Meglumine Antimoniate
Meglumine antimoniate is a **pentavalent antimony** compound primarily used for the treatment of **canine leishmaniasis** (caused by *Leishmania infantum*). * **Combination Therapy**: It is frequently used in combination with **allopurinol** to achieve synergistic effects, improve clinical outcomes, and reduce the risk of antimonial drug resistance. * **Eradication**: Complete eradication of *Leishmania* organisms is rarely achieved; the goal of therapy is clinical remission and reduction of parasite load. * **Availability**: It is not commercially available or approved in the USA, but is widely used in Mediterranean and South American countries where leishmaniasis is endemic. In the US, it may be obtained via the CDC or legal importation for compassionate use. > **Clinical Pearl**: Because *Leishmania* amastigotes reside within host macrophages, the drug must penetrate these immune cells to exert its leishmanicidal effects. Treatment is typically prolonged and requires careful monitoring of renal function.
Mecanismo: Meglumine antimoniate selectively inhibits leishmanial enzymes required for **glycolytic and fatty acid oxidation** → disruption of parasite bioenergetics → decreased ATP production → death of the organism. * **Synergy**: When used with allopurinol (a leishmaniostatic agent that disrupts RNA synthesis), the combination provides synergistic efficacy and helps prevent the emergence of resistant strains. * **Mechanistic Pearl**: While the exact mechanism remains partially elucidated, it is widely believed that pentavalent antimony (SbV) acts as a prodrug and is reduced to the more toxic and active **trivalent antimony (SbIII)** within the acidic environment of the macrophage phagolysosome, where the amastigotes reside.
Dosificación por especie
- Leishmaniosis (off-label) · 50 mg/kg · SC · q24h · 3-4 weeks · Use with extreme caution; cats may be more sensitive to toxicity.
- Leishmaniasis (First line treatment) · 75-100 mg/kg SC once daily for 4-8 weeks, with allopurinol (10 mg/kg PO twice daily for at least 6-12 months. · SC · q24h · 4-8 weeks · Used in combination with allopurinol.
- Leishmaniasis · 100 mg/kg SC daily for 3-4 weeks; better results are obtained with longer durations (4-6 weeks) of treatment. Protocol with allopurinol may reduce relapse rates: meglumine antimoniate as above with allopurinol at 20-40 mg/kg PO daily for a minimum of 3 weeks. Followed with long-term treatment with allopurinol (alone) at 20-40 mg/kg PO daily or intermittently (one week treatment per month). · SC · q24h · 3-6 weeks · Longer duration (4-6 weeks) yields better results.
- Leishmaniasis · 100 mg/kg/day SC until resolution; with allopurinol at 20 mg/kg PO q12h for 9 months. · SC · q24h · Until resolution · Used in combination with allopurinol.
- Leishmaniosis · 75-100 mg/kg · SC · q24h (or divided q12h) · 3-4 weeks · Often used in combination with allopurinol (10 mg/kg PO q12h for 6-12 months).
Las dosis son una referencia clínica para veterinarios colegiados. Confirme siempre con la ficha técnica vigente y el paciente individual.
Vías de administración
Contraindicaciones
- Previous hypersensitivity to meglumine antimoniate
- Severe renal, hepatic, or cardiac failure (relative contraindication; weigh risks vs. benefits)
- Severe renal impairment
- Hepatic failure
- Cardiac disease
Efectos adversos
- Injection site reactions (cutaneous abscesses, cellulitis, pain)
- Lethargy
- Gastrointestinal effects (inappetence, vomiting)
- Transient increases in liver enzymes
- Nephrotoxicity (tubular damage, proximal tubule cell vacuolization, coagulative necrosis)
- Pain and swelling at the injection site
- Nephrotoxicity (proteinuria, elevated BUN/creatinine)
- Anorexia
- Vomiting
- Hepatotoxicity (rare)
- Myalgia/arthralgia
Interacciones farmacológicas
- Agents that can prolong QT interval (e.g., tricyclic antidepressants, disopyramide, quinidine, procainamide) · Meglumine antimoniate may prolong QT interval further with increased risk for arrhythmias
- Aminoglycosides · Increased risk of nephrotoxicity · major
- NSAIDs · Increased risk of nephrotoxicity · moderate
Monitorización
- Efficacy (PCR preferred)
- CBC (baseline and periodic)
- Liver enzymes (baseline and periodic)
- Renal function tests (serum creatinine, BUN) (baseline and periodic)
- Serum lipase and amylase (baseline and periodic)
- Urinalysis (baseline and periodic)
- Urinalysis (specifically for proteinuria/UPC ratio)
- BUN and Creatinine
- Liver enzymes (ALT, AST, ALP)
- Complete Blood Count (CBC)
- Clinical signs of injection site reactions
Sobredosis
No specific overdose information is available. Depending on the dosage, a single massive overdose could potentially cause **renal, hepatic, pancreatic, and hematologic toxicity**. Clinically, **gastrointestinal effects (severe vomiting)** and **profound lethargy** would be the most likely immediate outcomes. *Management*: Observe the patient closely, provide supportive care (IV fluids to protect renal function), and contact an animal poison control center for further guidance.
La referencia de fármacos de VetSheet está destinada a veterinarios colegiados como apoyo a la decisión clínica, no sustituye el juicio profesional ni la ficha técnica vigente del fabricante.