GASTRINE INJECTION

Metoclopramide 0.5%

Ranitidine 2%

VETERINARY USE

Gastrine Injection. Antacid. Gastrointestinal antiemetic and prokinetic.

Ready to use injectable sterile solution

Metoclopramide has effects at the gastrointestinal level and at the CNS level. Antagonizes the D2 and 5-HT3 dopamine receptors, producing a peripheral cholinergic effect. In the gastrointestinal tract, Metoclopramide stimulates the motility of the anterior portion, without effects on stomach, bile, and pancreatic secretions. It sensitizes the smooth muscle of the anterior region of the gastrointestinal tract to Acetylcholine. Increases the tone and amplitude of stomach contractions, relaxes the pylorus and increases duodenal and jejunal peristalsis. Gastric emptying and intestinal transit will be accelerated after the administration of this combination. It increases the pressure of the caudal sphincter of the esophagus and prevents gastric reflux, which is why metoclopramide has antiemetic and prokinetic effect.

After IM administration it has good absorption (Bd 74-96%). It is widely distributed in the body and crosses the blood – brain and placental barrier. It has low plasma protein binding (3 – 15%). It is metabolized at the liver level and is mainly eliminated in urine.

Ranitidine blocks histamine (H2) receptors located in gastric parietal cells. The H2 receptor is predominant in the stimulation of acid secretion. H2 receptor antagonists cause a 70-90% reduction in the production of gastric acid, by decreasing the amount of gastric juice secreted, the amount of secreted pepsin also decreases.

Ranitidine is widely distributed in the body and binds only 10 – 19 % to plasma proteins. It is excreted by the kidneys and metabolized in the liver where inactive metabolites are produced. Accumulation of this drug may occur in patients with renal impairment.

Bioactivity

Gastrine Injection has three therapeutic actions in a single solution, due to the combination of Metoclopramide as an antiemetic and prokinetic agent and the action of ranitidine as an antacid effective in dogs, cats and sport horses.

Its duration is 6 to 8 hours.

Indications

Dogs and Cats

Vomiting control associated with:

– Emetic disorders due to the stimulation of CTZ or depression of gastrointestinal motility.

– Oncological chemotherapy.

– Gastrointestinal reflux.

– Gastric ulcers.

– Gastric neoplasia.

– Postoperative gastric dilatation and surgery / intervention of the volvulus.

– Abnormal gastric motility

– Treatment and prevention of gastric ulceration syndrome caused by a variety of disorders, non-steroidal anti-inflammatory drugs (NSAIDs) and uremia.

– Immune mediated gastrointestinal inflammatory processes. Also indicated in reflux esophagitis, foreign bodies, caustics or chronic vomiting.

Sport Horses

– Increase post operative gastric emptying.

– Prevention of equine gastric ulceration syndrome

Routes of Administration

Apply IM, SC and IV.

Dosage

Dogs and Cats

Metoclopramide: 0.25 to 0.5 mg/kg every 6-8 hs IM-SC-IV

Ranitidine: 1.0-2.0 mg/kg every 6-8 hs IM-SC-IV

Equivalent to 0.5 to 1 mL every 10 kg of body weight

Active concentration (mg/mL)

Metoclopramide: 5 mg/mL

Ranitidine: 20 mg/mL

Sport Horses:

Metoclopramide: 0.04 mg/kg/h in continuos infusion EV

Ranitidine: 0.16 mg/kg/h in continuos infusion EV

Equivalent to 0.8 mL per 100 kg/h in continuos infusion.

Interactions:

Metoclopramide:

-The combination of metoclopramide and phenotiazines has excellent synergistic effects (due to their different modalities of action) in the management of persistent vomiting. However, due to the risk of potentiating the effects on CNS, Metoclopramide should be use with caution along with phenothiazines, butyrophenones and opioide analgesics.

– Anticholinergics and narcotics can nullify the effects of metoclopramide on gastrointestinal motility

– The gastrointestinal stimulation caused by metoclopramide can affect the absorption of numerous drugs. It can reduce the absorption of products that disintegrate, dissolve or absorb in the stomach, such as digoxin, although more enriched antral contractions can also accelerate disintegration.

– The predominant absorption of drugs in the small intestine, such as cimetidine, aspirin, tetracycline and diazepam may increase in the presence of metoclopramide.

Ranitidine:

• The increase in gastric pH associated with the administration of H2 antagonists may reduce the absorption of drugs that require an acidic medium for dissolution and absorption of drugs that require an acidic medium for dissolution and absorption, such as ketaconazole. It is recommended to administer it with citrus juices or avoid joint administration.
• Acetylsalicylic acid: Increasing the gastric pH increases serum levels of Acetylsalicylic acid, and then decreases the dose of aspirin.
• Nifedipine: increases its hypotensive effect.
• Paracetamol: increases serum levels enhancing its toxicity.
• Theophylline: joint administration causes theophylline inhibition.
• Vitamin B12: produces a decrease in the absorption of the vitamin, parenterally administered.
• Ranitidine only has minimal effects on the metabolism of other drugs at the renal level, not having clinical importance.
• Propanteline bromide delays absorption but increases the serum peak of Ranitidine. The bioavailability of ranitidine will be increased by 23% when both drugs are administered together.
• Antacids may decrease the absorption of Ranitidine, if used together, administer two hours apart between them.
• Ranitidine may decrease the renal clearence of procainamide, but the clinical importance of this drug is yet unknown.

Contraindications, Precautions and Use Limitations:

Metoclopramide:

It is contraindicated in patients with gastrointestinal bleeding, obstruction or perforation and in patients hypersensitive to the drug. In patients with pheochromocytoma the metoclopramide may induce hypertensive seizures.

In dogs the most common adverse effect (although rare) are changes in behavior (motor depression or hyperactivity with a tendency to depression)

Cats can show frantic changes in behavior or disorientation. Both species can suffer constipation in the period of administration of this drug.

In horses, IV administration of metoclopramide has been associated with severe central nervous effects, alternating periods of sedation and excitation, behavioral changes and abdominal pain. These effects are less common in foals.

Adverse effects are primarily related to the blockage of central dopaminergic receptors. Adverse effects similar to those known for phenothiazines (eg. acetylpromazine) were observed in addition to behavioral abnormalities. It is contraindicated in patient with seizure disorders. 

Ranitidine:

Patients hypersensitive to the drug. It should be used carefully and possibly reduce the dose in patients with decreased renal function.

The appearance of side effects at the recommended doses is very rare. Potential adverse effects that have appeared in humans and could arise in animals are mental confusion and headache. Rarely may occur agranulocytosis and if administered in an IV way, arrhythmias can occur quickly. Pain may occur at the place of application when is administered IM.

Intravenous bolus has been associated with vomiting in dogs and cats. It should be used with caution with vomiting dogs and cats.

Store between 15 and 30 ° C, protected from light, in a dry and hygienic place, out of the reach of children and domestic animals.

UNDER VETERINARY PRESCRIPTION ONLY