TOXICITY OF SULPHONAMIDE IN ANIMALS

TOXICITY OF SULPHONAMIDE IN ANIMALS

Dr. Mamta Meena^1* and Dr. Om Prakash Meena²

¹Assistant Professor Veterinary Pharmacology and Toxicology, Apollo college of Veterinary Medicine, Jaipur

²Assistant Professor Veterinary Medicine, Apollo college of Veterinary Medicine, Jaipur

Corresponding author: drmamtameena04@gmail.com

INTRODUCTION

• Sulphonamides are a group of synthetic organic chemical compound. It was first synthetic chemotherapeutic agent used for the treatment of acne and urinary tract infections in humans and animals.
• The antibacterial activity of sulphonamide was first discovered by Sir Gerhard Domagk in 1935 as prontosil, an azodye. It was found effective against streptococcal infection in mice and for it he got noble prize in 1938.
• Sulphonamide toxicity can occur through individual dosing or therapeutic application in feed or water.
• Most cases result from overdosing the animals or feeding sulphonamides to animals that have limited water supply or high fluid losses as a result of diarrhea.
• Sulphonamides are weak organic compounds, water insoluble, alkaline pH (about 9-10), strong irritant.
• Sulphonamides are found highly soluble in alkaline pH. In acidic urine they produce crystals because of low solubility and it leads to crystalluria and renal failure in animals.
• Combination of two different sulphonamides increases their solubility and decreases toxicity.
• The antibacterial action of sulphonamides is mainly due to inhibition of folic acid synthesis in susceptible bacteria due to their structural resemblance to para-aminobenzoic acid (PABA).
• Sulphonamides are bacteriostatic and broad spectrum antimicrobial drug. They are found active against Gm+ve and Gm-ve bacteria including Streptococcus pyogenes, Streptococcus pneumoniae, Haemophillus influenzae, Chlamydia, Pasteurella, Klebsiella, Clostridium spp.
• In cattle sulphonamides are more toxic due to extensive acetylation (metabolism), while in case of dogs acetylation is absent so no or less toxicity.
• In dogs sulphonamides are metabolized by glucuronidation.
• Most important side effects are found on kidney.

Acute toxicity

• Renal toxicity– The renal toxicity of sulphonamides is attributable to their precipitation in the glomerular filtrate leading to crystalluria, haematuria and obstruction of renal tubule, ureter and bladder. Renal toxicity is found highly in dehydrated animals, acidic urine like carnivores and omnivores. Not or less in herbivores. It can be minimised by adequate water supply and by administration of Triple sulpha (Sulphapyridine + Sulphamerazine + Sulphadiazine). And by using urinary alkalizers like sodium bicarbonate in dogs and cats.
• Blood dyscriasis– Haemolytic anaemia by glucose-6-phosphate dehydrogenase defficiency (within 2-7 days of therapy). Neutropenia occur.
• Hypersensitivity reactions– allergic skin rashes, dermatitis. Sulphadiazine in Doberman breed produces polyarthritis.

Chronic toxicity

• Hypoprothrombinaemia– prolonged sulpha administration leads to Vit K deficiency (due to inhibition of enzyme Vit k epoxide reductase). Prolong bleeding and clotting time. Mainly in poultry due to sulphaquinoxaline.
• Keratoconjunctivitis sicca– dry eye in dogs.

• Inhibition of carbonic anhydrous enzyme– it leads to acumulation of CO2 and acidosis.
• Hepatic necrosis– in dogs.
• Aplastic anaemia and Thrombocytopaenia– Bone marrow suppression.

• Clinical uses- for the treatment of various systemic and local infections.

Sulphadiazine

• Prototype drug. Used with Trimethoprim. To treat Toxoplasma gondii Dog/Cat- 50-100mg/kg PO, Cattle 100mg/kg IV.

Sulphadimidine

• Cattle and sheep- 200mg/kg SC and IV

Mafenide and Silver Sulphadiazine

• Effective in pus. Used to treat burn.
• Sulfones or Dapsone- Mycobacterium laprae. To treat leprosy in man.

POTENTIATED SULPHONAMIDES

• Used in 1:5 ratio– 1 part of Trimethoprim and 5 parts of sulpha drug
• Co-Trimoxazoleà Trimethoprim + Sulphamethoxazole
• Co-Trimazine à Trimethoprim + Sulphadiazine
• Trimethoprim + Sulphadoxine
• Ormetoprim + Sulphadimethoxine
• Baquiloprim + Sulhadimethoxine
• Baquiloprim + Sulphadimidine
• https://www.pashudhanpraharee.com/laboratory-diagnosis-of-canine-and-feline-diseases/

 https://www.msdvetmanual.com/pharmacology/antibacterial-agents/sulfonamides-and-sulfonamide-combinations

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