Miltefosine
**Miltefosine** is an oral **antileishmanial** agent primarily used in veterinary medicine to treat **canine leishmaniasis (CanL)**, a severe systemic disease caused by the intracellular protozoan *Leishmania infantum*. - Originally developed as an **antineoplastic** (anti-cancer) drug. - **Clinical Pearl**: While it significantly reduces the parasitic load and improves clinical signs, it rarely achieves complete parasitological cure. Remission is the primary therapeutic goal. - Efficacy is markedly improved when used in combination with **allopurinol**. - It is an orphan drug in human medicine and is not commercially available as a veterinary-labeled product in the USA, though it is widely used in endemic regions (e.g., Europe).
Mechanism: Miltefosine is an **alkylphosphocholine** (phospholipid derivative). Its exact mechanism against *Leishmania* is multifactorial: - **Inhibits macrophage penetration**: Interacts with **glycosomes** and **glycosylphosphatidyl-inositol (GPI) anchors** that are essential for the parasite's intracellular survival. - **Enzyme inhibition**: Inhibits **phospholipase** → disrupts parasite membrane signal transduction and lipid metabolism. - **Apoptosis induction**: Triggers apoptosis-like cell death in the parasite by disrupting lipid rafts in the cell membrane. - Additionally, miltefosine exhibits mild antineoplastic, immunomodulatory, and antiviral properties.
Dosing by species
- Canine leishmaniasis · 2 mg/kg PO · PO · once a day · 28 days · Poured onto food, with a full or partial meal.
- Canine leishmaniasis (alternative treatment to meglumine antimoniate) · 2 mg/kg PO · PO · once daily · 28 days · Use with allopurinol (10 mg/kg PO q12h, orally for at least 6 months).
- Leishmaniosis · 2 mg/kg · PO · q24h · 28 days · It is particularly important that the full course is completed and given with allopurinol. Pour on feed to reduce digestive side effects.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Hypersensitivity to miltefosine
- Pregnant animals
- Lactating animals
- Breeding animals
- Pregnancy
- Lactation
Adverse effects
- Vomiting (most common)
- Diarrhea
- Inappetence
- Potential nephrotoxicity
- Potential hepatotoxicity
- Vomiting (moderate, transient)
- Diarrhoea (moderate, transient)
Monitoring
- Baseline and periodic renal function
- Hepatic enzymes
- Adverse effects (especially vomiting)
- Patient weight
- Clinical signs of leishmaniosis
- Gastrointestinal signs (vomiting, diarrhoea)
Overdose
Overdoses are likely to cause severe **gastrointestinal signs** (vomiting, diarrhea, anorexia). In cases of massive overdose, there is a potential for **hepatic, renal, and retinal toxicity**. There is **no specific antidote** for miltefosine overdose; treatment should consist of prompt gastrointestinal decontamination (if recent and patient is asymptomatic) followed by aggressive supportive care (IV fluids, antiemetics, hepatoprotectants).
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.