
ï It is important for you to recognize that FLOMAX capsules can cause a sudden drop in blood pressure especially following the first dose or when changing doses of FLOMAX capsules. Such a drop in blood pressure, although rare in occurrence, may be associated with fainting, dizziness, or lightheadedness. Therefore, get up slowly from a chair or bed at any time until you learn how you react to FLOMAX capsules. You should not drive or do any hazardous tasks until you are used to the side effects of FLOMAX capsules. If you begin to feel dizzy, sit down until you feel better. Although these symptoms are unlikely, you should avoid driving or hazardous tasks for 12 hours after the initial dose or after your doctor recommends an increase in dose. If you interrupt your treatment for several days or more, resume treatment at one capsule a day, after consulting with your physician. Other side effects may include sleeplessness, runny nose, or ejaculatory problems. In some cases, side effects may decrease or disappear when you continue to take FLOMAX capsules.
ï Extremely rarely, FLOMAX Capsules and similar medications have caused prolonged, painful erection of the penis, which is unrelieved by sexual intercourse or masturbation. This condition, if untreated, can lead to permanent inability to have an erection. If you have a prolonged erection, call your doctor or go to an Emergency Room as soon as possible.
You should discuss side effects with your doctor before taking FLOMAX capsules and anytime you think you are having a side effect.
How to take FLOMAX capsules
Follow your doctor's advice about how to take FLOMAX capsules. You should take it approximately 30 minutes following the same meal every day.
Do not share FLOMAX capsules with anyone else; it was prescribed only for you.
Do not crush, chew, or open capsules of FLOMAX capsules.
Keep FLOMAX capsules and all medicines out of reach of children.
FOR MORE INFORMATION ABOUT FLOMAX CAPSULES AND BPH, TALK WITH YOUR DOCTOR. IN ADDITION, TALK TO YOUR PHARMACIST OR OTHER HEALTHCARE PROVIDER.
Drug-Drug Interactions: The pharmacokinetic and pharmacodynamic interactions between FLOMAX capsules and other alpha-adrenergic blocking agents have not been determined. However, interactions may be expected and FLOMAX capsules should NOT be used in combination with other alpha-adrenergic blocking agents.
The pharmacokinetic interaction between cimetidine and FLOMAX capsules was investigated. The results indicate significant changes in tamsulosin HCI clearance (26% decrease) and AUC (44% increase). Therefore, FLOMAX capsules should be used with caution in combination with cimetidine, particularly at doses higher than 0.4 mg.
Results from limited in vitro and in vivo drug-drug interaction studies between tamsulosin HCI and warfarin are inconclusive. Therefore, caution should be exercised with concomitant administration of warfarin and FLOMAX capsules.
Tamsulosin capsules are contraindicated in patients known to be hypersensitive to tamsulosin HCI or any component of tamsulosin capsules.
Additional information about Flomax
Flomax Indication: Used in the treatment of signs and symptoms of benign prostatic hyperplasia.
Mechanism Of Action: Flomax is a selective antagonist at alpha-1A and alpha-1B-adrenoceptors in the prostate, prostatic capsule, prostatic urethra, and bladder neck. At least three discrete alpha1-adrenoceptor subtypes have been identified: alpha-1A, alpha-1B and alpha-1D; their distribution differs between human organs and tissue. Approximately 70% of the alpha1-receptors in human prostate are of the alpha-1A subtype. Blockage of these receptors causes relaxation of smooth muscles in the bladder neck and prostate.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Tamsulosin
Synonyms: Not Available
Drug Category: Antineoplastic Agents
Drug Type: Small Molecule; Approved
Absorption: Absorption of tamsulosin HCI from capsules 0.4 mg is essentially complete (>90%) following oral administration under fasting conditions.
Toxicity (Overdose): LD50 = 650 mg/kg (in rats)
Protein Binding: 94%-99%
Biotransformation: Tamsulosin HCI is extensively metabolized by cytochrome P450 enzymes in the liver, however, the pharmacokinetic profile of the metabolites in humans has not been established.
Half Life: 5-7 hours
Dosage Forms of Flomax: Tablet, extended release Oral
Capsule, extended release Oral
Chemical IUPAC Name: 5-[(2R)-2-[2-(2-ethoxyphenoxy)ethylamino]propyl]-2-methoxybenzenesulfonamide
Chemical Formula: C20H28N2O5S
Tamsulosin on Wikipedia: https://en.wikipedia.org/wiki/Tamsulosin
Organisms Affected: Humans and other mammals