Asterid

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Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Asterid

Quick Facts

Property Description
Active ingredient Finasteride
Form Oral tablet (systemic administration)
Pharmacological class 5α-Reductase Inhibitor (Type II Selective)
Common use Managing conditions influenced by DHT
Origin Synthetic 4-azasteroid compound

Asterid: Identity, Type, and Composition

Asterid is the commercial name for the active ingredient Finasteride, a synthetic 4-azasteroid compound. This medication is supplied as a single-ingredient oral tablet intended for systemic administration and is available strictly by prescription. Finasteride is classified as a 5α-Reductase Inhibitor, a class of drugs that specifically modifies hormone metabolism. This compound is clinically recognized for its ability to regulate processes driven by specific androgens. As a solid oral dosage form, the product is composed of Finasteride combined with pharmaceutical excipients necessary for tablet structure.

Finasteride's Pharmacological Class and Unique Mechanism

Finasteride belongs to the therapeutic class of antiandrogens, distinguished by its selective action as a competitive inhibitor of the Type II 5α-reductase enzyme. The mechanism centers on blocking the conversion of the hormone Testosterone into the significantly more potent androgen, Dihydrotestosterone (DHT). This inhibition is preferential toward the Type II isozyme, which is the primary driver of DHT production in key target tissues, thus ensuring a focused biological effect.

General Purpose: Reducing DHT-Driven Biological Effects

The overarching purpose of using Asterid is to consistently lower the body’s overall concentration of Dihydrotestosterone (DHT) in target tissues by blocking its production pathway. This action addresses biological conditions where elevated or localized DHT levels are a causative factor, such as in the progressive growth of certain tissues or the gradual miniaturization of hair follicles. Therapeutic use produces a pronounced effect in reducing both plasma and tissue levels of DHT, establishing a foundational therapeutic approach to managing these hormone-related effects. This reduction in DHT activity allows the medication to exert its controlling influence on these hormone-dependent processes, making it a typical option for managing androgen-dependent issues in adult males.

Regulatory References

  1. NIH: 5α-Reductase Inhibitors (StatPearls)
  2. Finasteride - NCBI Bookshelf (StatPearls)

What side effects are possible with Asterid?

Possible side effects and safety information

The safety profile of Asterid (Finasteride) is defined by officially documented adverse reactions primarily affecting the reproductive and endocrine systems, alongside specific considerations for patient monitoring and population-based constraints. This information is derived from government regulatory documents, such as the FDA Prescribing Information and the European Summary of Product Characteristics (SmPC).

Adverse Reaction Scope and Classification

Adverse reactions are grouped by frequency and System-Organ Class (SOC). Reactions classified as Common (potentially affecting up to 1 in 10 users in clinical trials) include decreased libido, erectile dysfunction, and ejaculation disorder (including decreased volume of ejaculate). Uncommon reactions may include rash and gynecomastia (breast enlargement and tenderness).

Reactions reported during post-marketing surveillance, classified as Frequency Not Known, include depression, suicidal ideation, testicular pain, and the persistence of sexual dysfunction after treatment cessation. Reports of male breast cancer are also categorized within this post-marketing surveillance group.

Serious Safety Constraints and Population Notes

Regulatory warnings note a reduction in serum Prostate-Specific Antigen (PSA) levels by approximately 50%, which must be considered during medical monitoring for prostate cancer screening. Furthermore, an increased risk of high-grade prostate cancer has been associated with the 5 mg dose in men aged 55 and over.

Asterid is contraindicated for use in women, particularly those who are or may become pregnant, due to the potential risk of external genitalia abnormalities in a male fetus. The medication is not indicated for use in pediatric patients. In terms of timing, the incidence of sexual adverse reactions is typically highest during the first year of treatment.

Overdose and Emergency Response

Overdose and When to Seek Help

Official Regulatory Overdose Profile

Official regulatory information for the active ingredient in Asterid (Finasteride) is defined by its wide margin of safety and a lack of specific manifestations documented following high-dose exposure in clinical trials. All information below is derived from official government-authorized drug labeling and public health guidance.


Feature Official Regulatory Statement
Documented Overdose Presentation Clinical studies involving single oral doses up to 400 mg and multiple doses up to 80 mg/day for three months did not result in documented adverse reactions.
Specific Treatment/Antidote No specific treatment is recommended for an overdose at this time, pending further clinical experience.
Population-Specific Notes No specific differences in overdose management or severity are detailed for pediatric, geriatric, or organ-impaired populations in the Overdosage section.

Mandated Emergency Actions

Despite the drug's high safety margin, contacting health authorities is mandatory in all suspected overdose situations.

  • Poison Control Contact: Contact the local Poison Control Helpline for specific advice if an overdose is suspected.
  • Immediate Medical Help Required: Emergency services (e.g., 911) must be contacted immediately if the individual exhibits severe, life-threatening symptoms, such as having a seizure, trouble breathing, collapse, or being unable to be awakened.

Connection to the Overall Overdose Profile:

Regulatory findings establish that Finasteride does not have a documented, specific overdose syndrome, with high doses tested confirming the absence of adverse events. Because no specific pharmacological treatment is known or recommended, management would be supportive. The primary mandatory action is to seek immediate emergency medical attention for any severe, non-specific life-threatening signs, such as collapse or respiratory distress.

Therapeutic Uses of Asterid

What Asterid Treats: Main Uses and Benefits

Asterid is commonly used across two primary therapeutic domains relevant to conditions presenting with systemic or localized discomfort in adult men.

The medication is applied in clinical settings that involve symptomatic discomfort related to the non-cancerous enlargement of the prostate gland (Benign Prostatic Hyperplasia, or BPH) and is relevant in the long-term management of Androgenetic Alopecia (male pattern hair loss). This application helps address clusters of symptoms, including difficulty with urinary flow and the progressive thinning of hair on the scalp.

This supportive symptom management is appropriate in situations where the symptom burden begins to interfere with functional stability, assisting with maintaining functional stability by easing the overall symptom burden.

Quick Fact: Relief for Symptom Domains

Therapeutic Domain Primary Symptom/Context Benefit Received
Urological Health Weak stream, nocturia (LUTS) Improved day-to-day comfort
Dermatological Health Progressive scalp thinning Maintaining or preserving hair coverage

In addition to easing current symptoms, this therapeutic approach is relevant when supportive symptom management is appropriate, as it contributes to easing the overall symptom load and may assist with maintaining functional stability during symptomatic periods.

Regulatory References

  1. NIH MedlinePlus overview on Finasteride

Eligibility and Restrictions for Use

Official Eligibility Profile

The eligibility profile for Asterid (Finasteride) is strictly defined by regulatory authorities and centers on gender, reproductive status, and age.

Category Official Regulatory Status
Populations for whom use is allowed Adult Men (18 years and older).
Populations for whom use is contraindicated Pregnant females or females who may potentially be pregnant.
Age-related eligibility rules Pediatric Patients (under 18 years): Use is not indicated; safety and efficacy are not established.
Eligibility-related restrictions Known Hypersensitivity to finasteride or any component of the medication.

Conditional Use and Restrictions

Finasteride is contraindicated in women who are or may become pregnant due to the potential hazard to a male fetus. The official label specifies that women who are pregnant must not handle crushed or broken tablets due to the risk of absorption. The medication is not indicated for use in women for its approved male indications.

Regarding organ function, patients with known liver function abnormalities (hepatic impairment) should use the medicine with caution, as the drug is metabolized extensively in the liver. Conversely, the official label states that no dosage adjustment is necessary for geriatric patients or for patients with renal impairment.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory information for Asterid (Finasteride) indicates a lack of clinically significant interactions with a wide range of commonly tested medicinal products. The official label establishes a low risk of problematic co-administration, with no mandatory restrictions or specific timing requirements for nearly all other substances.

Classification Official Regulatory Statement
Drug–Drug Interaction Severity No clinically meaningful interactions identified with tested compounds, including digoxin, propranolol, theophylline, warfarin, and glyburide (glibenclamide).
Contraindicated Combinations None documented. The official label does not list any medicinal products that are strictly prohibited for co-administration.
Food/Alcohol Interactions None documented. Official prescribing information does not list any clinically significant interactions with food or alcohol.

Asterid is metabolized by the Cytochrome P450 3A4 (CYP3A4) enzyme, which forms the basis for potential pharmacokinetic interaction. Co-administration with known CYP3A4 inhibitors or CYP3A4 inducers could theoretically alter the plasma concentration of Finasteride, though no clinically significant effect on the metabolism of other CYP450-linked drugs has been found. The regulatory documents also include a population-specific caution for patients with decreased hepatic function (liver disease), noting that Finasteride is extensively metabolized in the liver, and clearance has not been studied in this group. This may result in increased plasma exposure in patients with liver function abnormalities.

Mechanism of Action

Selective Blockade of the 5α-Reductase Enzyme

Finasteride acts as a competitive inhibitor that is highly selective for the Type II 5α-Reductase enzyme. This primary target is an enzyme that catalyzes the conversion of Testosterone into the significantly more potent androgen, Dihydrotestosterone (DHT). By blocking this specific metabolic step, the mechanism effectively interrupts the key synthesis pathway, initiating a cascade that leads to the molecule's overall physiological effect.


Modulation of Androgen-Dependent Signaling

The central physiological outcome of this inhibition is a notable reduction in the local and systemic concentration of DHT. This depletion limits the ability of the potent androgen to activate nuclear receptors and deliver trophic (growth-stimulating) signals to sensitive cell populations. This action modulates androgen-dependent cellular processes, resulting in a change in the tissue's hormonal signaling dynamics that shapes the molecule's physiological effect profile.


Mechanistic Constraint of Isozyme Specificity

The drug's mechanism is constrained by its selectivity: it has significantly lower affinity for the Type I 5α-Reductase isozyme, which remains active in other tissues. This isozyme sustains a residual synthesis of DHT, meaning the mechanism results in a high degree of, but not absolute, suppression of DHT levels. This boundary is intrinsic to the drug's specific mode of action.

Dosage and Administration Information

How to Use Asterid: Official Administration Guidelines

Asterid (finasteride) is prescribed as an oral tablet for systemic administration. The specific dosage strength required depends entirely on the condition being managed, but the frequency is standardized: it is to be taken once daily at approximately the same time each day for consistent drug exposure.


Standard Dosing Regimens

The approved daily dosing is determined by the specific use pattern:

Indication Official Daily Dose Administration Rule
Benign Prostatic Hyperplasia (BPH) 5 mg once daily Take continuously for at least six months before assessment.
Androgenetic Alopecia (Hair Loss) 1 mg once daily Requires continuous daily use for three months or more to observe benefit.

Administration and Handling Conditions

To ensure proper use, the tablet may be taken with or without food. The tablet must be swallowed whole and should not be crushed, broken, or chewed. This instruction also applies as a special handling constraint: individuals who are pregnant or may become pregnant must not handle crushed or broken tablets, due to the possibility of finasteride absorption.

Use Over Time and Population Rules

Finasteride is a medicine intended for long-term, continuous daily use. If a dose is missed, the standard procedure is to not take an extra dose to compensate, but simply take the next dose at the regularly scheduled time. No dosage adjustments are typically required for older adults or for patients with renal impairment.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Asterid

The research available for Asterid (Finasteride) is summarized from official clinical trials and scientific reviews. This research examines the medication in the context of conditions for which it was studied, namely Benign Prostatic Hyperplasia (BPH) and Androgenetic Alopecia (male pattern hair loss). The evidence describes group patterns observed in these studies but does not determine whether an individual will respond similarly.


Evidence for Use in Symptomatic Benign Prostatic Hyperplasia (BPH)

The evaluation for symptomatic BPH focuses on non-cancerous prostate enlargement. Research has primarily used large-scale, multi-year Randomized Controlled Trials (RCTs) against control groups. Studies explored functional measures, such as changes in the Maximum Urinary Flow Rate, and physical changes, like the change in prostate volume measured over time.

Long-term follow-up was observed in adult men for several years, and studies report how symptoms evolved in the observed populations when examining key clinical events. These events included occurrences of acute urinary retention or surgical intervention related to BPH. Research provides insight into short-term changes over extended periods when data show patterns related to these events.


Evidence for Use in Androgenetic Alopecia (Male Pattern Hair Loss)

Studies for male pattern hair loss were evaluated in adult men with conditions marked by functional limitations (hair thinning). The primary structure involves Randomized Controlled Trials (RCTs) lasting one to two years, followed by Long-term Open-label Extension Studies that have observed participants for up to a decade.

Studies explored several outcomes reflecting daily functioning related to hair appearance, including Objective Hair Counts within a defined scalp area and Subjective Assessments. Trials described that the measured changes generally began to revert several months after the study administration stopped. Open-label follow-up studies described the persistence of the initial measured changes in hair counts over the longer observation period.


Key Limitations and Unstudied Areas of Research

Despite the available evidence from large RCTs, certainty remains low for some specific areas. Long-term effects are not fully established beyond the observation periods of the original major trials, leaving gaps regarding outcomes after ten years. Comparative evidence is limited for some outcomes when examining Asterid against all other possible treatment classes.

Frequently Asked Questions (FAQ)

Common questions about Asterid (FAQ)


Q: Does Asterid cause fatigue or make you sleepy?

Official regulatory documents describe 'somnolence' (a term for unusual drowsiness or sleepiness) as a less common side effect reported in clinical data. Changes in alertness are generally reviewed during regular medical consultations.


Q: Are there different strengths or formulations of Asterid?

Official product information states that Asterid (finasteride) is available as an oral tablet in two different strengths. These strengths—1 mg and 5 mg—are specifically approved for the different conditions the drug is used to manage.


Q: How long does the effect of a single dose of Asterid typically last?

The regulatory pharmacokinetic data indicates the drug has a short half-life, meaning the amount of drug in the body is generally cleared within a couple of days. However, the action of the drug is to suppress Dihydrotestosterone (DHT) production, and this hormonal effect can last longer than the presence of the single dose itself. For this reason, official guidelines state the medication is intended for continuous daily use.


Q: Does Asterid have a 'black box warning' in the official documents?

Asterid does not carry the specific U.S. FDA Boxed Warning. However, official labeling does include important warnings and precautions. These highlight the risk of high-grade prostate cancer associated with the 5 mg dose and note the potential for certain sexual side effects to persist after stopping the medicine.


Q: Is Asterid known to cause weight gain or weight loss?

In official regulatory documents, 'unusual weight gain or loss' and 'rapid weight gain' are listed among the less common side effects. These reports generally come from clinical trials or post-marketing surveillance.


Q: Why do some people experience initial nausea when starting Asterid?

Official product information lists 'nausea' and 'stomach pain' as gastrointestinal side effects that have been reported during clinical studies or after the drug was made available to the public. These are noted effects that have been reported during clinical observation for this medication.


Q: Are there certain supplements that might interact with Asterid?

Official regulatory documents do not list specific dietary supplements that are known to interact with Asterid. The drug is metabolized in the liver by the CYP3A4 enzyme, meaning that any substance that significantly affects this enzyme could theoretically alter the amount of finasteride in the body.


Q: Is Asterid a controlled substance or scheduled drug?

According to the official drug classification by regulatory bodies like the U.S. Drug Enforcement Administration (DEA), Asterid is not listed as a controlled substance. It is only classified as a prescription-only medicine.


Q: Is Asterid available as a generic version?

Yes, the U.S. Food and Drug Administration (FDA) has approved multiple generic versions of finasteride tablets. Generic versions are available that contain the same active ingredient.


Q: What does 'contraindicated' mean regarding who cannot use Asterid?

The term 'contraindication' means that the drug should absolutely not be used because the risk of harm outweighs any potential benefit. For Asterid, official labeling strictly contraindicates its use in females who are or may become pregnant due to the risk of external genitalia abnormalities in a male fetus.


Q: Is there a patient brochure or guide provided with Asterid?

Yes, the dispensing of Asterid typically includes a Patient Information Leaflet or Medication Guide. Regulatory authorities ensure this patient information is made available at the time of dispensing.


Q: Can Asterid cause problems with sleep?

Official regulatory documents list 'somnolence' (unusual drowsiness) as a less common side effect. This effect is noted in regulatory documents, which patients may wish to review with their provider.


Q: How does the official literature describe the potential for dependence or withdrawal with Asterid?

Official documents do not classify finasteride as a dependence-forming drug. However, post-marketing reports have noted that some sexual adverse effects have been observed to persist after patients stop taking the medicine.


Q: Does Asterid interact with common cold or allergy medicines?

The official label highlights a lack of clinically significant interactions with tested medicinal products. Therefore, no specific warnings regarding common cold or allergy medicines are typically noted in the regulatory documents.


Q: Is it described as a 'cure' or a 'management' drug?

Official documents describe the use of finasteride as the 'treatment' and 'management' of conditions like BPH and male pattern hair loss. For hair loss, the positive effects are described in research as reverting several months after study administration stopped.


Q: Can a person stop taking Asterid suddenly if they feel better?

Asterid is prescribed for long-term, continuous daily use to maintain its therapeutic effect. Stopping the drug is expected to lead to a gradual increase in Dihydrotestosterone (DHT) levels, consistent with the mechanism of action.


Q: Is Asterid ever used in combination with other treatments for the same condition?

Yes, official prescribing information indicates that the 5 mg strength of finasteride is approved for use in combination with an alpha-blocker (doxazosin) to reduce the risk of symptomatic progression of Benign Prostatic Hyperplasia (BPH).

How should Asterid be stored and disposed of?

Official Storage and Disposal Requirements

Storage of this medication (doxylamine succinate and pyridoxine hydrochloride) must strictly adhere to the following regulatory guidelines to maintain its stability and safety profile.

Storage Requirement Official Instructions
Temperature and Environment Store at controlled room temperature, 20 C to 25 C (68 F to 77 F). Protect from freezing, excess heat, moisture, and direct light. Do not store in the bathroom.
Container and Handling Keep the medication in the original, tightly closed container, ensuring the safety cap is secured. Do not crush, chew, or split the tablets; they must be swallowed whole.
Child Safety Store the product in a safe, locked location that is out of the sight and reach of children.
Disposal Method The preferred disposal method for unused or expired medicine is a drug take-back program. If unavailable, mix the medicine with an undesirable substance (such as dirt or used coffee grounds) and place the mixture in a sealed bag or container before discarding it in the household trash. Do not flush this medication.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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