Does Proscar (finasteride) cause side effects?
Proscar (finasteride) is prescribed to treat enlarged prostate (benign prostatic hyperplasia, BPH). Prostate gland enlargement is directly dependent on DHT (a hormone converted from the male hormone testosterone).
Proscar inhibits the enzyme necessary for the conversion of testosterone to DHT in the prostate. Proscar lowers blood and tissue DHT levels and helps reduce the size of the prostate gland. Although reductions in the size of the prostate gland can occur in virtually all the patients who take Proscar, only 50% will experience improvement in the symptoms of BPH.
Patients generally respond Proscar in several weeks, but it often takes 6 months for the patient to receive the full effect of the drug. Finasteride also is prescribed to treat male pattern baldness in androgenetic alopecia in males only, under the brand name Propecia.
Common side effects of Proscar include
Serious side effects of Proscar include
Drug interactions of Proscar are generally not a problem. Proscar causes abnormal development of the sexual organs of the male fetus.
Women who are pregnant or are likely to be pregnant should not handle crushed or broken Proscar tablets in order to prevent absorption through the skin. Proscar is not prescribed for women and should not be used while breastfeeding.
What are the important side effects of Proscar (finasteride)?
- Side effects are rare but can include impotence and decreased sex drive.
- Finasteride should not be used by women, children, or male partners of women trying to become pregnant.
- Finasteride should not be used until a thorough prostate examination has been done to exclude cancer, stricture, or infection in the gland. Rarely, cases of male breast cancer have been reported.
Proscar (finasteride) side effects list for healthcare professionals
Clinical Trials Experience
Proscar is generally well tolerated; adverse reactions usually have been mild and transient.
4-Year Placebo-Controlled Study (PLESS)
- In PLESS, 1524 patients treated with Proscar and 1516 patients treated with placebo were evaluated for safety over a period of 4 years.
- The most frequently reported adverse reactions were related to sexual function. 3.7% (57 patients) treated with Proscar and 2.1% (32 patients) treated with placebo discontinued therapy as a result of adverse reactions related to sexual function, which are the most frequently reported adverse reactions.
- Table 1 presents the only clinical adverse reactions considered possibly, probably or definitely drug related by the investigator, for which the incidence on Proscar was ≥1% and greater than placebo over the 4 years of the study.
- In years 2-4 of the study, there was no significant difference between treatment groups in the incidences of impotence, decreased libido and ejaculation disorder.
Table 1: Drug-Related Adverse Experiences
|Years 2, 3 and 4*|
|Decreased Volume of Ejaculate||3.7||0.8||1.5||0.5|
|N = 1524 and 1516, finasteride vs placebo, respectively|
*Combined Years 2-4
Phase III Studies And 5-Year Open Extensions
- The adverse experience profile in the 1-year, placebo-controlled, Phase III studies, the 5-year open extensions, and PLESS were similar.
Medical Therapy Of Prostatic Symptoms (MTOPS) Study
- In the MTOPS study, 3047 men with symptomatic BPH were randomized to receive Proscar 5 mg/day (n=768), doxazosin 4 or 8 mg/day (n=756), the combination of Proscar 5 mg/day and doxazosin 4 or 8 mg/day (n=786), or placebo (n=737) for 4 to 6 years.
- The incidence rates of drug-related adverse experiences reported by ≥2% of patients in any treatment group in the MTOPS Study are listed in Table 2.
- The individual adverse effects which occurred more frequently in the combination group compared to either drug alone were:
- postural hypotension,
- peripheral edema,
- decreased libido,
- abnormal ejaculation,
- impotence and
- abnormal sexual function (see Table 2).
- Of these, the incidence of abnormal ejaculation in patients receiving combination therapy was comparable to the sum of the incidences of this adverse experience reported for the two monotherapies.
- Combination therapy with finasteride and doxazosin was associated with no new clinical adverse experience.
- Four patients in MTOPS reported the adverse experience breast cancer. Three of these patients were on finasteride only and one was on combination therapy. [See Long-Term Data.]
- The MTOPS Study was not specifically designed to make statistical comparisons between groups for reported adverse experiences. In addition, direct comparisons of safety data between the MTOPS study and previous studies of the single agents may not be appropriate based upon differences in patient population, dosage or dose regimen, and other procedural and study design elements.
Table 2: Incidence ≥2% in One or More Treatment Groups Drug-Related Clinical Adverse Experiences in MTOPS
|Adverse Experience||Placebo||Doxazosin 4 mg or 8 mg*||Finasteride||Combination|
|Body as a whole|
|Metabolic and Nutritional|
|Sexual Function Abnormal||0.9||2.0||2.5||3.1|
|*Doxazosin dose was achieved by weekly titration (1 to 2 to 4 to 8 mg). The final tolerated dose (4 mg or 8 mg) was administered at end-Week 4 . Only those patients tolerating at least 4 mg were kept on doxazosin. The majority of patients received the 8-mg dose over the duration of the study.|
High-Grade Prostate Cancer
- The PCPT trial was a 7-year randomized, double-blind, placebo-controlled trial that enrolled 18,882 men ≥55 years of age with a normal digital rectal examination and a PSA ≤3.0 ng/mL.
- Men received either Proscar (finasteride 5 mg) or placebo daily. Patients were evaluated annually with PSA and digital rectal exams. Biopsies were performed for elevated PSA, an abnormal digital rectal exam, or the end of study.
- The incidence of Gleason score 8-10 prostate cancer was higher in men treated with finasteride (1.8%) than in those treated with placebo (1.1%). In a 4-year placebo-controlled clinical trial with another 5α-reductase inhibitor (dutasteride, AVODART), similar results for Gleason score 8-10 prostate cancer were observed (1% dutasteride vs 0.5% placebo).
- No clinical benefit has been demonstrated in patients with prostate cancer treated with Proscar.
- During the 4- to 6-year placebo- and comparator-controlled MTOPS study that enrolled 3047 men, there were 4 cases of breast cancer in men treated with finasteride but no cases in men not treated with finasteride.
- During the 4-year, placebo-controlled PLESS study that enrolled 3040 men, there were 2 cases of breast cancer in placebo-treated men but no cases in men treated with finasteride.
- During the 7- year placebo-controlled Prostate Cancer Prevention Trial (PCPT) that enrolled 18,882 men, there was 1 case of breast cancer in men treated with finasteride, and 1 case of breast cancer in men treated with placebo.
- The relationship between long-term use of finasteride and male breast neoplasia is currently unknown.
- There is no evidence of increased sexual adverse experiences with increased duration of treatment with Proscar.
- New reports of drug-related sexual adverse experiences decreased with duration of therapy.
The following additional adverse events have been reported in postmarketing experience with Proscar. Because these events 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:
- hypersensitivity reactions, such as pruritus, urticaria, and angioedema (including swelling of the lips, tongue, throat, and face)
- testicular pain
- sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, decreased libido and ejaculation disorders (e.g. reduced ejaculate volume). These events were reported rarely in men taking Proscar for the treatment of BPH. Most men were older and were taking concomitant medications and/or had co-morbid conditions. The independent role of Proscar in these events is unknown.
- male infertility and/or poor seminal quality were reported rarely in men taking Proscar for the treatment of BPH. Normalization or improvement of poor seminal quality has been reported after discontinuation of finasteride. The independent role of Proscar in these events is unknown.
- male breast cancer
The following additional adverse event related to sexual dysfunction that continued after discontinuation of treatment has been reported in postmarketing experience with finasteride at lower doses used to treat male pattern baldness. Because the event is reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate its frequency or establish a causal relationship to drug exposure:
- orgasm disorders
What drugs interact with Proscar (finasteride)?
Cytochrome P450-Linked Drug Metabolizing Enzyme System
- No drug interactions of clinical importance have been identified.
- Finasteride does not appear to affect the cytochrome P450-linked drug metabolizing enzyme system.
- Compounds that have been tested in man have included antipyrine, digoxin, propranolol, theophylline, and warfarin and no clinically meaningful interactions were found.
Other Concomitant Therapy
- Although specific interaction studies were not performed, Proscar was concomitantly used in clinical studies with acetaminophen, acetylsalicylic acid, α-blockers, angiotensin-converting enzyme (ACE) inhibitors, analgesics, anti-convulsants, beta-adrenergic blocking agents, diuretics, calcium channel blockers, cardiac nitrates, HMG-CoA reductase inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), benzodiazepines, H2 antagonists and quinolone anti-infectives without evidence of clinically significant adverse interactions.
Proscar (finasteride) is prescribed to treat enlarged prostate (benign prostatic hyperplasia, BPH). Prostate gland enlargement is directly dependent on DHT (a hormone converted from the male hormone testosterone). Common side effects of Proscar include impotence and decreased sex drive. Proscar causes abnormal development of the sexual organs of the male fetus. Women who are pregnant or are likely to be pregnant should not handle crushed or broken Proscar tablets in order to prevent absorption through the skin. Proscar is not prescribed for women and should not be used while breastfeeding.
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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
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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
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Prostate Cancer Facts
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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).
Prostate Infection: Causes, Symptoms, and Remedies
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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.
The Early Signs of Prostate Cancer
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Treatment & Diagnosis
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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.