Sulfachlorpyridazine Sodium
Sulfachlorpyridazine sodium is a short- to intermediate-acting, low lipid-soluble sulfonamide antimicrobial agent. In veterinary medicine, it is primarily indicated for the treatment of enteric infections, particularly diarrhea caused or complicated by **E. coli** in calves (under one month of age) and colibacillosis in swine. It is also utilized parenterally as a general-purpose sulfonamide in adult cattle and other species. **Clinical Pearls:** * As a **time-dependent, bacteriostatic** antibiotic, maintaining consistent dosing intervals is crucial for efficacy. * While resistance to sulfonamides is an increasing and widespread phenomenon, sulfachlorpyridazine remains a valuable tool for specific herd health applications. * It is highly soluble in urine at usual physiological pH levels, though crystalluria remains a risk in dehydrated patients or those with highly concentrated, acidic urine.
Mecanismo: Sulfonamides are generally bacteriostatic agents. They act as structural analogues of para-aminobenzoic acid (PABA). * They competitively inhibit the bacterial enzyme **dihydropteroate synthase**. * This blocks the incorporation of PABA into **dihydropteroic acid** → preventing the biosynthesis of **tetrahydrofolic acid** (the active form of folic acid). * Because mammalian cells utilize preformed dietary folic acid and do not synthesize their own, they are generally unaffected by this mechanism. * Efficacy is significantly reduced in the presence of pus, necrotic tissue, or extensive cellular debris, as these environments are rich in PABA which outcompetes the drug.
Dosificación por especie
- Diarrhea caused or complicated by E. coli in calves less than one month of age · 33-49.5 mg/kg PO, or IV twice daily · PO/IV · q12h · 1-5 days · Suggest initiating therapy with intravenous preparation and then changing to oral if possible
- Enteric bacterial infections (E. coli) · Mix 1/4 teaspoonful per liter of water and use as only supply of drinking water · PO · continuous · 5-10 days · Using the oral powder. May be effective for many E. coli enteric infections.
- Enteric bacterial infections (E. coli) · Mix 3/4 teaspoonsful per 2 quarts of water · PO · continuous · Using the oral powder. Fairly effective for enteric infections, particularly E. coli. Reserved for clients who are unable to give other medications by mouth or parenterally.
- E. coli and coccidiosis in pigeons · 1200 mg per gallon of drinking water · PO · continuous · Very effective for E. coli and it is a good coccidiostat.
- Colibacillosis · 44-77 mg/kg PO per day (divide dose and give twice daily if treating individual animals) · PO · q12h or q24h · 1-5 days
Las dosis son una referencia clínica para médicos veterinarios. Confirme siempre con la información vigente del producto y el paciente individual.
Vías de administración
Contraindicaciones
- Hypersensitivity to sulfonamides, thiazides, or sulfonylurea agents
- Severe renal impairment
- Severe hepatic impairment
Efectos adversos
- Crystalluria
- Hematuria
- Renal tubule obstruction
- Keratoconjunctivitis sicca (KCS) in dogs
- Bone marrow depression
- Hypersensitivity reactions (rashes, dermatitis)
- Focal retinitis
- Fever
- Vomiting
- Nonseptic polyarthritis
- Muscle weakness, blindness, ataxia, and collapse (with rapid IV injection)
- Tissue irritation and necrosis (with IM or SC injection)
- Temporary depression of normal cellulytic function in the ruminoreticulum
Interacciones farmacológicas
- Antacids · May decrease the oral bioavailability of sulfonamides if administered concurrently
Monitoreo
- Clinical efficacy (resolution of diarrhea/infection)
- Adverse effects
- Hydration status and urine output
Sobredosis
Acute toxicity secondary to overdoses apparently occurs only rarely in veterinary species. * **Signs of Toxicity:** In addition to standard adverse effects, **CNS stimulation** and **myelin degeneration** have been noted after very high dosages. * **Treatment:** Treatment is largely supportive and symptomatic. Ensure aggressive fluid therapy to maintain urine output and prevent crystalluria.
La referencia de fármacos de VetSheet está destinada a médicos veterinarios como apoyo a la decisión clínica; no sustituye el juicio profesional ni la información vigente del fabricante.