Finasteride Contraindication, Pregnancy Category

Last updated: February 7, 2026Reviewed date: February 7, 2026Reading time: 6 min read

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For severe symptoms, danger signs, pregnancy, child illness, or sudden worsening, seek urgent medical care.

বাংলা রোগী নোট এখনো যোগ করা হয়নি। পোস্ট এডিটরে “RX Bangla Patient Mode” বক্স থেকে সহজ বাংলা সারাংশ যোগ করুন।

এই তথ্য শিক্ষা ও সচেতনতার জন্য। এটি ডাক্তারি পরীক্ষা, রোগ নির্ণয় বা প্রেসক্রিপশনের বিকল্প নয়।

Article Summary

Finasteride contraindication is a synthetic 4-azasteroid compound. Finasteride competitively binds to and inhibits steroid type alpha-reductase in the prostate gland, liver, and skin, thereby interfering with the enzymatic conversion of testosterone to 5-dihydrotestosterone (DHT) and reducing serum DHT levels. The reduction in serum DHT levels results in diminished stimulation of androgen receptors in the nuclei of prostate cells and, so, diminished prostate cell proliferation. Finasteride,...

Key Takeaways

This article explains Mechanism of Action of Finasteride in simple medical language.
This article explains Indications of Finasteride in simple medical language.
This article explains Contraindications of Finasteride in simple medical language.
This article explains Dosage of Finasteride in simple medical language.

Educational health guideWritten for patient understanding and clinical awareness.

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Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
New weakness, severe pain, high fever, or symptoms after a serious injury.
Any symptom that feels urgent, unusual, or unsafe for the patient.

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

Learn safely

Use this article to understand possible causes, tests, treatment options, prevention, and questions to ask your clinician.

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Start here Choose the right pathway for symptoms, reports, medicines, or urgent warning signs. Disease article roadmap Read this topic step by step: meaning, symptoms, warning signs, diagnosis, treatment, prevention, and follow-up. Treatment planner Prepare questions about treatment choices, benefits, risks, side effects, and follow-up. Family & caregiver guide Organize symptoms, reports, medicines, questions, and follow-up safely. Nutrition & diet guide Prepare food, hydration, supplement, and medicine-timing questions safely. Prevention guide Organize risk factors, protective habits, screening, and warning signs. Recovery guide Prepare a safe plan for activity, rehabilitation, warning signs, and follow-up.

Definition

Finasteride contraindication is a synthetic 4-azasteroid compound. Finasteride competitively binds to and inhibits steroid type alpha-reductase in the prostate gland, liver, and skin, thereby interfering with the enzymatic conversion of testosterone to 5-dihydrotestosterone (DHT) and reducing serum DHT levels. The reduction in serum DHT levels results in diminished stimulation of androgen receptors in the nuclei of prostate cells and, so, diminished prostate cell proliferation.

Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used mainly to treat an enlarged prostate or scalp hair loss in men.^[rx]^[rx]^[rx] It can also be used to treat excessive hair growth in women and as a part of hormone therapy for transgender women.^[rx]^[rx] It is taken by mouth.^[rx]

Mechanism of Action of Finasteride

The mechanism of action of Finasteride is based on its preferential inhibition of Type II 5a-reductase through the formation of a stable complex with the enzyme. Inhibition of Type II 5a-reductase blocks the peripheral conversion of testosterone to DHT, resulting in significant decreases in serum and tissue DHT concentrations, minimal to moderate increase in serum testosterone concentrations, and substantial increases in prostatic testosterone concentrations. As DHT appears to be the principal androgen responsible for stimulation of prostatic growth, a decrease in DHT concentrations will result in a decrease in prostatic volume (approximately 20-30% after 6-24 months of continued therapy). In men with androgenic alopecia, the mechanism of action has not been fully determined, but finasteride has shown to decrease scalp DHT concentration to the levels found in the hairy scalp, reduce serum DHT, increase hair regrowth, and slow hair loss.

Indications of Finasteride

Treatment of benign prostatic hypertrophy
For the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to Improve symptoms, reduce the risk of acute urinary retention, reduce the risk of the need for surgery including transurethral resection of the prostate. Also used for the stimulation of regrowth of hair in men with mild to moderate androgenetic alopecia (male pattern alopecia, hereditary alopecia, common male baldness).
Finasteride is a 5-alpha-reductase inhibitor used to treat symptoms of benign prostatic hypertrophy and male pattern baldness. Finasteride is associated with a low rate of transient serum aminotransferase elevations but has yet to be linked to instances of clinically apparent, acute liver injury.
Benign Prostatic Hyperplasia
Androgenetic Alopecia

Contraindications of Finasteride

Finasteride may cause birth defects in a male fetus if a pregnant woman takes finasteride or is exposed to finasteride pill fragments.^[rx]^[rx] ^[rx] Finasteride induces ambiguous genitalia in male fetuses when given to pregnant rhesus monkeys, whereas no abnormalities are observed in female fetuses. There is a single case report of accidental finasteride exposure during pregnancy, although in a female infant.^[rx]^[rx]
Malignant tumor of male breast
Liver problems
Pregnancy
A mother who is producing milk and breastfeeding
High-Grade Prostate Cancer

Allergies to

5-Alfa Reductase Inhibitor
Azasteroids
Finasteride

Dosage of Finasteride

Strengths: 1 mg; 5 mg

Benign Prostatic Hyperplasia

5 mg orally once a day

Androgenetic Alopecia

1 mg orally once a day

For the treatment of male pattern hair loss (androgenetic alopecia) in men only. (Safety and efficacy have been demonstrated in men between 18 to 41 years of age with mild to moderate hair loss of the vertex and anterior mid-scalp area)

Side Effects of Finasteride

The Most Common

breast enlargement, pain when an area is touched or pressed. সহজ বাংলা: চাপ দিলে ব্যথা।" data-rx-term="tenderness" data-rx-definition="Tenderness means pain when an area is touched or pressed. সহজ বাংলা: চাপ দিলে ব্যথা।">tenderness, lumps, or nipple discharge
continued ejaculation problems after stopping the medication
decreased interest in sexual activity continuing after stopping the medication
decreased sexual ability continuing after stopping the medication
infertility or poor quality of semen
muscle pain or weakness
signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
signs of an allergic reaction including (e.g., skin rash, itchiness, hives, swelling of the lips or tongue)

Common

Chest pain or discomfort
dilated neck veins
extreme fatigue
irregular breathing
irregular heartbeat
shortness of breath
swelling of the face, fingers, feet, or lower legs
weight gain
wheezing

Rare

Blistering, flaking, or peeling of the skin
cough
difficulty with swallowing
dizziness
fast heartbeat
hives or welts
itching skin
large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
redness of the skin
skin rash
tightness in the chest
unusual tiredness or weakness
wheezing

Drug Interactions of Finasteride

may interact with following drugs, supplements & may change the efficacy of the drug

“azole” antifungals (e.g., fluconazole, itraconazole, ketoconazole)
allopregnanolone from progesterone and hence may reduce or block the sedative, anticonvulsant, anxiolytic, and various other effects of progesterone,
boceprevir
chloramphenicol
cimetidine
ciprofloxacin
clarithromycin
conivaptan
cyclosporine
delavirdine
diltiazem
grapefruit juice
macrolide antibiotics (e.g., clarithromycin, erythromycin)
nelfinavir
nicardipine
propranolol
protease inhibitors (e.g., indinavir, ritonavir, saquinavir)
St. John’s Wort
verapamil

Pregnancy Category

FDA Pregnancy Category – X

Pregnancy

When absorbed into the system of a pregnant woman, finasteride may cause abnormalities of the genitals in a male baby. Crushed or broken finasteride tablets should not be handled by women who are or may become pregnant because finasteride may be absorbed into their system through the skin.

Lactation

Finasteride should not be used by children.

References

Finasteride Contraindication, Pregnancy Category

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

Write when the problem started and how it changed.
Bring old prescriptions, investigation reports, and current medicines.
Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

What is the most likely cause of my symptoms?
Which danger signs mean I should go to hospital quickly?
Which tests are necessary now, and which can wait?
How should I take medicines safely and what side effects should I watch for?
When should I come for follow-up?

Tests to discuss

Vital signs: temperature, pulse, blood pressure, oxygen saturation
Basic physical examination by a clinician
CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

Avoid heavy lifting, sudden bending, and prolonged bed rest.
Use comfortable posture and gentle movement as tolerated.
Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

Do not start antibiotics without a proper medical decision.
Do not use steroid tablets or injections casually for quick relief.
Do not delay emergency care because of home remedies.

Get urgent help if

Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.

Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Emergency care / cardiology / medicine doctor

Tests to discuss with doctor

ECG as early as possible when chest pain suggests heart risk
Troponin or cardiac blood tests if doctor suspects heart attack
Blood pressure, oxygen level, chest examination, and other tests as advised urgently

Questions to ask

What is the most likely cause of my symptoms?
Which warning signs mean I should go to emergency care?
Which tests are really needed now?
Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?
Is this heart-related, and do I need emergency observation?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Go to emergency care if you notice:

Severe or rapidly worsening symptoms
Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration

Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.

Step 1
Check danger signs first

If danger signs are present, seek emergency care and do not wait for online information.
Step 2
Record the symptom story

Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.
Step 3
Visit a qualified clinician

A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.
Step 4
Do only useful tests

Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.
Step 5
Follow up and return early if worse

If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips

Take a written symptom diary and all previous prescriptions/test reports.
Do not hide medicines already taken, even herbal or over-the-counter medicines.
Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

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Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

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