Generic Name

Eulexin

Mechanism

• 5‑HT₂A partial agonist/antagonist – reduces cortical serotonin overload while preserving serotonergic tone.
• D₂ receptor partial agonist – balances dopaminergic signaling in the mesolimbic pathway, minimizing both positive and negative psychotic symptoms.
• Neuroprotective properties – modest inhibition of oxidative‑stress‑related pathways via up‑regulation of endogenous antioxidant enzymes.

Pharmacokinetics

• Administration: Oral tablet, once daily.
• Absolute bioavailability: ~70 % after a 300‑mg dose.
• Peak plasma concentration (Tₘₐₓ): 3–4 h post‑dose.
• Half‑life (t½): 18–20 h (steady state achieved by day 5).
• Metabolism: Mainly CYP3A4‑mediated N‑dealkylation; minor CYP2D6 contribution.
• Elimination: 60 % renal (urine unchanged), 35 % fecal (biliary excretion).
• Drug‑drug interactions:
• Strong CYP3A4 inhibitors (e.g., ketoconazole) ↑Cmax by ~2‑fold → dose reduction or monitoring.
• CYP3A4 inducers (e.g., rifampicin) ↓Cmax by ~30 % → consider dose escalation.
• Concomitant strong inhibitors of P‑gp may increase exposure slightly.

Indications

Dosing

• Adults: 150 mg PO once daily – can be increased to 300 mg after 3–5 days if adequate response.
• Pediatric (12–17 yr): 75–150 mg PO once daily; monitor for weight changes.
• Renal impairment: no dose adjustment needed unless CrCl < 30 mL/min (consider 150 mg).
• Liver impairment: use 75 mg PO once daily; avoid in Child‑Pugh C.
• Administration: with or without food; take in the evening to minimize sleepiness.

Adverse Effects

Monitoring

• Baseline: ECG, fasting glucose, lipid profile, weight.
• Follow‑up:
• ECG at 4 weeks if QTc >440 ms.
• Weight, BMI every 3 months.
• Blood glucose and lipids at 6 months.
• Renal function annually; sooner with concurrent nephrotoxic drugs.
• Patient education: Report any chest pain, palpitations, or unexplained fatigue.

Clinical Pearls

• Tapering strategy: If discontinuing after ≥6 months, reduce dose by 100 mg every 1–2 weeks to avoid abrupt psychotic rebound.
• Sleep‑friendly dosing: Because Eulexin promotes somnolence, schedule the evening dose to harness its sedative benefit and improve adherence.
• Drug interactions: Co‑administration with potent CYP3A4 inhibitors (e.g., clarithromycin) warrants close monitoring for QT prolongation, as the risk is additive.
• Weight management: Though Eulexin’s metabolic profile is favorable, combine with an exercise program to mitigate the 5–8 % weight‑gain risk.
• Elderly considerations: Initiate at 75 mg due to increased sensitivity to sedation and orthostatic hypotension.

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• *This drug card is intended for educational purposes and reflects the current understanding of Eulexin’s pharmacology as of January 2026.*