- Improves and heals gastric ulcers
- Prevents gastric ulcer recurrences
- Once-a-day dosing
The incidence of gastric ulcers in performance horses is high (up to 90%). Clinical signs of gastric ulcers include inappetence or
decreased appetite, recurrent colic, intermittent loose stools or
chronic diarrhea, poor hair coat, poor body condition, or poor
performance.
Dosage
Regimen
For treatment of
gastric ulcers, GASTROGARD Paste should be
administered orally once-a-day for 4 weeks at the recommended dosage of
1.8 mg omeprazole/lb body weight (4 mg/kg). For the prevention of
recurrence of ulcers, continue treatment for at least an additional 4
weeks by administering GASTROGARD Paste at the
recommended daily maintenance dose of 0.9 mg/lb (2 mg/kg).
Directions for Use
GASTROGARD Paste for horses is recommended for use in horses and
foals 4 weeks of age and older. The contents of one syringe will dose a
1250 lb (568 kg) horse at the rate of 1.8 mg omeprazole/lb body weight
(4 mg/kg). For treatment of gastric ulcers, each weight marking on the
syringe plunger will deliver sufficient omeprazole to treat 250 lb (114
kg) body weight. For prevention of recurrence of gastric ulcers, each
weight marking will deliver sufficient omeprazole to dose 500 lb (227
kg) body weight.
Treatment: To deliver
GASTROGARD Paste at the treatment dose rate of
1.8 mg omeprazole/lb body weight (4 mg/kg), set the syringe plunger to
the appropriate weight marking according to the horse's weight in
pounds.
Prevention: To deliver
GASTROGARD Paste at the dose rate of 0.9 mg/lb
(2 mg/kg) to prevent recurrence of ulcers, set the syringe plunger to
the weight marking corresponding to half of the horse's weight in
pounds.
To set the syringe
plunger, unlock the knurled ring by rotating it 1/4 turn. Slide the
knurled ring along the plunger shaft so that the side nearest the barrel
is at the appropriate notch. Rotate the plunger ring 1/4 turn to lock it
in place and ensure it is locked. Make sure the horse's mouth contains
no feed. Remove the cover from the tip of the syringe, and insert the
syringe into the horse's mouth at the interdental space. Depress the
plunger until stopped by the knurled ring. The dose should be deposited
on the back of the tongue or deep into the cheek pouch. Care should be
taken to ensure that the horse consumes the complete dose. Treated
animals should be observed briefly after administration to ensure that
part of the dose is not lost or rejected. If any of the dose is lost,
redosing is recommended.
If, after dosing, the
syringe is not completely empty, it may be reused on following days
until emptied. Replace the cap after each use.
Federal (USA) law restricts
this drug to use by or on the order of a licensed veterinarian
Warning
Do not use
in horses intended for human consumption. Keep this and all drugs
out of the reach of children. In case of ingestion, contact a physician.
Physicians may contact a poison control center for advice concerning
accidental ingestion.
Adverse
Reactions
In efficacy trials, when
the drug was administered at 1.8 mg omeprazole/lb (4 mg/kg) body weight
daily for 28 days and 0.9 mg omeprazole/lb (2 mg/kg) body weight daily
for 30 additional days, no adverse reactions were observed.
Precautions
The safety of
GASTROGARD Paste has not been determined in
pregnant or lactating mares.
Clinical
Pharmacology
Mechanism
of Action: Omeprazole is a gastric acid pump inhibitor that
regulates the final step in hydrogen ion production and blocks gastric
acid secretion regardless of the stimulus. Omeprazole irreversibly binds
to the gastric parietal cell's H+, K+ ATPase enzyme which pumps hydrogen
ions into the lumen of the stomach in exchange for potassium ions. Since
omeprazole accumulates in the cell cannaliculi and is irreversibly bound
to the effect site, the plasma concentration at steady state is not
directly related to the amount that is bound to the enzyme. The
relationship between omeprazole action and plasma concentration is a
function of the rate-limiting process of H+, K+ ATPase
activity/turnover. Once all of the enzyme becomes bound, acid secretion
resumes only after new H+, K+ ATPase is synthesized in the parietal cell
(i.e., the rate of new enzyme synthesis exceeds the rate of inhibition).
Diagnostic
and Management Considerations: The following clinical signs may be
associated with gastric ulceration in adult horses: inappetence or
decreased appetite, recurrent colic, intermittent loose stools or
chronic diarrhea, poor hair coat, poor body condition, or poor
performance. Clinical signs in foals may include: bruxism (grinding of
teeth), excess salivation, colic, cranial abdominal tenderness,
anorexia, diarrhea, sternal recumbency or weakness. A more accurate
diagnosis of gastric ulceration in horses and foals may be made if
ulcers are visualized directly by endoscopic examination of the gastric
mucosa.
Gastric ulcers may recur
in horses if therapy to prevent recurrence is not administered after the
initial treatment is completed. Use GASTROGARD
Paste at 0.9 mg omeprazole/lb body weight (2 mg/kg) for control of
gastric ulcers following treatment. The safety of administration of
GASTROGARD Paste for longer than 91 days has
not been determined.
Maximal acid suppression
occurs after three to five days of treatment with omeprazole.
Safety
GASTROGARD Paste was well tolerated in the following controlled
efficacy and safety studies.
In field trials involving
139 horses, including foals as young as one month of age, no adverse
reactions attributable to omeprazole treatment were noted.
In a placebo controlled
adult horse safety study, horses received 20 mg/kg/day omeprazole (5x
the recommended dose) for 90 days. No treatment related adverse effects
were observed.
In a placebo controlled
tolerance study, adult horses were treated with
GASTROGARD Paste at a dosage of 40 mg/kg/day (10x the recommended
dose) for 21 days. No treatment related adverse effects were observed.
A placebo controlled foal
safety study evaluated the safety of omeprazole at doses of 4, 12 or 20
mg/kg (1, 3, or 5x) once daily for 91 days. Foals ranged in age from 66
to 110 days at study initiation. Gamma glutamyltransferase (GGT) levels
were significantly elevated in horses treated at exaggerated doses of 20
mg/kg (5x the recommended dose). Mean stomach to body weight ratio was
higher for foals in the 3x and 5x groups than for controls; however, no
abnormalities of the stomach were evident on histological examination.
Reproductive Safety
In a male reproductive
safety study, 10 stallions received GASTROGARD
Paste at 12 mg/kg/day (3x the recommended dose) for 70 days. No
treatment related adverse effects on semen quality or breeding behavior
were observed. A safety study in breeding mares has not been conducted.
How
Supplied
GASTROGARD (omeprazole) Paste for
horses contains 37% w/w omeprazole and is available in an
adjustable-dose syringe. Each syringe contains 2.28 g of omeprazole.
Syringes are calibrated according to body weight and are available in
boxes of 7 units or 72 units.
Ulcergard, also
from Merial, is the non-prescription alternative to Gastrogard. The
Ulcergard syringe has the same amount and the same concentration of
Omeprazole as the Gastrogard syringe. The only difference is the
label and directions with Ulcergard being used as a preventative (1/4
syringe per dose) rather than as a treatment (a full syringe per dose).
Storage
Conditions
Store at 68°F - 77°
(20-25°C). Excursions between 59°F - 86°F (15-30°C) are permitted.
Merial
