Delzicol
Delzicol
Generic Name
Delzicol
Mechanism
- Fast‑acting 5‑HT₃ blockade: Ondansetron competitively binds to central and peripheral 5‑HT₃ receptors, preventing serotonin‑induced activation of the vomiting centre in the medulla and the chemoreceptor trigger zone.
- Result: Rapid suppression of nausea, vomiting, and dizziness with a half‑life of 4–5 h.
Pharmacokinetics
| Parameter | Typical Values | |
| Absorption | Oral bioavailability ~95 %; peak plasma 30‑60 min | |
| Distribution | Vd 0.4 L/kg, 44 % protein binding | |
| Metabolism | Primarily CYP3A4 (≈70 %) and CYP2D6; active metabolite CG‑4987 <2 % | |
| Elimination | 80 % renal, 20 % biliary | |
| Half‑life | 4–5 h (adult); 24 h in neonates | |
| Special | Hepatic dysfunction lengthens t½; pregnancy category B |
Indications
- Chemotherapy‑induced nausea & vomiting (CINV)
- Post‑operative, post‑anesthetic, or radiation‑related emesis
- Acute motion sickness and vestibular vertigo (pediatrics & adults)
- Opioid‑related nausea & vomiting (adjunctive)
- Migraine‑associated nausea when combined with triptans
Contraindications
- Absolute: Hypersensitivity to ondansetron or any formulation excipients (e.g., lactose, magnesium stearate).
- Relative: Severe hepatic impairment (Child‑Pugh B/C) or renal insufficiency requiring dose adjustment.
- Warnings:
- QTc prolongation – risk increased with other QT‑prolonging drugs (macrolides, fluoroquinolones) or congenital long QT syndrome.
- Serotonin syndrome – avoid when co‑administered with MAO inhibitors, SSRIs, SNRIs, tramadol, or linezolid.
Dosing
| Population | Dose | Route & Timing | Notes |
| Adults (≥18 y, ≤70 kg) | Chemotherapy | 8 mg IV 30–60 min pre‑chemo | 8‑mg IV or 4‑mg PO; repeat q8h if vomiting occurs |
| Acute/emergency | 4 mg PO or IV, 2–4 × /24 h | Max 12 mg/day | |
| Motion sickness | 2 mg PO at onset; 4 mg 6–8 h later | ||
| Pediatrics (1–17 y) | 0.1 mg/kg (max 4 mg) | IV/PO 30–60 min before chemo | 0.2 mg/kg for breakthrough emesis (max 4 mg) |
| Acute motion sickness | 1 mg/kg (max 4 mg) | ||
| Neonates/Infants (>1 mo) | 0.04 mg/kg IV (max 4 mg) | 30–60 min before chemo | Avoid under 1 month |
| Method | Tablets (4 mg), or oral solution (1 mg/mL) | Oral dissolution in 250 mL water (pediatric) |
• IV/IM supply: 4 mg/mL
• Use a syringe with milliliter marks for accurate pediatric dosing.
Adverse Effects
- Common (≥5 %)
- Headache, dizziness
- Constipation, abdominal cramps
- Fatigue, mild fever
- Serious (rare)
- QTc prolongation → Torsades de Pointes
- Severe hypotension (rare)
- Serotonin syndrome in poly‑serotonergic regimens
- Allergic reactions (rash, swelling)
Monitoring
- Baseline ECG for patients on QT‑prolonging agents.
- Serum electrolytes (K⁺, Mg²⁺, Ca²⁺) in long‑term therapy or cardiac patients.
- Liver function tests every 4 weeks for chronic users.
- Observe for serotonin syndrome if combined with SSRIs/MAOIs/other serotonergic drugs (hyperreflexia, tremor, clonus).
Clinical Pearls
- Rapid pre‑chemotherapy dosing: 8 mg IV 30 min before high‑risk chemo yields optimal antiemetic control without increasing adverse events.
- Pediatric dosing precision: Weight‑based 0.1 mg/kg (max 4 mg) avoids unnecessary tablet wastage – use the diluted solution for infants <5 kg.
- Avoid poly‑serotonergic cocktails: In patients on SSRIs or SNRIs, limit ondansetron to 4 mg and monitor closely for serotonin syndrome.
- QTc vigilance: If the patient also receives fluoroquinolones or macrolides, consider a 0.1 mg/kg dose or switch to a non‑serotonergic antiemetic (e.g., dexamethasone + metoclopramide).
- Non‑use in severe hepatic disease: In Child‑Pugh C, avoid due to prolonged half‑life and limited data.
--
• Key Takeaway:
Delzicol (ondansetron) is a rapid‑acting, well‑tolerated antiemetic that effectively reduces nausea and vomiting in chemotherapy, postoperative, and motion‑sickness settings when used with weight‑based dosing, careful monitoring for QTc changes, and avoiding serotonergic drug interactions.