Mezoxia160 mg

FDA-Approved Indications

• Anorexia, cachexia, or unexplained significant weight loss in patients with acquired immunodeficiency syndrome (AIDS) - Mezoxia oral suspension is approved for the management of significant involuntary weight loss associated with HIV/AIDS.
• Palliative treatment of advanced breast cancer - Mezoxia tablets are approved for palliative management of advanced, recurrent, or metastatic breast carcinoma in women whose disease has progressed following surgery and/or radiotherapy.
• Palliative treatment of advanced endometrial carcinoma - Mezoxia tablets are approved for palliative management of advanced or recurrent endometrial carcinoma, generally in patients not considered candidates for surgery or radiotherapy.

Guideline-Supported / Commonly Used Off-Label Uses

• Cancer-associated anorexia-cachexia syndrome (non-AIDS malignancies) - Mezoxia is widely used off-label, and supported by some palliative-care and oncology guidelines, as an appetite stimulant to improve weight and quality of life in patients with cancer-related cachexia.
• Anorexia/weight loss in other chronic debilitating conditions - used off-label under close medical supervision when standard measures have failed; the potential benefit of Mezoxia must be individually weighed against thromboembolic and other risks.

Mezoxia is not indicated for the prevention of pregnancy and should never be used as a contraceptive.

Megestrol Acetate is the active ingredient in each tablet and in each dose of the oral suspension. Megestrol Acetate is a synthetic derivative of the naturally occurring hormone progesterone. In Bangladesh, Megestrol Acetate is commonly available as tablets (40 mg and 160 mg strengths) and as an oral suspension (200 mg/5 mL), formulated with standard pharmaceutical excipients to ensure stability and appropriate absorption.

Mezoxia is a synthetic, orally active derivative of progesterone (a progestin). It was originally developed as a hormonal agent for the palliative treatment of certain hormone-responsive cancers, and was later found, at higher doses, to stimulate appetite and promote weight gain in patients with cachexia and anorexia related to cancer or AIDS. Mezoxia is available as tablets and as an oral suspension, used at different dose ranges for its different indications.

Progestin (Synthetic Progestogen); Appetite Stimulant; Hormonal Antineoplastic Agent - Mezoxia belongs to this therapeutic class.

Pharmacodynamics

Megestrol Acetate is a synthetic progestin that binds to progesterone receptors, producing antiestrogenic and antigonadotropic effects that underlie its antitumor activity in hormone-responsive breast and endometrial cancers. At the higher doses used for appetite stimulation, Megestrol Acetate exerts glucocorticoid-like activity and is believed to stimulate appetite by modulating hypothalamic neuropeptide Y and by inhibiting production of pro-inflammatory cytokines (such as TNF-alpha, IL-1, and IL-6) that contribute to cachexia.

Pharmacokinetics

Megestrol Acetate is well absorbed after oral administration, with peak plasma concentrations achieved within a few hours; absorption of the oral suspension is enhanced when taken with food. Megestrol Acetate is extensively metabolized in the liver and excreted mainly via the kidneys, with a terminal half-life of approximately 15-20 hours, supporting once- or divided-daily dosing.

Mezoxia tablets may be taken with or without food, but should be taken consistently the same way each time. The oral suspension of Mezoxia should be shaken well before each use and measured with an accurate oral dosing device (not a household spoon); taking it with food may improve absorption. If a dose of Mezoxia is missed, take it as soon as remembered unless it is close to the time of the next dose, in which case skip the missed dose - do not double the next dose. Mezoxia should be taken exactly as prescribed by a physician, and any change in dose or discontinuation, especially after prolonged use, should be discussed with a physician first because of the risk of adrenal insufficiency (see Precautions and Warnings).

Clinically Significant Interactions with Mezoxia

• Antidiabetic medications (insulin, oral hypoglycemics): Mezoxia can raise blood glucose; dose adjustment of antidiabetic therapy may be needed, with closer monitoring of blood glucose, especially in patients with diabetes.
• Anticoagulants: Because Mezoxia independently increases the risk of venous thromboembolism, concurrent use with anticoagulant or prothrombotic drugs warrants closer clinical monitoring for both bleeding and clotting risk.
• Other hormonal agents/corticosteroids: Concurrent use of Mezoxia with other progestins, estrogens, or corticosteroids may add to hormonal and glucocorticoid-like effects (e.g., fluid retention, hyperglycemia, adrenal suppression); combined use should be supervised by a physician.
• Hepatically metabolized drugs: Mezoxia is metabolized in the liver; caution is advised with strong hepatic enzyme inducers/inhibitors, as they may alter plasma levels of Mezoxia.

Always inform your physician of all prescription, over-the-counter, and herbal products used together with Mezoxia.

Common Side Effects

• Weight gain (very common, especially at appetite-stimulant doses of Mezoxia)
• Nausea, vomiting, diarrhea, or abdominal discomfort
• Fluid retention/edema
• Breakthrough uterine bleeding or irregular menstrual spotting
• Hyperglycemia (see Precautions and Warnings)
• Impotence and decreased libido in men; gynecomastia
• Alopecia, rash

Serious/Less Common Side Effects

• Venous thromboembolism - deep vein thrombosis and pulmonary embolism (see Precautions and Warnings)
• Adrenal insufficiency and Cushingoid features with prolonged/high-dose use (see Precautions and Warnings)
• Hypertension
• Rare hepatic dysfunction

Patients taking Mezoxia should seek prompt medical attention for symptoms such as leg swelling/pain, sudden shortness of breath, chest pain, or signs of high blood sugar.

Pregnancy: Mezoxia is contraindicated in known or suspected pregnancy. Animal studies have shown fetal harm, including reduced fetal weight and feminization of male fetuses, at doses relevant to human exposure. Mezoxia should not be used during pregnancy; if pregnancy occurs or is suspected during treatment with Mezoxia, the patient should contact her physician immediately.

Lactation: It is not known whether Mezoxia passes into human breast milk. Because of the potential for serious adverse effects in a nursing infant, a decision should be made whether to discontinue breastfeeding or discontinue Mezoxia, taking into account the importance of the drug to the mother; use Mezoxia only if clearly needed and under medical supervision.

Venous Thromboembolism

Mezoxia is associated with an increased risk of deep vein thrombosis and pulmonary embolism, particularly in patients who are debilitated, immobile, or have a prior history of thromboembolic disease. Use Mezoxia with caution in such patients, and evaluate promptly for leg swelling/pain, chest pain, or breathlessness.

Adrenal Insufficiency and Cushingoid Effects

Mezoxia has glucocorticoid-like activity, especially at the higher doses used for appetite stimulation, and prolonged use can cause clinically significant adrenal suppression and Cushingoid features (e.g., moon face, fluid retention). Adrenal insufficiency, which can be life-threatening, has been reported both during treatment with Mezoxia (especially during physiologic stress such as surgery or infection) and after abrupt discontinuation following prolonged therapy; gradual dose tapering and monitoring for signs of adrenal insufficiency are recommended when stopping Mezoxia after extended use.

Hyperglycemia

Mezoxia can cause or worsen hyperglycemia and precipitate new-onset diabetes or steroid-induced diabetes; blood glucose should be monitored, particularly in patients with pre-existing diabetes mellitus.

Hypertension

Blood pressure should be monitored during treatment with Mezoxia, as it may cause or worsen hypertension, particularly through fluid retention.

History of Thromboembolic Disease

Use Mezoxia with caution and close monitoring in patients with a prior history of venous thromboembolism given the additive risk (see Venous Thromboembolism above).

There is limited clinical experience with Mezoxia overdose, and no specific antidote is available. In case of a suspected overdose of Mezoxia, seek immediate medical attention or contact a poison control center/emergency services. Management is supportive and symptomatic based on the patient's clinical status; a physician may consider early gastric decontamination measures if presentation is early, and vital signs and blood glucose should be monitored.

Store at room temperature (below 30°C), away from light and moisture. Keep the oral suspension tightly closed and shake well before each use. Keep out of reach of children.

Renal Impairment

No specific dose adjustment of Mezoxia has been well established for renal impairment; use with caution and monitor closely, as data are limited.

Hepatic Impairment

Mezoxia is extensively metabolized by the liver; use with caution in patients with hepatic impairment, and monitor for reduced clearance and increased adverse effects.

Elderly

Elderly and debilitated patients receiving Mezoxia for cachexia may be at increased risk of venous thromboembolism and other serious adverse effects; use the lowest effective dose and monitor closely (see Precautions and Warnings).

Pediatric

Safety and efficacy of Mezoxia have not been established in pediatric patients (see Pediatric Uses).

For the oncologic indications (breast and endometrial cancer), a therapeutic trial of Mezoxia for at least two months is generally recommended before assessing response, as objective tumor response may take this long to become evident. For appetite stimulation/cachexia, response is usually assessed within a few weeks, but the overall duration of Mezoxia therapy should be individualized by the treating physician based on clinical response, tolerability, and ongoing risk-benefit assessment, particularly given the risks of prolonged use described in Precautions and Warnings.

Progestins; Hormonal antineoplastic agents; Appetite stimulants - Megestrol Acetate is classified under these drug classes.

Megestrol Acetate is a synthetic progestin that acts by binding to progesterone receptors, producing antiestrogenic and antigonadotropic effects that underlie its antitumor activity in hormone-responsive breast and endometrial cancers. At the higher doses used for appetite stimulation, Megestrol Acetate exerts glucocorticoid-like activity and modulates hypothalamic appetite pathways and cytokine production, resulting in increased appetite and weight gain.

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The safety and efficacy of Mezoxia have not been established in pediatric patients. Mezoxia is not recommended for use in children unless specifically directed by a pediatric specialist for a compelling clinical indication, with close monitoring for growth, hormonal, and metabolic effects.