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Product
Anti-asthmatic Products (Aerocort Inhaler)
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Fincar (Finasteride Tablets)
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Fincar
Finasteride Tablets
COMPOSITION
√ Each film-coated Fincar tablet contains
Finasteride USP… 5 mg
Description
» Finasteride,a synthetic 4-azasteroid compound,is
(synthetic antiandrogen)a specific inhibitorof 5 alpha-reductase type 2,an intracellular enzyme that converts testosterone into
the potent 5 alpha-dihydrotestosterone (DHT).
• • • DHT appears to be the principal androgen responsible for stimulation of prostate growth.
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Pharmacology
Pharmacodynamics
√ The development and enlargement of the prostate gland is dependent on the potent androgen, 5(alpha)-dihydrotestosterone (DHT).
√ Type II 5(alpha)-reductase metabolizes testosterone to DHT in the prostate gland, liver and skin.
√ In man, a single 5-mg oral dose of finasteride produces a rapid reduction in serum DHT concentration, with the maximum effect observed (8) hours after the first dose.
√ The suppression of DHT is maintained throughout the 24-hour dosing interval and with continued treatment.
√ Daily dosing of finasteride at 5 mg/day for up to 4 years has been shown to reduce the serum DHT concentration by approximately 70%.
Pharmacokinetics
Absorption
ø In a study of 15 healthy young subjects, the mean bioavailability of finasteride 5-mg tablets was 63% based on the ratio of area under the curve AUC) relative to an intravenous (IV) reference dose.
ø Maximum finasteride plasma concentration averaged 37 ng/mL and was reached 1-2 hours postdose.
ø Bioavailability of finasteride was not affected by food.
Hormonal Control
€ Two primary androgens in males
€ Testosterone – primary testicular androgen
€ Androstenedione – primary adrenal androgen.
Static and dynamic factors
Static (influenced primarily by DHT)
◊ Prostate size is the most important static factor and it is affected primarily by the inhibition of 5α-reductase.
◊ Patients with 5α-reductase deficiency do not develop BPH.
Dynamic (influenced by a1-adrenergic tone)
◊ Excessive adrenergic tone will cause the urethral lumen to narrow which will lead to flow inhibition.
◊ Urinary retention can lead to UTIs and pyelonephritis.
Symptoms
Obstructive – decrease bladder emptying
• Diminished urine stream, voiding takes longer or is incomplete
• Difficulty initiating urine flow (hesitancy)
• Straining
• Bladder feels full even after voiding.
Irritative (usually occur later in disease)
• Bladder muscle hypertrophies
• Hypersensitive (i.e., easily irritated by urine in the bladder)
• Results in increased frequency and urgency , nocturia
Distribution
ø Approximately 90% of circulating finasteride is bound to plasma proteins.
ø There is a slow accumulation phase for finasteride after multiple dosing.
ø Finasteride has been shown to cross the blood brain barrier.
ø ø But does not appear to distribute preferentially to the CSF.
Metabolism
√ Finasteride is extensively metabolized in the liver, primarily via the cytochrome P450 3A4 enzyme subfamily.
Excretion
√ Mean elimination half-life in plasma was 6 hours .
√ 39% of the dose was excreted in the urine in the form of metabolites
√ 57% was excreted in the feces.
Indications
incar is indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in patients with enlarged prostate.
Dosage & Method of Administration
Fincar is recommended for use in adult males.
ø The recommended dose is 5 mg once a day, with or without meals.
ø Although early improvement may be seen, at least 6-12 months of therapy may be necessary in some patients to assess whether a beneficial response has been achieved.
ø Dose adjustment is not required in geriatric individuals.
Contraindications
• Hypersensitivity to any component of this medication.
• Fincar is not indicated for use in women & children.
• Finasteride use is contraindicated in women when they are or may potentially be pregnant.
Warnings and Precautions
Drug Interactions
• No drug interaction of clinical importance with concomitant use of propranolol, digoxin,theophylline and warfarin has been identified.
Other concomitant therapy
Finasteride was concomitantly used in clinical
studies with
€ Angiotensin-converting enzyme (ACE) inhibitors, analgesics, anti-convulsants, diuretics, calcium channel blockers, cardiac nitrates, non-steroidal anti-inflammatory drugs (NSAIDs), benzodiazepines, H 2 antagonists and quinolone antiinfectives without evidence of clinically significant adverse interactions.
Renal impairment
€ No dosage adjustment is necessary in patients with renal insufficiency.
Hepatic impairment
€ Caution should be used in the administration of Fincar in patients with liver function abnormalities, as finasteride is metabolized extensively in the liver.
Pregnancy
◊ Fincar is not indicated for use in women.
◊ Finasteride use is contraindicated in women when they are or may be pregnant due to the potential risk to the male foetus.
Lactation
◊ It is not known whether finasteride is excreted in human milk.
Paediatric use
◊ Fincar is not indicated for use in pediatric patients.
◊ Safety and effectiveness in paediatric patients have not been established.
Geriatric Use
◊ No dosage adjustment is necessary in the elderly.
◊ Although the elimination rate of finasteride is decreased in the elderly, these findings are of no clinical significance.
Undesirable Effects
√ It is generally well tolerated; adverse reactions usually have been mild and transient.
√ These include impotence, decreased libido, decreased volume of ejaculate, breast tenderness and enlargement, hypersensitivity reactions including lip swelling and skin rash.
Overdose
√ Patients have received single doses of finasteride up to 400 mg and multiple doses of finasteride up to 80 mg/day for ( 3 ) months without adverse effects.
√ Until further experience is obtained, no specific treatment for an overdose with finasteride can be recommended.
Presentation
1 strip………10 tablets
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