Sodium Iodide / Potassium Iodide
Iodides (Sodium Iodide and Potassium Iodide) are primarily utilized in veterinary medicine for their effects against specific granulomatous infections. Key indications include: * **Actinobacillosis** (woody tongue) and **Actinomycosis** (lumpy jaw) in cattle and other ruminants. * **Sporotrichosis** (a deep fungal infection) in horses, dogs, and cats. * Occasionally used as an **expectorant** or as a supplement for **iodine deficiency** disorders. > **Clinical Pearl:** Use in cats is controversial as they are highly susceptible to iodide toxicity (iodism). Alternative antifungal therapies like itraconazole are often preferred for feline sporotrichosis.
Mechanism: The exact mechanism of action for treating actinobacillosis and sporotrichosis is unknown. * Iodides possess little to no direct *in vitro* antimicrobial or antifungal activity. * They are believed to act by modifying the **granulomatous inflammatory process**. * **Proposed mechanism:** Iodides may enhance **phagocytosis** by macrophages or alter the immune response within granulomas, facilitating the breakdown of granulomatous tissue and allowing the body's immune system to clear the infection.
Dosing by species
- Actinobacillosis ยท 70 mg/kg IV given as a 10% or 20% solution ยท IV ยท repeat at least one more time at a 7-10 day interval ยท Refractory cases may require more frequent (2-3 day intervals) treatment.
- Actinobacillosis ยท 70 mg/kg IV given as a 10% or 20% solution ยท IV ยท repeat at least one more time at a 7-10 day interval ยท Refractory cases may require more frequent (2-3 day intervals) treatment.
- Sporotrichosis ยท 20 mg/kg PO q12-24h ยท PO ยท q12-24h ยท at least 60 days
- Sporotrichosis ยท 20 mg/kg PO q12-24h ยท PO ยท q12-24h ยท Using SSKI; give with food. Itraconazole is less likely to cause adverse effects.
- Actinobacillosis (woody tongue) ยท 70 mg/kg IV given as a 10% or 20% solution ยท IV ยท repeat at least one more time at a 7-10 day interval ยท Refractory cases may require more frequent (2-3 day intervals) treatment. Severe cases may require adjunctive antibiotics.
- Sporotrichosis ยท 20-40 mg/kg PO daily ยท PO ยท q24h ยท several weeks ยท Sodium iodide
- Sporotrichosis ยท Loading dose of sodium iodide at 20-40 mg/kg IV for 2-5 days, then 20-40 mg/kg PO once daily ยท IV, PO ยท q24h ยท at least 3 weeks after all clinical lesions disappear ยท May administer via oral syringe or mixed in sweet feed. Topical hot packs of 20% sodium iodide may be used on open wounds.
Routes of administration
Contraindications
- Known iodide hypersensitivity
- Lactating animals (excreted in milk)
- Hyperthyroidism
- Renal failure
- Severe dehydration
- Pregnancy (may cause abortion in cattle)
Adverse effects
- Excessive tearing (epiphora)
- Vomiting and nausea
- Anorexia / inappetence
- Nasal discharge
- Muscle twitching
- Cardiomyopathy
- Scaly haircoats and dandruff
- Hyperthermia
- Decreased milk production
- Decreased weight gain
- Coughing
- Diarrhea
- Goiter (especially in foals from supplemented mares)
- Cardiovascular failure (in severe toxicity)
Drug interactions
- Antithyroid medications ยท Iodides may decrease the efficacy of antithyroid medications.
- Thyroid supplements ยท Iodides may enhance the efficacy of thyroid medications.
Monitoring
- Clinical efficacy (resolution of granulomatous lesions)
- Signs of iodism (excessive tearing, nasal discharge, scaly haircoats/dandruff, hyperthermia, coughing, diarrhea)
- Thyroid function (if used long-term)
Overdose
Excessive iodine accumulation leads to a toxic syndrome known as **iodism**. * **Clinical Signs:** Excessive tearing (epiphora), vomiting, anorexia, nasal discharge, muscle twitching, cardiomyopathy, scaly haircoats/dandruff, hyperthermia, decreased milk production and weight gain, coughing, inappetence, and diarrhea. * **Species Sensitivity:** Cats are particularly prone to developing iodism. Young animals may be more susceptible than adults. Foals have developed goiter when mares were excessively supplemented. * **Severe Toxicity:** Can progress to depression, hypothermia, and cardiovascular failure.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerโs current label.