Does Avodart (dutasteride) cause side effects?
It improves symptoms of an enlarged prostate, reduces retaining of urine, and reduces the risk of the need for prostate surgery. The male hormone dihydrotestosterone (DHT) is primarily responsible for the development and enlargement of the prostate gland. Testosterone is converted into DHT by the 5-alpha reductase enzyme.
Common side effects of Avodart include
- sexual side effects such as
- breast enlargement and tenderness.
Serious side effects of Avodart include allergic reactions such as
- swelling under the skin and
- increased risk of high-grade prostate cancer.
Drug interactions of Avodart include ketoconazole, cimetidine, diltiazem, verapamil, ritonavir, and clarithromycin, which slow down the breakdown of Avodart. This may lead to increased levels of Avodart in the body, increasing side effects such as decreased libido, erectile dysfunction, and impotence.
Medications such as carbamazepine and primidone increase the breakdown of Avodart in the body. This may lead to decreased levels of Avodart in the body, lowering the beneficial effects of the medication.
Avodart is not recommended to pregnant females because it can cause birth defects in the unborn child. It is unknown if Avodart enters breast milk. Avodart is not usually used in women and is unlikely to be used during pregnancy or breastfeeding.
What are the important side effects of Avodart (dutasteride)?
Dutasteride causes many sexual side effects.
Common side effects are:
- Decreased libido
- Ejaculation disorder
- Breast enlargement and tenderness
Allergic reaction such as swelling under the skin may occur. Dutasteride also increases risk of high-grade prostate cancer. Patients must contact their healthcare professional if unusual reactions to dutasteride occur.
Avodart (dutasteride) side effects list for healthcare professionals
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trial of another drug and may not reflect the rates observed in practice.
From clinical trials with Avodart as monotherapy or in combination with tamsulosin:
- The most common adverse reactions reported in subjects receiving
- decreased libido,
- breast disorders (including breast enlargement and tenderness), and
- ejaculation disorders.
- The most common adverse reactions reported in subjects receiving combination therapy (Avodart plus tamsulosin) were
- impotence, decreased libido, breast disorders (including breast enlargement and tenderness), ejaculation disorders, and dizziness. Ejaculation disorders occurred significantly more in subjects receiving combination therapy (11%) compared with those receiving Avodart (2%) or tamsulosin (4%) as monotherapy.
- Trial withdrawal due to adverse reactions occurred in 4% of subjects receiving Avodart and 3% of subjects receiving placebo in placebo-controlled trials with Avodart.
- The most common adverse reaction leading to trial withdrawal was impotence (1%).
- In the clinical trial evaluating the combination therapy, trial withdrawal due to adverse reactions occurred in 6% of subjects receiving combination therapy (Avodart plus tamsulosin) and 4% of subjects receiving Avodart or tamsulosin as monotherapy.
- The most common adverse reaction in all treatment arms leading to trial withdrawal was erectile dysfunction (1% to 1.5%).
- Over 4,300 male subjects with BPH were randomly assigned to receive placebo or 0.5-mg daily doses of Avodart in 3 identical 2-year, placebo-controlled, double-blind, Phase 3 treatment trials, each followed by a 2-year open-label extension.
- During the double-blind treatment period, 2,167 male subjects were exposed to
- 1,772 exposed for 1 year and
- 1,510 exposed for 2 years.
- When including the open-label extensions, 1,009 male subjects were exposed to Avodart for 3 years and 812 were exposed for 4 years.
- The population was aged 47 to 94 years (mean age: 66 years) and greater than 90% were white. Table 1 summarizes clinical adverse reactions reported in at least 1% of subjects receiving Avodart and at a higher incidence than subjects receiving placebo.
Table 1: Adverse Reactions Reported in ≥1% of Subjects over a 24-Month Period and More Frequently in the Group Receiving Avodart than the Placebo Group (Randomized, Double-blind, Placebo-Controlled Trials Pooled) by Time of Onset
|Adverse Reaction||Adverse Reaction Time of Onset|
|Months 0-6||Months 7-12||Months 13-18||Months 19-24|
|Avodart (n)||(n = 2,167)||(n = 1,901)||(n = 1,725)||(n = 1,605)|
|Placebo (n)||(n = 2,158)||(n = 1,922)||(n = 1,714)||(n = 1,555)|
|Ejaculati on disordersa|
|a These sexual adverse reactions are associated with dutasteride treatment (including monotherapy and combination with tamsulosin). These adverse reactions may persist after treatment discontinuation. The role of dutasteride in this persistence is unknown.|
b Includes breast tenderness and breast enlargement.
Long-term Treatment (Up to 4 Years)
High-grade Prostate Cancer
- The REDUCE trial was a randomized, double-blind, placebo-controlled trial that enrolled 8,231 men aged 50 to 75 years with a serum PSA of 2.5 ng/mL to 10 ng/mL and a negative prostate biopsy within the previous 6 months.
- Subjects were randomized to receive placebo (n = 4,126) or 0.5-mg daily doses of Avodart (n = 4,105) for up to 4 years. The mean age was 63 years and 91% were white.
- Subjects underwent protocol-mandated scheduled prostate biopsies at 2 and 4 years of treatment or had “for-cause biopsies” at non-scheduled times if clinically indicated.
- There was a higher incidence of Gleason score 8-10 prostate cancer in men receiving Avodart (1.0%) compared with men on placebo (0.5%).
- In a 7-year placebo-controlled clinical trial with another 5 alpha-reductase inhibitor (finasteride 5 mg, PROSCAR), similar results for Gleason score 8-10 prostate cancer were observed (finasteride 1.8% versus placebo 1.1%).
- No clinical benefit has been demonstrated in patients with prostate cancer treated with Avodart.
Reproductive And Breast Disorders
- In the 3 pivotal placebo-controlled BPH trials with Avodart, each 4 years in duration, there was no evidence of increased sexual adverse reactions (impotence, decreased libido, and ejaculation disorder) or breast disorders with increased duration of treatment.
- Among these 3 trials, there was 1 case of breast cancer in the dutasteride group and 1 case in the placebo group.
- No cases of breast cancer were reported in any treatment group in the 4-year CombAT trial or the 4-year REDUCE trial.
- The relationship between long-term use of dutasteride and male breast neoplasia is currently unknown.
Combination With Alpha-blocker Therapy (CombAT)
- Over 4,800 male subjects with BPH were randomly assigned to receive 0.5-mg Avodart, 0.4-mg tamsulosin, or combination therapy (0.5-mg Avodart plus 0.4-mg tamsulosin) administered once daily in a 4-year double-blind trial.
- Overall, 1,623 subjects received monotherapy with Avodart;
- 1,611 subjects received monotherapy with tamsulosin; and
- 1,610 subjects received combination therapy.
- The population was aged 49 to 88 years (mean age: 66 years) and 88% were white.
- Table 2 summarizes adverse reactions reported in at least 1% of subjects in the combination group and at a higher incidence than subjects receiving monotherapy with Avodart or tamsulosin.
Table 2: Adverse Reactions Reported over a 48-Month Period in ≥1% of Subjects and More Frequently in the Coadministration Therapy Group than the Groups Receiving Monotherapy with Avodart or Tamsulosin (CombAT) by Time of Onset
|Adverse Reaction||Adverse Reaction Time of Onset|
|Year 1||Year 2||Year 3||Year 4|
|Months 0-6||Months 7-12|
|Combinationa||(n = 1,610)||(n = 1,527)||(n = 1,428)||(n = 1,283)||(n = 1,200)|
|Avodart||(n = 1,623)||(n = 1,548)||(n = 1,464)||(n = 1,325)||(n = 1,200)|
|Tamsulosin||(n = 1,611)||(n = 1,545)||(n = 1,468)||(n = 1,281)||(n = 1,112)|
|a Combination =
Avodart 0.5 mg once daily plus tamsulosin 0.4 mg once daily.|
b Includes anorgasmia, retrograde ejaculation, semen volume decreased, orgasmic sensation decreased, orgasm abnormal, ejaculation delayed, ejaculation disorder, ejaculation failure, and premature ejaculation.
c These sexual adverse reactions are associated with dutasteride treatment (including monotherapy and combination with tamsulosin). These adverse reactions may persist after treatment discontinuation. The role of dutasteride in this persistence is unknown.
d Includes erectile dysfunction and disturbance in sexual arousal.
e Includes libido decreased, libido disorder, loss of libido, sexual dysfunction, and male sexual dysfunction.
f Includes breast enlargement, gynecomastia, breast swelling, breast pain, breast tenderness, nipple pain, and nipple swelling.
- In CombAT, after 4 years of treatment, the incidence of the composite term cardiac failure in the combination therapy group (12/1,610; 0.7%) was higher than in either monotherapy group: Avodart, 2/1,623 (0.1%) and tamsulosin, 9/1,611 (0.6%).
- Composite cardiac failure was also examined in a separate 4-year placebo-controlled trial evaluating Avodart in men at risk for development of prostate cancer.
- The incidence of cardiac failure in subjects taking Avodart was 0.6% (26/4,105) compared with 0.4% (15/4,126) in subjects on placebo.
- A majority of subjects with cardiac failure in both trials had comorbidities associated with an increased risk of cardiac failure.
- Therefore, the clinical significance of the numerical imbalances in cardiac failure is unknown.
- No causal relationship between Avodart alone or in combination with tamsulosin and cardiac failure has been established.
- No imbalance was observed in the incidence of overall cardiovascular adverse events in either trial.
The following adverse reactions have been identified during post-approval use of Avodart. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
These reactions have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to Avodart.
Immune System Disorders
- Hypersensitivity reactions, including
- Depressed mood.
Reproductive System And Breast Disorders
What drugs interact with Avodart (dutasteride)?
Cytochrome P450 3A Inhibitors
- Dutasteride is extensively metabolized in humans by the cytochrome P450 (CYP)3A4 and CYP3A5 isoenzymes.
- The effect of potent CYP3A4 inhibitors on dutasteride has not been studied. Because of the potential for drug-drug interactions, use caution when prescribing Avodart to patients taking potent, chronic CYP3A4 enzyme inhibitors (e.g., ritonavir).
- The administration of Avodart in combination with tamsulosin or terazosin has no effect on the steady-state pharmacokinetics of either alpha-adrenergic antagonist. The effect of administration of tamsulosin or terazosin on dutasteride pharmacokinetic parameters has not been evaluated.
Calcium Channel Antagonists
- Coadministration of verapamil or diltiazem decreases dutasteride clearance and leads to increased exposure to dutasteride. The change in dutasteride exposure is not considered to be clinically significant. No dose adjustment is recommended.
- Administration of a single 5-mg dose of Avodart followed 1 hour later by 12 g of cholestyramine does not affect the relative bioavailability of dutasteride.
- Avodart does not alter the steady-state pharmacokinetics of digoxin when administered concomitantly at a dose of 0.5 mg/day for 3 weeks.
- Concomitant administration of Avodart 0.5 mg/day for 3 weeks with warfarin does not alter the steady-state pharmacokinetics of the S-or R-warfarin isomers or alter the effect of warfarin on prothrombin time.
Avodart (dutasteride) is a 5-alpha reductase inhibitor used to treat benign prostatic hyperplasia (BPH, or enlarged prostate). Common side effects of Avodart include sexual side effects such as impotence, decreased sex drive, ejaculation disorder, and breast enlargement and tenderness. Avodart is not recommended to pregnant females because it can cause birth defects in the unborn child. It is unknown if Avodart enters breast milk. Avodart is not usually used in women and is unlikely to be used during pregnancy or breastfeeding.
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Related Disease Conditions
Prostate Cancer: Erectile Dysfunction
Second Source article from The Cleveland Clinic
Prostate Cancer Staging and Survival Rates
The prognosis for prostate cancer, as with any cancer, depends on how advanced the cancer has become, according to established stage designations. The patient's PSA score at diagnosis, as well as their Gleason score (the grading system used to determine the aggressiveness of prostate cancer) determines the prognosis and final stage designation. Prostate cancer has a high survival rate in general, but your chances depend on the stage of the cancer.
Prostatitis (Inflammation of the Prostate Gland)
Prostatitis is an inflammation of the prostate gland. Signs and symptoms of prostatitis include painful or difficulty urinating; fever; chills; body aches; blood in the urine; pain in the rectum, groin, abdomen, or low back; and painful ejaculation or sexual dysfunction. Causes of prostatitis include STDs, bacteria from urinary tract infections, or E. coli. Treatment for prostatitis depends on if it is a bacterial infection or chronic inflammation of the prostate gland.
What Are the First Signs of Prostate Problems?
The first signs and symptoms of prostate disorder usually include problems with urination. Please consult your doctor if you experience any of the signs and symptoms to avoid the worsening of the prostate problems.
Prostatitis vs. BPH (Enlarged Prostate): What Is the Difference?
Prostatitis and BPH (benign prostatic hyperplasia, enlarged prostate gland) are both conditions of the prostate gland. Check out the center below for more medical references on prostate gland conditions, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.
Enlarged Prostate (BPH, Benign Prostatic Hyperplasia)
Benign prostatic hyperplasia (BPH or enlarged prostate) is very common in men over 50 years of age. Half of all men over the age of 50 develop symptoms of BPH, but few need medical treatment. This noncancerous enlargement of the prostate can impede urine flow, slow the flow of urine, create the urge to urinate frequently and cause other symptoms like complete blockage of urine and urinary tract infections. More serious symptoms are urinary tract infections (UTIs) and complete blockage of the urethra, which may be a medical emergency. BPH is not cancer. Not all men with the condition need treatment, and usually is closely monitored if no symptoms are present. Treatment measures usually are reserved for men with significant symptoms, and can include medications, surgery, microwave therapy, and laser procedures. Men can prevent prostate problems by having regular medical checkups that include a prostate exam.
What Are the 5 Warning Signs of Prostate Cancer?
Prostate cancer rarely produces symptoms in the early stage; however, few signs can help in detecting prostate cancer.
Does an Enlarged Prostate Affect a Man Sexually?
An enlarged prostate can cause sexual problems in men. Sexual problems, such as erectile dysfunction or ejaculation problems, may occur in men with noncancerous enlargement of the prostate (benign prostatic hyperplasia or BPH).
Prostate cancer is the most common cancer in men after skin cancer. Risk factors include age, family history, ethnicity, and diet. Prostate cancer is diagnosed by a digital rectal exam, prostate-specific antigen (PSA) test, and prostate biopsy. Symptoms may include frequent need to urinate, incontinence, pain, blood in the urine, fatigue, and more. Prognosis and treatment depend on cancer staging. Watchful waiting, surgery, radiation, cryotherapy, and other management strategies are available. Research and clinical trials strive to find new and better treatments for prostate cancer.
Prostate Cancer Treatment: Focal Therapy and Other Experimental Treatments
Several new and experimental treatments for prostate cancer are under study, including treatments that use ultrasound, lasers, tissue-freezing gas, and new ways of administering radiation. These new methods are types of focal therapy, that is, treatment focused on the cancer cells in the prostate, rather than systemic therapy that administers medications or other treatments to the whole body with the aim of treating the prostate.
Can Prostate Cancer Be Completely Cured?
Prostate cancer is the second most common cancer in men. Due to routine screening of prostate-specific antigen (PSA) levels in the United States, nearly 90% of prostate cancers get detected in early stages. When found early, there are several treatment options available and prostate cancer has a high chance of getting cured.
Prostate Cancer Early Signs and Symptoms
Difficulty with urination – frequency, weak stream, trouble getting started, etc. – is usually the first sign of prostate cancer. But these and other early symptoms of prostatic cancer can also come from benign prostate conditions, so diagnostic testing is important, including PSA tests and digital rectal exam.
Prostate Cancer Facts
Prostate cancer is a leading cause of cancer and cancer death in males; in some men, identifying it early may prevent or delay metastasis and death from prostate cancer. The prostate is a walnut-shaped gland that is a part of the male reproductive system that wraps around the male urethra at it exits the bladder. Prostate cancer is common in men over 50 years of age, with the risk of developing prostate cancer increases with aging.
How Is Prostate Cancer Diagnosed?
Prostate cancer is largely a disease of men over 40, so it’s around this age doctors recommend the first prostate screening. The first exam is a blood test to determine if there are abnormal prostate specific antigen (PSA) levels in your blood – PSA is produced by the prostate. If the PSA is high, your doctor will perform a digital rectal exam, during which the doctor feels your prostate from inside your rectum with a gloved finger. Other diagnostic tests include an endoscopic biopsy of tumor tissue for analysis in a lab.
Early-Stage Prostate Cancer Treatment
If prostate cancer is detected early and appears to be slow-growing, invasive procedures, chemotherapy, radiation and other approaches can sometimes do more harm than good. Many prostate cancer treatments come with side effects, like incontinence or impotence, so it’s in the patient’s interest to put off invasive treatments as long as is medically safe. Active surveillance is where doctors "watch and wait" for changes that could prompt medical intervention.
Prostate Cancer Treatment: Chemotherapy, Bone-Targeted and Immune Therapy
Doctors may introduce chemotherapy and immune therapy if other measures fail to cure a case of prostate cancer. However, unlike with other forms of cancer, chemotherapy isn’t the first choice for early prostate cancer. Immune therapy uses the body's own immune system to attack the prostate tumor, while bone-targeted therapy aims to preserve bone and prevent metastasis.
Prostate Cancer Treatment: Hormonal Therapy
Prostate cancer is highly sensitive to, and dependent on, the level of the male hormone testosterone, which drives the growth of prostate cancer cells. Testosterone belongs to a family of hormones called androgens, and today front-line hormonal therapy for advanced and metastatic prostate cancer is called androgen deprivation therapy (ADT).
Prostate Cancer: Radical Prostatectomy Surgery
Radical prostatectomy, or surgical removal of the entire prostate gland, isn’t typically the first choice in prostate cancer treatment. Sometimes a radical approach is necessary to keep the cancer from metastasizing, however. Some cases are too severe or diagnosed too late for drugs or radiation to have much effect. In these cases, treatment teams may opt for a radical prostatectomy, despite potential side effects like impotence and incontinence.
Where Is the Prostate?
The prostate gland, commonly known as the prostate, is one of the male reproductive organs located just below the bladder, above the penis, and in front of the rectum. It is connected to the penis by a tube (urethra) that empties urine from the bladder. The size and shape of the prostate are similar to a walnut.
Prostate Cancer: Radiation, Brachytherapy and Radiopharmaceuticals
Radiation treatment for prostate cancer is a powerful tool at doctors’ disposal. Using radiation vs. surgery or other invasive treatments to kill cancer cells may still cause side effects, but ideally they are less severe. Radiation therapy can be performed via external beam therapy (EBRT) or the placement of radioactive seeds into the prostate (prostate brachytherapy) or using radioactive drugs (radiopharmaceuticals).
When Should You Screen for Prostate Cancer?
Screening for prostate cancer helps detecta tumor early, enabling timely treatment and prevention of any complications. According to the American Cancer Society (ACS), the decision to get screened should be made by men in consultation with their doctor. The doctor needs to counsel the men about the uncertainties involved in the screening process, the risks and potential benefits of getting screened for prostate cancer.
Prostate Infection: Causes, Symptoms, and Remedies
If the prostate gland becomes swollen and tender, it is called prostatitis or prostate infection. The prostate gland is a walnut-shaped organ that lies just below a man's urinary bladder.
The Early Signs of Prostate Cancer
Prostate cancer in its early stages usually causes no signs and symptoms. Screening can help detect the cancer early.
Treatment & Diagnosis
- Enlarged Prostate BPH FAQs
- Prostate Cancer FAQs
- Prostate Cancer - New Criteria
- Prostate Cancer Risk May Be Lowered By Vitamin E
- Is Prostate Cancer Genetic?
- What Is the Prostate Cancer TNM Stage?
- What Does Prostate Cancer Do to You?
- How Do You Develop Prostate Cancer?
- What Are the Early Signs of Prostate Cancer?
Medications & Supplements
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Professional side effects and drug interactions sections courtesy of the U.S. Food and Drug Administration.