Eulexin 250 mg Capsules

Brand Name

The medication is commercially known as Eulexin, a name well-established in the realm of hormonal treatments for specific medical conditions.

International Nonproprietary Name (INN)

The active pharmaceutical ingredient in this product is identified globally as flutamide, a designation that ensures uniformity in medical documentation and practice worldwide.

Form of Release

Eulexin is manufactured in the form of capsules, crafted for oral administration. These capsules typically contain 125 mg of the active substance and are often supplied in bottles or blister packs, depending on regional packaging preferences.

Composition

Each capsule of Eulexin contains 125 mg of flutamide as its core active component. The formulation is supported by several inactive ingredients, including microcrystalline cellulose, which acts as a filler to provide structural integrity, and lactose monohydrate, contributing to the capsule’s consistency. Additional excipients such as sodium lauryl sulfate enhance solubility, while the capsule shell is composed of gelatin, titanium dioxide, and iron oxides, lending it a distinctive yellowish-brown hue. Small quantities of other stabilizers may also be included to preserve the drug’s quality throughout its shelf life.

Pharmacologic Properties

Pharmacodynamics

Eulexin operates as a non-steroidal anti-androgen, exerting its effects by competitively binding to androgen receptors in target tissues, most notably within the prostate. This interaction prevents androgens like testosterone and dihydrotestosterone (DHT) from stimulating these receptors, which play a pivotal role in the growth of prostate cancer cells. By inhibiting this androgen-driven proliferation, the medication slows the progression of hormone-sensitive malignancies, making it a valuable tool in managing advanced prostate cancer. Unlike treatments that suppress androgen production, it focuses solely on receptor blockade, leaving testicular testosterone synthesis intact.

This receptor inhibition triggers a feedback mechanism in the hypothalamic-pituitary axis, increasing luteinizing hormone (LH) secretion and subsequently elevating circulating testosterone levels. While this rise does not undermine the drug’s efficacy, it differentiates its action from androgen-suppressing therapies. Clinical observations indicate a rapid reduction in prostate-specific antigen (PSA) levels, a critical indicator of disease activity, often within days to weeks of starting treatment. Its targeted approach makes it particularly effective when paired with luteinizing hormone-releasing hormone (LHRH) agonists to achieve comprehensive androgen deprivation.

Pharmacokinetics

Following oral intake, Eulexin is swiftly absorbed from the gastrointestinal tract, with peak plasma concentrations of its active metabolite, hydroxyflutamide, occurring within 1 to 2 hours. The presence of food does not significantly alter its absorption, allowing for flexible administration timing. The drug demonstrates moderate plasma protein binding, around 94%, which influences its distribution primarily to blood and androgen-dependent tissues.

Metabolism takes place predominantly in the liver, where cytochrome P450 enzymes, particularly CYP1A2, convert flutamide into hydroxyflutamide, the metabolite responsible for most of its anti-androgenic activity. This process is rapid, with the parent compound having a short half-life of about 5 to 6 hours, while the metabolite persists slightly longer. Elimination occurs mainly through urine, with over 90% of the dose excreted as metabolites within 72 hours, and minimal amounts appearing in feces. The quick turnover supports its thrice-daily dosing regimen, ensuring consistent receptor blockade.

Indications for Use

Eulexin is primarily indicated for the treatment of metastatic prostate cancer in adult men. It is most commonly used in combination with LHRH agonists, such as leuprolide or goserelin, to achieve complete androgen blockade, targeting both testicular and adrenal androgen sources. This combined strategy is especially beneficial for patients with advanced disease, helping to control cancer spread and alleviate symptoms like bone pain or urinary difficulties.

In certain cases, the medication may be employed as part of initial therapy to counteract the testosterone flare associated with LHRH agonists, a temporary surge that can exacerbate symptoms before suppression takes effect. While its primary role is in metastatic settings, some clinicians may explore its use in locally advanced cases under specific circumstances, though such applications typically require careful justification and oversight.

Contraindications

Eulexin is not intended for use in women or children, as its mechanism is tailored to male androgen pathways and has no relevance in other populations. It is contraindicated in individuals with known hypersensitivity to flutamide or any capsule component, such as lactose, where reactions could range from skin irritation to severe allergic responses.

Severe liver dysfunction represents a major barrier to its use, given the drug’s extensive hepatic metabolism. Patients with active liver disease or a history of significant hepatotoxicity from related agents should avoid this therapy, as it could worsen existing conditions or lead to dangerous drug accumulation. Additionally, those with hemoglobinopathies like methemoglobinemia must refrain from treatment due to rare but documented risks of this condition worsening.

Method of Administration and Dosage

Administration Guidelines

The capsules should be taken orally, swallowed whole with water to ensure smooth passage to the stomach. They can be consumed with or without meals, offering convenience for patients in scheduling doses. Splitting or chewing the capsules is not recommended, as it may disrupt absorption and expose the mouth to unnecessary irritation.

Dosage for Adults and Children

For adult men with prostate cancer, the standard dose of Eulexin is 250 mg (two 125 mg capsules) taken three times daily, totaling 750 mg per day. This regimen is typically initiated alongside an LHRH agonist to synchronize androgen suppression and mitigate the initial testosterone flare. Maintaining regular intervals—approximately every 8 hours—helps sustain effective drug levels. Children are not candidates for this therapy, as it addresses conditions exclusive to adult males.

Dose Adjustment in Specific Conditions

No specific dose adjustments are required for renal impairment, as the kidneys play a secondary role in elimination compared to the liver. In mild to moderate hepatic dysfunction, the standard dose may still be used, but close monitoring of liver function is essential due to the risk of toxicity. Severe liver impairment precludes use entirely, and no tailored adjustments exist for lesser degrees of compromise, emphasizing the need for regular hepatic assessments during treatment. Elderly patients generally follow the same dosing unless comorbidities necessitate reevaluation.

Side Effects

Eulexin may cause a range of side effects, though many patients tolerate it with minimal disruption. Frequently reported reactions include hot flashes, a common consequence of androgen receptor blockade, and gastrointestinal issues like diarrhea or nausea, which often subside over time. Gynecomastia or breast tenderness affects a significant portion of users, reflecting unopposed estrogen activity in the absence of androgen signaling.

Sexual dysfunction, such as diminished libido or impotence, is another possible outcome, though its severity varies widely. Liver function changes, including elevated transaminases, occur in some cases and require periodic blood tests to detect early signs of hepatotoxicity. Rare but serious effects, such as methemoglobinemia or severe liver injury, have been noted, prompting immediate discontinuation and medical evaluation if symptoms like cyanosis or jaundice appear.

Overdose

Symptoms of Overdose

Excessive intake of Eulexin may not produce immediate, dramatic symptoms due to its pharmacokinetic profile. Experimental data suggest doses up to 1,500 mg daily—double the standard amount—cause no acute emergencies, though prolonged excess could amplify side effects like diarrhea, fatigue, or liver strain. Specific overdose manifestations are not well-defined, given the drug’s rapid metabolism.

First Aid Measures

If an overdose is suspected, medical advice should be sought promptly, though urgent action is seldom necessary. No specific antidote is available, so care focuses on supportive measures, such as monitoring vital signs and liver parameters, and managing any discomfort. The drug’s short half-life limits the duration of effects, but observation remains key until stability is confirmed.

Drug Interactions

Effects on Other Medications

Eulexin can affect drugs metabolized by CYP1A2, as it induces this enzyme’s activity. For example, co-administration with theophylline may accelerate its clearance, potentially reducing efficacy and requiring dose adjustments. Warfarin’s anticoagulant effect might also be enhanced, necessitating closer monitoring of clotting times. Use with LHRH agonists shows no significant pharmacokinetic interference, supporting their combined application in prostate cancer management.

Enzyme inducers like phenytoin could theoretically hasten flutamide metabolism, though clinical relevance is minimal. Patients should inform their healthcare provider of all medications to evaluate potential interactions thoroughly.

Compatibility with Alcohol and Food

Alcohol does not directly impact the drug’s performance, allowing moderate consumption without concern for altered effects. Food intake has little bearing on absorption, so the medication can be taken with meals or on an empty stomach, accommodating patient preferences seamlessly.

Special Precautions

Use During Pregnancy and Breastfeeding

Eulexin is designated for male use only and is contraindicated in women, particularly during pregnancy. While not directly relevant to female patients, men taking the drug should prevent pregnant partners from handling capsules, as theoretical risks of skin absorption remain unstudied. Breastfeeding considerations are inapplicable, as the therapy targets men, and its presence in breast milk has not been investigated.

Men on this treatment face no specific fertility restrictions beyond those tied to their underlying condition. Discussing reproductive plans with a physician is advisable, given the hormonal nature of the therapy and disease context.

Impact on Driving and Operating Machinery

The medication typically does not affect mental alertness or physical coordination, making it safe for most patients to drive or operate machinery. Fatigue or rare dizziness in some individuals suggests a cautious approach during initial use until personal tolerance is established.

Considerations for Elderly and Pediatric Populations

Elderly men, a primary group for prostate cancer treatment, generally respond well to Eulexin, with no significant differences in efficacy or safety compared to younger adults. Age-related liver function decline could increase sensitivity in some cases, warranting regular monitoring. Pediatric use is not permitted, as the drug’s purpose and safety profile are untested in children and irrelevant to their health needs.