Definition
Sulfaguanidine is a synthetic sulfonamide antibacterial agent that contains a guanidine functional group. It is primarily employed in veterinary medicine as a feed additive for the control of enteric bacterial infections, especially those caused by Escherichia coli in swine.
Overview
Developed in the mid‑20th century as part of the sulfonamide class of antimicrobials, sulfaguanidine is characterized by very low systemic absorption after oral administration, which limits its activity to the gastrointestinal tract. This pharmacokinetic profile makes it suitable for targeting intestinal pathogens while minimizing exposure of the host’s systemic flora. Clinical use has been largely confined to the prophylaxis and treatment of colibacillosis in piglets and, in some jurisdictions, to other livestock species. Because of concerns about antimicrobial resistance and the availability of newer agents, its use has declined in many countries and is subject to regulatory restrictions.
Etymology/Origin
The term “sulfaguanidine” combines “sulfa,” referring to the sulfonamide (–SO₂NH–) moiety that is the hallmark of sulfonamide antibiotics, with “guanidine,” indicating the presence of a guanidine functional group (–C(=NH)NH₂). The name thus directly reflects the compound’s chemical structure.
Characteristics
| Property | Description |
|---|---|
| Chemical class | Sulfonamide (aryl‑sulfonamide) containing a guanidine substituent |
| Molecular formula | C₉H₁₂N₄O₂S (reported in several chemical databases) |
| Molecular weight | Approximately 236 g·mol⁻¹ |
| Physical form | White to off‑white crystalline solid |
| Solubility | Sparingly soluble in water; solubility increases in acidic media |
| Stability | Stable under normal storage conditions; sensitive to strong bases |
| Pharmacokinetics | Oral bioavailability < 1 % in most species; acts locally in the gut |
| Mechanism of action | Competitive inhibition of bacterial dihydropteroate synthase, thereby blocking folic‑acid synthesis |
| Spectrum of activity | Primarily effective against Gram‑negative enteric bacteria, notably E. coli; limited activity against Gram‑positive organisms |
| Regulatory status | Approved for veterinary use in several jurisdictions; withdrawn or restricted in others due to resistance concerns |
Related Topics
- Sulfonamide antibiotics – the broader class of antibacterial agents that inhibit folic‑acid synthesis.
- Guanidine derivatives – compounds containing the guanidine functional group, many of which have antimicrobial or antiseptic properties.
- Colibacillosis – a common bacterial diarrheal disease in piglets caused by pathogenic E. coli.
- Antimicrobial resistance (AMR) – the increasing prevalence of resistant bacterial strains that has prompted tighter regulation of older sulfonamides like sulfaguanidine.
- Veterinary pharmacology – the study of drug action, disposition, and therapeutic use in animal species, where sulfaguanidine has historically been employed.
Note: The information presented reflects the current consensus in scientific literature and regulatory documents as of 2026. No speculative or unverified statements are included.