Megexia

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Megexia

Method of action: Endocrine Therapy

Treatment option: Anorexia, Cachexia, Cancer, Breast Cancer

Medically reviewed

Laura Arias

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 Megexia

What is Megexia?

Megexia is a prescription-only medication that contains the active compound megestrol acetate, a synthetic hormonal medicine used to influence metabolic pathways. It is classified as a progestin, meaning it is derived from and mimics the activity of the body's natural hormone, progesterone.

Property Description
Active ingredient Megestrol acetate
Form Oral tablet, Oral suspension
Pharmacological class Progestin, Synthetic Steroidal Derivative
Common use Appetite stimulation, hormonal modulation
Origin Synthetic (man-made)

Definition and Pharmacological Classification

Megexia's active ingredient, megestrol acetate, is defined as both an antineoplastic and a progestational drug, highlighting its complex dual role in therapeutic medicine. This pharmacological class, the progestins, are synthetic compounds that function as agonists of the progesterone receptor. The compound is chemically engineered as a synthetic derivative of progesterone, which grants it enhanced potency and stability when administered via the oral route.

Composition, Origin, and Available Forms

The medication is a single-ingredient product, with megestrol acetate typically provided in a micronized form to optimize its absorption in the body. Megexia is administered via the oral route, available to patients as an oral tablet and a liquid oral suspension. The liquid suspension—a key differentiating factor from many standard solid-form hormonal medicines—provides an essential therapeutic option for patients who may struggle with swallowing tablets.

General Purpose and High-Level Action

The overarching general purpose of this synthetic progestin is to facilitate systemic hormonal modulation and exert a distinct, clinically recognized appetite-stimulating effect. The active compound is associated with improvement in appetite and slight weight gain in applicable patient populations. This means the medication has a measurable, supported benefit in helping patients stabilize or increase their body weight by counteracting metabolic signals that drive severe, unintentional weight loss.

Regulatory References

  1. NCI Drug Dictionary: Megestrol Acetate
  2. MedlinePlus: Megestrol Drug Information

What side effects are possible with Megexia?

Megexia's safety profile is documented in official regulatory labeling and is organized by frequency and the body system affected, reflecting the drug's potent hormonal activity.

Adverse Reaction Scope

| Classification | Examples of Documented Effects | Affected System-Organ Class | | :--- | :--- | :--- | | Very Common (ge10%) | Weight gain, Hot flush, Constipation, Dyspnoea, Hypertension | Metabolism, Vascular, Gastrointestinal | | Common (1% to 10%) | Nausea, Diarrhea, Rash, Impotence, Asthenia, Vomiting | Gastrointestinal, Reproductive, General Disorders |

Serious Adverse Reactions and Safety Constraints

Serious adverse reactions reported in regulatory sources primarily involve the vascular and endocrine systems. The potential for thromboembolic phenomena, including pulmonary embolism and thrombophlebitis, is explicitly documented. Endocrine safety concerns include the risk of Adrenal Insufficiency and the onset or exacerbation of Diabetes Mellitus.

Specific safety statements are tied to duration of use; clinical cases of Cushing's Syndrome and adrenal insufficiency have been reported in association with chronic use of Megexia and upon drug withdrawal. Therefore, the possibility of adrenal suppression is a known consideration for patients receiving or being withdrawn from long-term therapy.

  • Population-Specific Constraints: Megexia is contraindicated in known or suspected pregnancy due to the potential for fetal harm, and women of reproductive potential are advised against becoming pregnant. Caution is also advised for older adults due to a greater frequency of decreased organ function, and for patients with a history of thromboembolic disease.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory documentation describes the potential manifestations of an overdose with Megexia, which have been reported in the post-marketing setting. When an overdosage occurs, individuals may present with a documented cluster of clinical signs. These include gastrointestinal effects such as diarrhea, nausea, and abdominal pain. Other noted manifestations are respiratory changes like shortness of breath and cough, along with systemic signs such as unsteady gait, listlessness, and chest pain.

It is officially documented that high-dose studies of Megexia, administered up to 1200 mg/day, resulted in no serious unexpected side effects, providing context for the severity profile.

Required Emergency Actions and Management

In the event of a suspected overdose, the official regulatory instruction is clear: appropriate supportive measures should be taken. This procedural instruction indicates that immediate medical attention is necessary to manage the resulting symptoms. It is explicitly stated that no specific antidote is known to counteract the effects of megestrol acetate.

Furthermore, due to the low solubility of the drug, it is officially postulated that dialysis would not be an effective means of treating an overdose. Management is therefore restricted to symptomatic support as defined by regulatory bodies.

Therapeutic Uses of Megexia

What Megexia Treats: Main Uses and Benefits

Megexia is commonly used in the management of severe, unintended loss of appetite (anorexia) and the associated state of body wasting (cachexia). This therapeutic use generally helps address symptom clusters related to systemic imbalance and significant physiological strain.

The medication is generally applied in contexts involving chronic, advanced illnesses where patients experience involuntary weight loss, such as HIV/AIDS-associated wasting syndrome and cancer-associated anorexia. Furthermore, it is a hormonal agent applied in the management of specific advanced, recurrent, or metastatic cancers, notably advanced breast cancer and endometrial cancer.

The therapeutic benefit is supportive. Its use provides support that helps ease the overall symptom burden by contributing to nutritional status and supporting general well-being during symptomatic phases. This is often seen in palliative care settings where additional symptomatic assistance is needed to help patients cope more steadily with symptom fluctuations.


Quick Fact: Management of Severe Appetite Loss The medication is commonly used when loss of appetite becomes clinically significant, assisting with efforts to stabilize body weight and maintain nutritional health during chronic illness.

Regulatory References

  1. NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

Official Population Eligibility for Megexia

The use of Megexia is strictly defined by regulatory eligibility criteria, focusing on absolute exclusions and specific restrictions.

Contraindicated Populations (Must Not Use): Megexia is absolutely prohibited for individuals with a known hypersensitivity to megestrol acetate or any component of the formulation. It is contraindicated in patients with a known or suspected pregnancy. Use for the diagnostic confirmation of pregnancy is also prohibited.

Age and Reproductive Status: The safety and effectiveness have not been established in the pediatric population, meaning use is not recommended for children. Females of reproductive potential must use effective contraception during treatment. If use is required, nursing must be discontinued. Geriatric patients require cautious dose selection due to a higher frequency of reduced organ function.

Condition-Based Restrictions: The medicine should be used with caution in patients with a history of thromboembolic disease (blood clots) or those with diabetes mellitus. Caution is also advised for patients with renal impairment, as the drug is substantially excreted by the kidneys.

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Megexia


Interaction Scope

Category Official Regulatory Documentation
Medicinal product categories with documented interactions Anticoagulants; Antidiabetic Agents; Antiretrovirals
Specific interacting medicines (if explicitly listed) Dofetilide; Indinavir; Warfarin; Antidiabetic Agents
Mechanistic basis of interactions (only if stated in label) Renal Cationic Secretion Inhibition; CYP3A4 Induction; Pharmacodynamic Antagonism
Timing-based interaction rules (if applicable) None documented.
Population-specific interaction notes (if applicable) Increased monitoring is required for patients with Diabetes Mellitus.
Interaction-related restrictions Co-administration with Dofetilide is contraindicated.

Interaction Classifications (High-Level)

Classification Type Official Regulatory Statement
Interaction severity classification (as defined in official documents) Contraindicated Combination (with Dofetilide); Clinically Significant Interaction requiring monitoring
Regulatory basis (EMA / FDA / etc.) Official prescribing information.
Interaction-context constraints (as defined in official documents) Requirement for close monitoring of INR when co-administered with Warfarin; Requirement for closer monitoring of blood glucose/antidiabetic regimen in diabetic patients.

Resulting Interaction Structure

Official Interaction Statements:

  • Co-administration with Dofetilide is contraindicated due to documented inhibition of the renal cationic secretion pathway, which results in elevated Dofetilide concentrations.
  • Megestrol acetate acts as an inducer of the CYP3A4 enzyme, which significantly decreases the plasma exposure of co-administered CYP3A4 substrate medicines, such as the antiretroviral Indinavir.
  • A pharmacodynamic antagonism is documented with antidiabetic agents, where megestrol acetate may impair glucose tolerance and require adjustments to the diabetes regimen.
  • Megestrol acetate may increase the effect of Warfarin, necessitating that the International Normalized Ratio (INR) be closely monitored.
  • No interaction is documented with food, and the oral suspension may be taken without regard to meals.

Connection to the overall interaction profile (4 sentences): The official regulatory interaction profile for Megexia is defined by specific pharmacokinetic and pharmacodynamic domains that establish mandatory constraints. The profile is structured around a contraindication due to renal transporter inhibition and specific requirements for monitoring based on CYP3A4 induction and pharmacodynamic antagonism with antidiabetic agents. Officially documented interaction statements specify the quantified exposure changes and procedural constraints. This structure provides the necessary official information for regulatory adherence regarding co-administration risks.

Mechanism of Action

Hormone Receptor Agonism and Metabolic Modulation

Megexia's action begins at the molecular level as a synthetic agonist of the Progesterone Receptor (PR). This binding triggers changes in gene transcription within cells, leading to a long-term modulation of catabolic signaling pathways. The drug also engages the Hypothalamic-Pituitary-Adrenal (HPA) axis and other steroid receptors, contributing to the transition toward a state favoring energy deposition.

Dual Pathway Appetite Signaling

The drug's effect on mass is achieved through a coordinated action on central and systemic pathways. Megexia indirectly modulates the hypothalamus in the brain, leading to the upregulation of Neuropeptide Y (NPY), a signaling molecule that increases the central perception of hunger. Concurrently, it suppresses the systemic activity of pro-inflammatory cytokines (e.g., TNF-alpha and IL-6), which are biochemical mediators associated with tissue wasting.

Resulting Physiological Effect

The combination of enhanced central orexigenic signals and reduced systemic catabolic signals modulates the body's metabolic equilibrium. This coordinated, system-level shift results in a net effect where energy intake exceeds the energy utilized for catabolic processes. This action induces the physiological conditions for body mass accumulation, specifically resulting in the deposition of adipose tissue.

Dosage and Administration Information

Official Administration Guidelines

Megexia is administered via the oral route (tablet or suspension) using a daily frequency pattern. Official dosing rules are specific to the dosage form and condition. Before initiating treatment, females of reproductive potential must obtain a negative pregnancy test and be advised to use effective contraception throughout therapy.


Administration Details

Classification Rule
Route of Administration Oral
Preparation Oral suspension must be shaken well before using.
Missed Dose Rule If a dose is missed, take it as soon as possible. If it is nearly time for the next dose, skip the missed dose and return to the regular schedule. Do not double doses.

Official Dosing Schedule (Adults)

Condition Dosage (Tablet) Dosage (Suspension 125 mg/mL)
Breast Carcinoma 160 mg/day (e.g., 40 mg four times a day) N/A
Endometrial Carcinoma 40–320 mg/day in divided doses N/A
AIDS-related Cachexia/Anorexia N/A Initial: 625 mg/day (5 mL/day or one teaspoon daily)

Procedural Steps

  1. For females of reproductive potential, obtain a negative pregnancy test prior to the first dose.
  2. If using the oral suspension, shake the container well immediately before measuring the dose.
  3. Administer the dose orally at the determined daily frequency.
  4. For carcinoma indications, a minimum of two months of continuous treatment is considered an adequate period to determine efficacy.

Connection to the overall use protocol:

The official instructions define a precise, structured protocol focused exclusively on the mechanical use of the drug, establishing the oral route and required daily dosing for specific adult conditions. The procedure also incorporates mandatory pre-administration checks (pregnancy test) and specific handling instructions for the liquid formulation (shaking), ensuring correct preparation and precise dosage delivery.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Megexia (Megestrol Acetate)

Megexia was studied for research contexts related to appetite and weight, as well as its specific hormonal application in certain cancers. The available evidence comes from formally designed clinical trials and scientific reviews that summarize those trials, providing context but not individual predictions.


Evidence for Severe Appetite Loss and Body Wasting (Anorexia/Cachexia)

Research primarily involved Randomized Controlled Trials (RCTs) to examine specific outcomes. These short-term studies typically compared Megexia to a placebo in adults with severe, unintentional weight loss, often related to conditions like advanced cancer or HIV/AIDS. Researchers focused on outcomes reflecting daily functioning or activity level, measuring changes in appetite and monitoring changes in total body weight.

Findings indicate patterns related to an increase in measured body weight and reported appetite among study participants. However, studies explored body composition and reported that the observed weight increase was observed in some studies to be associated with a disproportionate accrual of fat mass rather than lean muscle mass. Evidence related to overall Quality of Life (QoL) was mixed or varied considerably across different studies.

What Primary Clinical Trials Investigated

The specific endpoints that researchers monitored included the magnitude of weight change and how patients reported changes in appetite over defined time intervals. These studies focus on short-term changes and apply only to the populations studied.


Evidence for Hormonal/Palliative Treatment in Specific Cancers

Megexia was studied for a distinct hormonal role in treating advanced, recurrent, or metastatic breast cancer and endometrial carcinoma. Research examined its role in the palliative setting through Phase II and Phase III Clinical Trials.

Investigators monitored specific oncology outcomes such as tumor response rate and time until cancer progression. The core research for this application is derived from older, established clinical trials. Consequently, comparative evidence against newer hormonal and targeted therapies is limited in the existing scientific literature.


What is Still Uncertain About Megexia Research

Data for certain groups remain insufficient, particularly for children. The evidence quality varies across studies, leading to some inconsistency in findings. Furthermore, the durability of observed changes and data regarding long-term health outcomes, such as survival, are not fully established.

Frequently Asked Questions (FAQ)

Common questions about Megexia (FAQ)

Q: Is Megexia a treatment or a way to manage symptoms?

According to official product information, Megexia is indicated for the palliative treatment of specific advanced cancers and for the treatment of anorexia or unexplained weight loss in AIDS patients. Palliative means its use is focused on relieving symptoms and improving quality of life, rather than curative intent. This dual role means its application focuses on either symptom relief or affecting disease progression, depending on the condition being addressed.

Q: Is Megexia considered a strong medicine?

Megexia is a synthetic hormonal medicine that has a potent effect on the body's systems, including known glucocorticoid activity. Official documents contain important warnings about the possibility of thromboembolic events (blood clots) and the risk of adrenal insufficiency with chronic use. These warnings reflect the medication's potent action and the need for close monitoring during use.

Q: Does Megexia affect energy levels or cause fatigue?

Yes, regulatory documents list asthenia as a common adverse reaction reported in clinical trials. Asthenia is the clinical term for general weakness or a notable lack of energy, which a patient may describe as fatigue.

Q: How quickly can a person expect to notice the effects of Megexia?

The timeframe over which effects may be observed can vary based on the condition being addressed. For its use in carcinoma, official guidelines state that at least two months of continuous treatment is considered adequate to determine efficacy. For the appetite stimulation indication, some research timelines suggest an observation period as short as 4 weeks to look for early indications of effect.

Q: Does Megexia need to be taken long-term?

Official guidelines do not set a mandatory duration for Megexia use. Official documentation notes risks associated with chronic use, including reports of adrenal insufficiency and Cushing’s Syndrome. The official documentation emphasizes the need to assess ongoing risks when therapy is extended over a long period.

Q: What happens if I stop taking Megexia suddenly?

Stopping Megexia suddenly, especially after using it for an extended period (chronic use), carries a risk of developing adrenal insufficiency. Patients should be aware of this potential risk, and any concerning symptoms that appear during or after withdrawal are noted in regulatory information as requiring medical review.

Q: Is it true that people with liver or kidney problems cannot use Megexia?

Official product information advises caution for patients with renal impairment (kidney problems) because the drug is substantially excreted by the kidneys. Official documents do not contain specific cautions regarding the use of Megexia in patients with liver problems.

Q: What is the experience of people who have been on Megexia for over a year?

Studies focused on the use of Megexia often focus on short-term outcomes, and long-term data on health outcomes are not fully established. However, patients on chronic therapy have an officially reported risk of developing adrenal insufficiency and, in rare instances, features of Cushing's syndrome.

Q: Do I need a special type of prescription for Megexia?

Megexia is categorized as a prescription-only drug, which means it requires authorization from a licensed healthcare provider. It is not classified as a controlled substance by the DEA (Drug Enforcement Administration).

Q: Is Megexia used to treat conditions other than the main indication?

Official regulatory documents only describe the use of Megexia for the specific conditions for which it was studied and approved: palliative treatment of advanced breast or endometrial carcinoma and the treatment of anorexia/cachexia in AIDS patients.

Q: Is Megexia ever prescribed in combination with other medications?

Yes. Regulatory information includes detailed warnings regarding drug interactions with medicines such as anticoagulants, antiretrovirals, and antidiabetic agents. The existence of these warnings indicates that Megexia is often used in combination with other prescription treatments.

Q: Can taking Megexia make you feel dizzy or lightheaded?

While not a common side effect in all trials, regulatory safety reports have included nervous system adverse reactions such as dizziness and confusion. Official information notes that caution is necessary when performing tasks requiring mental alertness.

Q: Is Megexia something that builds up in your system over time?

Information from pharmacokinetics studies indicates the drug has a relatively long elimination half-life, which can range widely (typically around 34 hours). A long half-life means the active substance takes an extended period to be eliminated from the body.

Q: Do I need to avoid alcohol completely while on Megexia?

Official regulatory documents do not list a specific interaction or contraindication with alcohol. However, due to reported nervous system adverse reactions (e.g., confusion), the potential combined effects of alcohol use and Megexia's reported side effects are a consideration noted in general safety practices.

Q: Is there a generic version of Megexia available?

Yes, megestrol acetate, the active ingredient in Megexia, is available as a generic medication in various forms.

Q: Where can I find the official studies about Megexia?

The official clinical trials that supported the drug's approval are summarized in the Clinical Studies section of the FDA-approved labeling (DailyMed). These documents provide detailed information on the research outcomes.

Q: What are the official warnings about Megexia and driving or operating machinery?

Official reports document adverse reactions like dizziness and confusion. Official information notes that caution is necessary when performing tasks that require mental alertness, such as driving or operating machinery, due to these reported adverse effects.

Q: Does Megexia have a potential for abuse or dependence?

Megexia is not classified as a controlled substance by any federal agency. Official regulatory documents do not contain specific warnings regarding a potential for abuse or the development of physical dependence.

Q: What should I do if I think I'm having a serious allergic reaction to Megexia?

Official information confirms that hypersensitivity (severe allergic reaction) is a listed contraindication for use. Regulatory materials describe the importance of documenting and reviewing all adverse reactions.

Q: Can Megexia be taken with my vitamins and supplements?

Regulatory materials note the importance of reviewing all co-administered products, including prescription medicines, vitamins, and supplements. There are no documented interactions with common vitamins listed in the official regulatory documents.

Q: Are there specific times of day that Megexia is usually taken?

The official labeling provides a required daily frequency pattern but does not mandate a particular time of day for dosing. The tablet formulation, especially when used for cancer treatment, is often taken as divided doses throughout the day.

Q: Can people with pre-existing heart conditions use Megexia?

The official labeling advises caution for patients with a history of thromboembolic disease (a condition involving blood clots). Additionally, heart failure is listed as a documented, though less common, adverse reaction.

How should Megexia be stored and disposed of?

How to Store and Dispose of Megexia?

Regulatory documents mandate specific conditions to ensure the stability and safe handling of Megexia (megestrol acetate).


Storage Requirements

Condition Requirement (Official Labeling)
Temperature Store at Controlled Room Temperature, between 20 C and 25 C (68 F and 77 F).
Protection Keep from freezing and protect from excessive heat and light.
Container Keep in the original container and maintain it tightly closed.
Handling The oral suspension must be shaken well before using.

Safety and Disposal

Megexia must be stored out of the sight and reach of children in a secure location. Disposal of unused or expired product must be managed strictly in accordance with local, national, and international regulations.

Regulatory guidance prohibits discarding the medicine into household drains or sewage systems to prevent environmental contamination.

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

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