Truqap | Pharmacology Mentor

Generic Name

Truqap

Mechanism

Dupilumab is a fully human IgG4 monoclonal antibody that binds to the α subunit of the IL‑4 receptor (IL‑4Rα).
By blocking IL‑4Rα, the drug inhibits signaling of both IL‑4 and IL‑13, two cytokines central to Th2‑mediated inflammation.
The downstream effects include:
Reduced keratinocyte proliferation and cytokine release in AD.
Decreased airway hyperreactivity in eosinophilic asthma.
Lowered IgE production and eosinophil recruitment.

Pharmacokinetics

Administration: Subcutaneous injection (clinical use).
Absorption: Rapid absorption; peak concentrations within 6–10 days.
Distribution: Large volume of distribution (~271 L); full penetration of skin tissues.
Metabolism: Catabolized via proteolytic pathways; no significant hepatic enzyme involvement.
Elimination: T₁/₂ ≈ 21 days; steady‑state achieved after ~16 weeks of twice‑monthly dosing.
Special Populations: No dose adjustment necessary for renal or hepatic impairment; pregnancy category B.

Indications

Moderate‑to‑severe atopic dermatitis (persistent, symptomatic, or refractory to topical therapy).
Uncontrolled moderate‑to‑severe asthma with a type 2 (eosinophilic) phenotype.
Allergic rhinitis (in certain regulatory approvals).

Contraindications

Category	Details
Contraindications	Known hypersensitivity to dupilumab or any component.
Warnings	• Possible ocular surface disease (conjunctival hyperemia, keratitis). • Potential for headache, arthralgia, and injection‑site reaction.
Precautions	• Monitor for signs of infection; no global immunosuppression. • Use with caution in patients on biologics for other immune disorders.

Dosing

Initial Dose (Adults/Children ≥12 yrs): 600 mg SC (two 300 mg pre‑filled syringes) at baseline.
Maintenance: 300 mg SC every 2 weeks thereafter.
Children (ages 6–11 yrs): 200–300 mg SC every 4 weeks, depending on weight-based dosing.
Injection sites: Thigh, abdomen, upper arm – rotate to avoid local reactions.
Pre‑treatment screening: Complete blood count, liver enzymes; baseline eye exam recommended.

Adverse Effects

Common
Injection‑site reaction (pain, erythema, pruritus) – most frequent.
Headache, arthralgia, myalgia.
Upper respiratory tract infections.
Conjunctival hyperemia (symptomatic ocular inflammation).
Serious
Systemic infections: eczema herpeticum, tuberculosis (rare).
Severe ocular events: keratitis, uveitis.
Hypersensitivity reactions: rash, urticaria, anaphylaxis.
Peripheral eosinophilia – monitor CBC.

Monitoring

Clinical: Photographs of skin lesions, pruritus scores; periodic asthma symptom assessment.
Laboratory: CBC (particularly eosinophils) at baseline and every 8 weeks; liver function tests at baseline and every 3 months.
Ophthalmology: Baseline exam; follow‑up if symptomatic ocular irritation.
Patient‑reported: Injection‑site home care diary; monitoring for new onset of respiratory symptoms.

Clinical Pearls

Pearl	Action
Rapid Efficacy	The first visible improvement in AD can be seen as early as 2–4 weeks; consider encouraging adherence even if the 75% improvement threshold is not immediately reached.
Injection‑Site Management	Use gentle pressure after injection; avoid prolonged skin compression; educate patients on proper rotation to minimize local reactions.
Eosinophilia as a Biomarker	A transient rise in peripheral eosinophils is expected; persistent elevation >5000 cells/µL warrants evaluation for secondary infection or systemic disease.
Transition to Maintenance	Cease the initial 600 mg loading dose if a patient fails to exhibit adequate response in the first 6 weeks; adjust to 300 mg SC Q2W.
Pregnancy & Lactation	While pregnancy category B, discontinue if pregnancy is confirmed because of insufficient safety data; breastfeeding not contraindicated but data are limited.
Combination with Topicals	Maximize topical steroid or calcineurin inhibitor use for broader skin coverage during dupilumab therapy; a synergistic effect is often observed.

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• Note: This drug card is intended as a reference for medical students and practitioners. For prescribing, always refer to the latest clinical guidelines, drug monograph, and local regulatory requirements.