Avodart (Dutasteride) 0.5 mg - Uses, Dosage, Side effects

Dutasteride is a medication primarily used to treat benign prostatic hyperplasia (BPH), a condition where the prostate gland enlarges and causes urinary symptoms such as difficulty urinating. It is also sometimes prescribed to treat male pattern baldness (androgenetic alopecia).

Dutasteride works by inhibiting the enzyme 5-alpha reductase, which converts testosterone into dihydrotestosterone (DHT). DHT is implicated in the growth of the prostate gland and the miniaturization of hair follicles in androgenetic alopecia. By reducing DHT levels, dutasteride can help alleviate symptoms of BPH and slow down hair loss.

Avodart (Dutasteride) inhibits the activation of testosterone. It is used in the treatment of benign prostatic hyperplasia and baldness in men (androgenic alopecia).

Dutasteride (Avodart) Uses:

  • Benign Prostatic Hyperplasia (BPH):
    • It is used in the symptomatic treatment of benign prostatic hyperplasia (BPH) as monotherapy or in combination with tamsulosin to improve the lower urinary tract obstructive symptoms, prevent the development of acute urinary retention, and to reduce the risk of need for prostatic surgery.
  • Limitations of use: It is not approved for the prevention of prostate cancer.
  • Off-Label Use of Dutasteride in Adults:
    • Male pattern baldness

Dutasteride Adult dose:

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

  • For treating enlarged prostate (BPH) in men, the usual dose of dutasteride is 0.5 milligrams taken by mouth once a day.
  • It can be taken alone or together with another medication called tamsulosin.

Use in Children:

It's use is contraindicated in children.

Pregnancy Risk Factor X

  • Dutasteride has been found to cause abnormalities in the development of male genitalia in animal studies, which poses a risk to pregnancies (Pregnancy Risk Factor X).
  • It's not meant to be used by women.
  • Pregnant women should especially avoid handling crushed or broken tablets of dutasteride and should also steer clear of semen from male partners who are taking the medication, as it could potentially cause harm to the developing fetus.

Dutasteride use during breastfeeding:

  • It's uncertain whether dutasteride passes into breast milk, so its effects on nursing infants are unknown.
  • Therefore, women who are breastfeeding should avoid using dutasteride.
  • Additionally, the medication is not recommended for women who could become pregnant because of the potential risks it poses to a developing fetus.

Dutasteride (Avodart) Dose in Kidney disease:

Adjustment in the dose is not necessary in patients with kidney disease (as the drug is metabolized in the liver).

Dutasteride (Avodart) Dose in Liver disease:

  • The manufacturer's instructions do not include specific dosage adjustments for individuals with liver impairment since this hasn't been thoroughly studied.
  • Dutasteride is mainly broken down by the liver, so its levels in the body might increase in people with liver problems.
  • However, studies have shown that even higher doses of the medication generally don't lead to more side effects.

Side Effects of Dutasteride (Avodart):

  • Endocrine & Metabolic:
    • Decreased Libido
    • Gynecomastia Including
      • Breast Tenderness
      • Breast Enlargement
    • Increased Luteinizing Hormone
    • Increased Testosterone Level
    • Increased Thyroid Stimulating Hormone Level
  • Genitourinary:
    • Impotence
    • Ejaculatory Disorder
  • Hematologic & Oncologic:
    • Prostate Cancer High Grade

Contraindications to Dutasteride (Avodart):

  • Dutasteride should not be used in individuals who have a significant allergic reaction to dutasteride itself, other medications in the same class (like finasteride), or any ingredient in the formulation.
  • It's not recommended for use in children, and women who could become pregnant should avoid it due to potential risks to the fetus.

Warnings and Precautions

Diminished urinary flow:

  • Patients with significant difficulties in urination, such as a large amount of urine left in the bladder after urination or severely reduced urine flow, should be closely monitored if considering dutasteride therapy.
  • In some cases, these patients may not be suitable candidates for dutasteride treatment due to the risk of urinary obstruction.
  • Therefore, careful assessment and monitoring are essential before starting dutasteride therapy in such individuals.

Hepatic impairment:

  • Dutasteride should be used cautiously in individuals with liver problems.
  • If someone has hepatic impairment, their liver may not metabolize dutasteride as effectively, which could lead to higher levels of the medication in the body.

Prostate cancer:

  • In studies comparing 5-alpha-reductase inhibitors (5-ARIs) like dutasteride to a placebo, these medications have been found to lower the overall risk of developing prostate cancer.
  • However, it's important to note that there has been an observed increase in the occurrence of high-grade prostate cancers among individuals taking 5-ARIs.
  • Despite these findings, 5-ARIs are not approved in the United States or Canada for the prevention of prostate cancer.

Dutasteride: Drug Interaction

Note: Drug Interaction Categories:

  • Risk Factor C: Monitor When Using Combination
  • Risk Factor D: Consider Treatment Modification
  • Risk Factor X: Avoid Concomitant Use

Risk Factor C (Monitor therapy)

CYP3A4 Inhibitors (Strong)

May increase the serum concentration of Dutasteride.

Monitoring parameters:

Relief of Benign Prostatic Hyperplasia (BPH):

  • Objective Signs: Dutasteride can help improve various symptoms of BPH, such as:
    • Better Urinary Flow: It may make it easier to start urinating and reduce interruptions during urination.
    • Reduced Urgency: Dutasteride might lessen the urgent need to urinate.
    • Easier Micturition: It could relieve difficulties or discomfort during urination.
  • Subjective Signs: Patients may notice relief from bothersome BPH symptoms, making urination more comfortable and less frequent.

PSA Monitoring:

  • Baseline PSA Level: After about 3 months of dutasteride therapy, it's recommended to establish a new baseline PSA level.
  • Periodic Monitoring: Healthcare providers should periodically monitor PSA levels thereafter. This helps track any changes and ensures proper management of prostate health.

How to administer Dutasteride (Avodart)?

  • Meal Timing: Dutasteride can be taken with or without meals. There's no need to adjust based on food intake.
  • Swallowing Instructions: The capsule should be swallowed whole, not chewed or opened. Opening the capsule can cause irritation in the mouth and throat (oropharyngeal irritation).
  • Handling Precautions for Pregnant Women:
    • Avoid Contact: Women who are pregnant or capable of becoming pregnant should not handle or come into contact with dutasteride capsules.
    • Risk Awareness: This precaution is important to prevent potential harm to the developing fetus if the medication is absorbed through the skin.

Mechanism of action of Dutasteride (Avodart):

  • Dutasteride is a medication that structurally resembles testosterone and belongs to a class known as 4-azo analogs.
  • It works by competitively and selectively inhibiting two types of the enzyme 5-alpha-reductase: type 1 found in skin and liver, and type 2 found in reproductive tissues.
  • By doing so, it blocks the conversion of testosterone into dihydrotestosterone (DHT), a potent form of testosterone.
  • This inhibition significantly reduces the levels of DHT in the bloodstream, leading to various therapeutic effects such as the treatment of benign prostatic hyperplasia (BPH) and male pattern baldness.

Absorption:

  • Dutasteride can be absorbed through the skin when handling its capsules.

Distribution:

  • Volume: Dutasteride has a large distribution volume in the body, ranging from 300 to 500 liters.
  • Partitioning: Approximately 12% of dutasteride concentrations in the bloodstream are found in semen.

Protein Binding:

  • Dutasteride is highly bound to proteins:
    • 99% to albumin
    • Approximately 97% to alpha-acid glycoprotein
    • More than 96% to semen protein

Metabolism:

  • Route: Dutasteride undergoes hepatic metabolism primarily through the CYP3A4 and CYP3A5 enzymes.
  • Metabolites: It forms several metabolites, including 6-hydroxydutasteride, which has similar activity to the parent compound, and 4'-hydroxydutasteride and 1,2-dihydrodutasteride, which are less potent in vitro.

Bioavailability:

  • Dutasteride's bioavailability is approximately 60%, with a range of 40% to 94%.

Elimination:

  • Half-life: The terminal elimination half-life of dutasteride is around 5 weeks.
  • Time to Peak: It reaches peak concentration in the bloodstream approximately 2-3 hours after administration.

Excretion:

  • Feces: About 40% of the administered dose is excreted in the feces, primarily as metabolites, while around 5% is excreted as unchanged drug.
  • Urine: Less than 1% of the administered dose is excreted unchanged in the urine.
  • Unaccounted Dose: Approximately 55% of the administered dose remains unaccounted for.

International Brands of Dutasteride:

  • ACT Dutasteride
  • APO-Dutasteride
  • AURO-Dutasteride
  • MED-Dutasteride
  • MINT-Dutasteride
  • PMS-Dutasteride
  • RIVA-Dutasteride
  • SANDOZ Dutasteride
  • TEVA-Dutasteride
  • Armonia
  • Avidart
  • Avodart
  • Avolve
  • Bengiride
  • Duagen
  • Duavo
  • Duprost
  • Dutagen
  • Dutamax
  • Dutamex
  • Dutasia
  • Dutaslow
  • Dutesmol
  • Neodart
  • Prostasil
  • Prostatex
  • Quedute
  • Terod
  • Urodart
  • Zagallo

Dutasteride Brand Names in Pakistan:

Dutasteride Capsules 0.5 mg

Avodart

Glaxosmithkline

Dutasteride is a medication primarily used to treat benign prostatic hyperplasia (BPH), a condition where the prostate gland enlarges and causes urinary symptoms such as difficulty urinating. It is also sometimes prescribed to treat male pattern baldness (androgenetic alopecia).

Dutasteride works by inhibiting the enzyme 5-alpha reductase, which converts testosterone into dihydrotestosterone (DHT). DHT is implicated in the growth of the prostate gland and the miniaturization of hair follicles in androgenetic alopecia. By reducing DHT levels, dutasteride can help alleviate symptoms of BPH and slow down hair loss.

Avodart (Dutasteride) inhibits the activation of testosterone. It is used in the treatment of benign prostatic hyperplasia and baldness in men (androgenic alopecia).

Dutasteride (Avodart) Uses:

  • Benign Prostatic Hyperplasia (BPH):
    • It is used in the symptomatic treatment of benign prostatic hyperplasia (BPH) as monotherapy or in combination with tamsulosin to improve the lower urinary tract obstructive symptoms, prevent the development of acute urinary retention, and to reduce the risk of need for prostatic surgery.
  • Limitations of use: It is not approved for the prevention of prostate cancer.
  • Off-Label Use of Dutasteride in Adults:
    • Male pattern baldness

Dutasteride Adult dose:

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

  • For treating enlarged prostate (BPH) in men, the usual dose of dutasteride is 0.5 milligrams taken by mouth once a day.
  • It can be taken alone or together with another medication called tamsulosin.

Use in Children:

It's use is contraindicated in children.

Pregnancy Risk Factor X

  • Dutasteride has been found to cause abnormalities in the development of male genitalia in animal studies, which poses a risk to pregnancies (Pregnancy Risk Factor X).
  • It's not meant to be used by women.
  • Pregnant women should especially avoid handling crushed or broken tablets of dutasteride and should also steer clear of semen from male partners who are taking the medication, as it could potentially cause harm to the developing fetus.

Dutasteride use during breastfeeding:

  • It's uncertain whether dutasteride passes into breast milk, so its effects on nursing infants are unknown.
  • Therefore, women who are breastfeeding should avoid using dutasteride.
  • Additionally, the medication is not recommended for women who could become pregnant because of the potential risks it poses to a developing fetus.

Dutasteride (Avodart) Dose in Kidney disease:

Adjustment in the dose is not necessary in patients with kidney disease (as the drug is metabolized in the liver).

Dutasteride (Avodart) Dose in Liver disease:

  • The manufacturer's instructions do not include specific dosage adjustments for individuals with liver impairment since this hasn't been thoroughly studied.
  • Dutasteride is mainly broken down by the liver, so its levels in the body might increase in people with liver problems.
  • However, studies have shown that even higher doses of the medication generally don't lead to more side effects.

Side Effects of Dutasteride (Avodart):

  • Endocrine & Metabolic:
    • Decreased Libido
    • Gynecomastia Including
      • Breast Tenderness
      • Breast Enlargement
    • Increased Luteinizing Hormone
    • Increased Testosterone Level
    • Increased Thyroid Stimulating Hormone Level
  • Genitourinary:
    • Impotence
    • Ejaculatory Disorder
  • Hematologic & Oncologic:
    • Prostate Cancer High Grade

Contraindications to Dutasteride (Avodart):

  • Dutasteride should not be used in individuals who have a significant allergic reaction to dutasteride itself, other medications in the same class (like finasteride), or any ingredient in the formulation.
  • It's not recommended for use in children, and women who could become pregnant should avoid it due to potential risks to the fetus.

Warnings and Precautions

Diminished urinary flow:

  • Patients with significant difficulties in urination, such as a large amount of urine left in the bladder after urination or severely reduced urine flow, should be closely monitored if considering dutasteride therapy.
  • In some cases, these patients may not be suitable candidates for dutasteride treatment due to the risk of urinary obstruction.
  • Therefore, careful assessment and monitoring are essential before starting dutasteride therapy in such individuals.

Hepatic impairment:

  • Dutasteride should be used cautiously in individuals with liver problems.
  • If someone has hepatic impairment, their liver may not metabolize dutasteride as effectively, which could lead to higher levels of the medication in the body.

Prostate cancer:

  • In studies comparing 5-alpha-reductase inhibitors (5-ARIs) like dutasteride to a placebo, these medications have been found to lower the overall risk of developing prostate cancer.
  • However, it's important to note that there has been an observed increase in the occurrence of high-grade prostate cancers among individuals taking 5-ARIs.
  • Despite these findings, 5-ARIs are not approved in the United States or Canada for the prevention of prostate cancer.

Dutasteride: Drug Interaction

Note: Drug Interaction Categories:

  • Risk Factor C: Monitor When Using Combination
  • Risk Factor D: Consider Treatment Modification
  • Risk Factor X: Avoid Concomitant Use

Risk Factor C (Monitor therapy)

CYP3A4 Inhibitors (Strong)

May increase the serum concentration of Dutasteride.

Monitoring parameters:

Relief of Benign Prostatic Hyperplasia (BPH):

  • Objective Signs: Dutasteride can help improve various symptoms of BPH, such as:
    • Better Urinary Flow: It may make it easier to start urinating and reduce interruptions during urination.
    • Reduced Urgency: Dutasteride might lessen the urgent need to urinate.
    • Easier Micturition: It could relieve difficulties or discomfort during urination.
  • Subjective Signs: Patients may notice relief from bothersome BPH symptoms, making urination more comfortable and less frequent.

PSA Monitoring:

  • Baseline PSA Level: After about 3 months of dutasteride therapy, it's recommended to establish a new baseline PSA level.
  • Periodic Monitoring: Healthcare providers should periodically monitor PSA levels thereafter. This helps track any changes and ensures proper management of prostate health.

How to administer Dutasteride (Avodart)?

  • Meal Timing: Dutasteride can be taken with or without meals. There's no need to adjust based on food intake.
  • Swallowing Instructions: The capsule should be swallowed whole, not chewed or opened. Opening the capsule can cause irritation in the mouth and throat (oropharyngeal irritation).
  • Handling Precautions for Pregnant Women:
    • Avoid Contact: Women who are pregnant or capable of becoming pregnant should not handle or come into contact with dutasteride capsules.
    • Risk Awareness: This precaution is important to prevent potential harm to the developing fetus if the medication is absorbed through the skin.

Mechanism of action of Dutasteride (Avodart):

  • Dutasteride is a medication that structurally resembles testosterone and belongs to a class known as 4-azo analogs.
  • It works by competitively and selectively inhibiting two types of the enzyme 5-alpha-reductase: type 1 found in skin and liver, and type 2 found in reproductive tissues.
  • By doing so, it blocks the conversion of testosterone into dihydrotestosterone (DHT), a potent form of testosterone.
  • This inhibition significantly reduces the levels of DHT in the bloodstream, leading to various therapeutic effects such as the treatment of benign prostatic hyperplasia (BPH) and male pattern baldness.

Absorption:

  • Dutasteride can be absorbed through the skin when handling its capsules.

Distribution:

  • Volume: Dutasteride has a large distribution volume in the body, ranging from 300 to 500 liters.
  • Partitioning: Approximately 12% of dutasteride concentrations in the bloodstream are found in semen.

Protein Binding:

  • Dutasteride is highly bound to proteins:
    • 99% to albumin
    • Approximately 97% to alpha-acid glycoprotein
    • More than 96% to semen protein

Metabolism:

  • Route: Dutasteride undergoes hepatic metabolism primarily through the CYP3A4 and CYP3A5 enzymes.
  • Metabolites: It forms several metabolites, including 6-hydroxydutasteride, which has similar activity to the parent compound, and 4'-hydroxydutasteride and 1,2-dihydrodutasteride, which are less potent in vitro.

Bioavailability:

  • Dutasteride's bioavailability is approximately 60%, with a range of 40% to 94%.

Elimination:

  • Half-life: The terminal elimination half-life of dutasteride is around 5 weeks.
  • Time to Peak: It reaches peak concentration in the bloodstream approximately 2-3 hours after administration.

Excretion:

  • Feces: About 40% of the administered dose is excreted in the feces, primarily as metabolites, while around 5% is excreted as unchanged drug.
  • Urine: Less than 1% of the administered dose is excreted unchanged in the urine.
  • Unaccounted Dose: Approximately 55% of the administered dose remains unaccounted for.

International Brands of Dutasteride:

  • ACT Dutasteride
  • APO-Dutasteride
  • AURO-Dutasteride
  • MED-Dutasteride
  • MINT-Dutasteride
  • PMS-Dutasteride
  • RIVA-Dutasteride
  • SANDOZ Dutasteride
  • TEVA-Dutasteride
  • Armonia
  • Avidart
  • Avodart
  • Avolve
  • Bengiride
  • Duagen
  • Duavo
  • Duprost
  • Dutagen
  • Dutamax
  • Dutamex
  • Dutasia
  • Dutaslow
  • Dutesmol
  • Neodart
  • Prostasil
  • Prostatex
  • Quedute
  • Terod
  • Urodart
  • Zagallo

Dutasteride Brand Names in Pakistan:

Dutasteride Capsules 0.5 mg

Avodart

Glaxosmithkline

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