Etiology and Clinical Forms of Leishmaniasis
The disease is transmitted through the bites of sandflies of the genus Phlebotomus. Depending on the causative species and clinical presentation, two main forms are distinguished:
- Visceral leishmaniasis (Kala-azar): caused by Leishmania donovani. This is a systemic pathology affecting the reticuloendothelial system, primarily the liver and spleen.
- Cutaneous leishmaniasis: caused by Leishmania tropica, L. braziliensis, and L. mexicana. The disease manifests as cutaneous nodules progressing to chronic ulcers (also known as Oriental sore or Baghdad boil). The infection can spread along lymphatic vessels.
Antimony Compounds and Mechanism of Action
The mainstay of etiotropic therapy consists of drugs containing pentavalent antimony. These include sodium stibogluconate, meglumine antimoniate, and solasulfone/solusurmine.
The exact mechanism of the antiprotozoal action is not fully understood, but key processes include:
- Inhibition of the parasite's intermediary metabolism, including glycolysis and fatty acid oxidation.
- Nonspecific interaction with and modification of sulfhydryl groups in the pathogen's protein structures.
Toxicity and Adverse Effects
Therapy with antimony compounds is associated with the risk of serious adverse reactions affecting various organ systems:
- Hematotoxicity: bone marrow suppression.
- Cardiotoxicity: characteristic prolongation of the Q-T interval on ECG.
- Organ damage: development of pancreatitis.
- Allergy: skin rashes.
Solusurmine
Solusurmine is a complex compound of pentavalent antimony with gluconic acid, where the active element content is 21–23%. Structurally, it is close to sodium stibogluconate.
- Indications: prescribed for cutaneous and visceral leishmaniasis.
- Contraindications: acute infectious processes, severe malnutrition, and intoxication.
- Clinical nuance: in severe visceral forms, the drug is used for life-saving indications, completely overriding standard contraindications.