Psyllium
Psyllium is a bulk-forming agent derived from the ripe seeds of *Plantago* species. The seed coating is rich in hemicellulose mucilage, which absorbs water and swells significantly. **Key Veterinary Uses:** * **Horses:** Considered the laxative of choice for the treatment and prevention of sand colic. * **Small Animals:** Used as a laxative for constipation (especially when straining is deleterious or dietary fiber is too low) and to increase stool consistency in patients with chronic, watery diarrhea. **Clinical Pearls:** * When used for diarrhea, psyllium improves the *consistency* of the stool, but the total amount of water in the stool remains unchanged. * As a soluble fiber, it may undergo partial fermentation by colonic bacteria into short-chain fatty acids (SCFAs), which provide energy to colonocytes and support mucosal health.
Mecanismo: Psyllium acts primarily through mechanical and physical mechanisms in the gastrointestinal tract: * **Water Absorption:** The hemicellulose mucilage absorbs water in the intestinal lumen and swells. * **Peristalsis Induction:** The increased bulk distends the intestinal wall → stimulates stretch receptors → **induces peristalsis** and decreases overall intestinal transit time. * **Sand Clearance (Horses):** The mucilaginous gel formed by psyllium helps collect and bind sand, lubricating its passage through the GI tract for elimination.
Dosificación por especie
- Chronic constipation · 1-4 teaspoonsful per meal added to canned cat food · PO · per meal · Be sure cat is properly hydrated
- Adjunctive treatment of feline megacolon · 1-4 teaspoonsful mixed with food · PO · q12-24h
- Sand colic · 1 gram/kg · PO / NG tube · q12h · Mix approx 1 lb powder with water and administer immediately via NG tube. If giving orally to foals, give small amounts to prevent esophageal obstruction. Pelleted form is more palatable.
- Sand colic · 0.5 kg mixed with 1 liter of mash · PO · q12h · Given with 2 liters of mineral oil via NG tube once daily
- Sand impactions · 8 ounces in water · NG tube · q24h
- Trial to treat chronic idiopathic large bowel diarrhea · 2 tablespoonsful (1.33 grams/kg/day; range: 0.32-4.9 grams/kg/day) per day added to a highly digestible diet · PO · q24h · Using Metamucil
- To increase fiber in dogs with chronic colitis · 1-2 tablespoonsful (15-30 mL) per 25 kg body weight · PO · q24h · Add to animal's regular diet
- Predominantly large bowel diarrhea (therapeutic trial) · 0.5 tablespoon for toy breeds, 1 tablespoon for small dogs, 2 tablespoons for medium dogs, and 3 tablespoons for large dogs · PO · q24h · 5-10 days · Given alongside metronidazole 20-25 mg/kg PO twice daily
Vías de administración
Contraindicaciones
- Rabbits (may damage intestinal mucosa and cause blockage)
- Fecal impaction (no feces being passed)
- Intestinal obstruction
- Conditions where prompt intestinal evacuation is required
Efectos adversos
- Flatulence
- Esophageal obstruction (if administered with insufficient liquid)
- Bowel obstruction (if administered with insufficient liquid)
Interacciones farmacológicas
- Aspirin (and other salicylates) · Potential exists for psyllium to bind and reduce absorption if given at the same time; separate doses by 3 hours or more.
- Digoxin · Potential exists for psyllium to bind and reduce absorption if given at the same time; separate doses by 3 hours or more.
- Nitrofurantoin · Potential exists for psyllium to bind and reduce absorption if given at the same time; separate doses by 3 hours or more.
Monitorización
- Stool consistency
- Defecation frequency
- Hydration status
Sobredosis
If administered with sufficient liquid, psyllium overdose should cause only an increased amount of soft or loose stools. If administered without sufficient liquid, risk of severe esophageal or intestinal obstruction increases.
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