1. Clinical Overview
A fixed-dose combination (FDC) of a macrocyclic lactone anthelmintic (Ivermectin) and a benzimidazole carbamate anthelmintic (Albendazole). This combination provides a broad-spectrum, synergistic effect against a wide range of nematode (roundworm) infections, particularly effective in community-based Mass Drug Administration (MDA) programs for Lymphatic Filariasis (LF) elimination in India. Ivermectin acts on glutamate-gated chloride channels, while Albendazole inhibits microtubule polymerization.
| Onset | Duration | Bioavailability |
|---|---|---|
| Ivermectin: Plasma levels peak in ~4 hours. Albendazole (as Albendazole sulfoxide): Plasma levels peak in ~2-3 hours. Anthelmintic effect begins within hours. | Ivermectin: Single dose provides sustained antiparasitic effect for days to weeks. Albendazole: Therapeutic effect persists for the duration of the standard treatment course. | Ivermectin: ~50% under fasting conditions, increased ~2.5x with a high-fat meal. Albendazole: Poor (<5%); its active metabolite Albendazole sulfoxide has ~70% bioavailability, also increased with fatty meals. |
2. Mechanism of Action
The combination exerts a synergistic anthelmintic effect through two distinct mechanisms. Ivermectin binds with high affinity to glutamate-gated chloride channels (GluCl) found in nerve and muscle cells of invertebrates. This binding increases cell membrane permeability to chloride ions, leading to hyperpolarization, paralysis, and death of the parasite. Albendazole and its active metabolite Albendazole sulfoxide bind to parasite beta-tubulin, inhibiting microtubule polymerization. This disrupts glucose uptake, depletes energy stores (ATP), and inhibits cell division (mitosis), leading to larval degeneration and impaired motility of adult worms.
3. Indications & Uses
- Mass Drug Administration (MDA) for elimination of Lymphatic Filariasis (caused by Wuchereria bancrofti)
- Treatment of Soil-Transmitted Helminthiasis (STH) - Ascariasis (Roundworm), Trichuriasis (Whipworm), Hookworm (Ancylostoma duodenale, Necator americanus)
- Strongyloidiasis (off-label in combination, though Ivermectin is primary)
4. Dosage & Administration
Adult Dosage: For Lymphatic Filariasis MDA & STH: A SINGLE oral dose of Ivermectin (12mg) + Albendazole (400mg), repeated annually in endemic areas. For Strongyloidiasis (off-label): May require repeated doses (e.g., Ivermectin 200 mcg/kg single dose, repeated after 2 weeks).
Administration: Administer orally with a full glass of water. SHOULD BE TAKEN WITH FOOD, preferably a fatty meal, to significantly enhance the absorption of both drugs. Tablets may be chewed, crushed, or swallowed whole.
5. Side Effects
Common side effects may include:
- Headache
- Dizziness
- Nausea
- Abdominal pain/discomfort
- Diarrhea
- Transient elevation of liver enzymes (AST/ALT)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Rifampicin / Rifabutin | Potent CYP3A4 inducer; may significantly decrease Ivermectin plasma concentrations, reducing efficacy. | Major |
| Phenytoin / Carbamazepine | CYP3A4 inducers; may decrease Ivermectin levels. | Moderate |
| Cimetidine | May increase plasma levels of Albendazole sulfoxide by inhibiting its metabolism. | Moderate |
| Dexamethasone / Praziquantel | May increase plasma levels of Albendazole sulfoxide. | Moderate |
| Warfarin | Albendazole may potentially affect INR; monitoring recommended. | Moderate |
| Theophylline | Ivermectin may potentially inhibit its metabolism; monitor levels. | Minor |
7. Patient Counselling
- DO take this medicine with food, preferably a meal containing fats/oil.
- DO complete the full course as prescribed, even if symptoms improve.
- DO inform your doctor if you are pregnant, planning pregnancy, or breastfeeding.
- DO inform your doctor about all other medicines you are taking.
- DO NOT take a double dose if you miss one. Consult your doctor.
- DO NOT drive or operate heavy machinery if you feel dizzy after taking the medicine.
8. Toxicology & Storage
Overdose: Symptoms may include exaggerated pharmacologic effects: Severe nausea, vomiting, diarrhea, abdominal pain, dizziness, ataxia, lethargy, pupillary dilation, hypotension, bronchospasm, and potentially seizures (with massive overdose).
Storage: Store below 30°C. Protect from light and moisture. Keep the tablet in the blister strip until use. Keep out of reach of children.