Changes

===Histamine 2 receptor antagonists===

===Histamine 2 receptor antagonists===

This concept follows from the still widely held belief, ‘no acid, no ulcer’ (Fig 19). The current treatment of choice is to suppress acid production from the parietal cells. These cells release acid when any one of 3 distinct receptors (histamine, acetylcholine, gastrin) is stimulated. Currently, the most popular treatment involves an histamine receptor antagonist (H2 blocker). The proton-pump inhibitors constitute a new treatment approach that blocks acid production within the cell. This modality is receptor-independent and therefore more effective.(EGUC)

Parietal cells secrete HCl upon stimulation of histamine, acetylcholine or gastrin receptors.(EGUC) Competitive H2 receptor antagonists have successfully elevated gastric pH and treated gastric ulcers in mature horses and foals.(44,85,97 in Sachez)

 

The 4 most popular Hz antagonists licensed in the United States for man are cimetidine, ranitidine, famotidine and nizatidine. Cimetidine has been shown to affect hepatic disposition of some drugs.

Currently recommended doses proposed to be effective in the majority of horses(Sanchez) are:

*'''Cimetidine''' 20-30mg/kg PO every 8 hours or 6.6mg/kg IV every 6 hours

The problem with treatment of gastric ulcers in horses is that individuals have different dose requirements for effective treatment. This probably relates to varying bioavailability of the drug in individual horses. The bioavailability of H2 antagonists is generally lower in horses than in man. The wide variability among horses in acid suppression achieved with H2 antagonists may be a result of other unknown factors as well; this variability is most pronounced at low doses. The medication selected, dosage and duration of treatment depend on the location and severity of lesions, clinical signs, and owner considerations.,

 

The proton-pump inhibitors constitute a new treatment approach that blocks acid production within the cell. This modality is receptor-independent and therefore more effective.(EGUC)

 

 

Cimetidine has been shown to affect hepatic disposition of some drugs.

 

The problem with treatment of gastric ulcers in horses is that individuals have different dose requirements for effective treatment. This probably relates to varying bioavailability of the drug in individual horses. The wide variability among horses in acid suppression achieved with H2 antagonists

===Proton-pump inhibitors===

===Proton-pump inhibitors===