Meglumine antimoniate !

Injectable pentavalent antimonial, the mainstay for cutaneous leishmaniasis in Colombia; heart, pancreas and liver are watched.

Updated 2026-11-01

Class: Antileishmanials
Enzyme: Leishmania trypanothione reductase (and the parasite's thiols)
ATC code: P01CB01
WHO Model List of Essential Medicines

Also called: Meglumine antimonate, N-methylglucamine antimoniate

Leishmania trypanothione reductase (and the parasite's thiols)Meglumine antimoniate

The figure shows Leishmania infantum trypanothione reductase with trivalent antimony (Sb³⁺) bound, the active form the pentavalent antimonial turns into.

Target in 3D: Leishmania trypanothione reductase (and the parasite's thiols). PDB structure 2W0H (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

Pentavalent antimony (Sb⁵⁺) is a prodrug: inside the macrophage and the amastigote it is reduced to the more toxic trivalent antimony (Sb³⁺). Sb³⁺ drives trypanothione and glutathione out of the parasite and inhibits trypanothione reductase, the enzyme that keeps its antioxidant defence working. Without reducing power the amastigote dies inside the phagolysosome.

Sb⁵⁺ reaches the infected macrophage
It is reduced to Sb³⁺, the active form
Sb³⁺ drains thiols and inhibits trypanothione reductase
The amastigote dies of oxidative stress

Pharmacokinetics

Absorption: Not absorbed orally: given IM, IV or intralesionally
Distribution: Distributes quickly; antimony builds up in tissues and leaves slowly
Elimination: In urine
Half-life: Two phases: a short initial one of hours and a much longer terminal one

Indications

Cutaneous leishmaniasis (first-line systemic treatment in adults in Colombia) Leishmaniasis →
Localised cutaneous leishmaniasis with few lesions: intralesional infiltration Leishmaniasis →
Mucosal and disseminated leishmaniasis Leishmaniasis →
Visceral leishmaniasis, as second line Leishmaniasis →

Adverse effects

Common

Muscle and joint pain
Nausea, abdominal pain and other gut symptoms
Fever, headache, weakness and malaise
Skin rash
Pain at the IM injection site and sterile abscesses
Raised transaminases, amylase and lipase

Contraindications

Pregnancy
Electrocardiogram abnormalities
Significant heart, kidney or liver disease (specialist assessment; local treatments or liposomal amphotericin B are preferred)
Hypersensitivity to antimonials

Key interactions

Other QT-prolonging drugs: Add to the risk of ventricular arrhythmias
Concurrent tuberculosis treatment: The Colombian guidance asks for close watch for adverse events from interactions

What is monitored

Electrocardiogram before and during treatment (over 45 years or with heart disease)
Transaminases, amylase and lipase at mid-course and at the end
Blood count, creatinine and urea
Pregnancy test in women of childbearing age
Body weight and ulcer size (measurements or photographs)

Administration and safety

IM or IV once daily; in Colombia it is supervised treatment.
Intralesional infiltration is done by trained staff, like an intradermal or subcutaneous injection covering the whole ulcer.
IM injection is painful and may leave sterile abscesses: rotate sites.
Once the case is confirmed and treatment chosen, it is notified to SIVIGILA.

Nursing care

Before: ECG when indicated, baseline labs and pregnancy test.
Ask about muscle, joint or abdominal pain (possible pancreatitis) and about palpitations or fainting.
Weigh the patient: weight sets the dose and may change during treatment.
Record how the ulcer evolves and the later follow-up visits (cure or failure).
Adverse events are reported to INVIMA (pharmacovigilance).

Pregnancy and breastfeeding

Not recommended in pregnancy; thermotherapy is used or treatment is postponed, and if urgent liposomal amphotericin B is used.

Test yourself

Think of the answer, then tap the question to see it.

What is the active form of meglumine antimoniate?

Trivalent antimony (Sb³⁺), formed when pentavalent antimony is reduced inside the macrophage and the amastigote.

Which parasite enzyme does trivalent antimony inhibit?

Trypanothione reductase, which keeps Leishmania's antioxidant defence working.

Which three organs or systems are watched during antimonial treatment?

The heart (ECG, QT), the pancreas (amylase and lipase) and the liver (transaminases), plus blood count and kidney function.

What is done for a pregnant woman with cutaneous leishmaniasis?

Antimonials are not given: thermotherapy is used or treatment is postponed; if urgent, liposomal amphotericin B.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: Lineamientos de atención clínica integral para Leishmaniasis en Colombia (Ministerio de Salud y Protección Social (Colombia), 2023); Clinical Care of Leishmaniasis (Centers for Disease Control and Prevention (CDC), 2024); Farmacología básica y clínica (Katzung), cap. 52 (McGraw Hill, 2025); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 67 (McGraw Hill, 2023).

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Representative model, for educational purposes only.