Ranitidine is a drug that inhibits gastric acid secretion in cats because it binds to the histamine H2 receptors in the stomach, responsible for the release of said acid. For this reason, it is an active ingredient used in processes related to stomach acids, such as gastritis, esophagitis, gastroesophageal reflux and gastric ulcers. Not only that, ranitidine also has prokinetic effects, so it promotes digestive transit and has a protective effect on the gastrointestinal mucosa, which is important when certain drugs are used.
What is ranitidine?
Ranitidine is an active substance or drug that belongs to the group of H2 antagonists H2 receptors are one of two types of histamine receptors. Histamine is, without a doubt, the greatest paracrine stimulant of gastric acids, releasing said acid after binding to H2 receptors. Histamine is present in the mast cells of the stomach and is released by the action of gastrin. In this way, ranitidine binds to H2 receptors and prevents the binding of histamine, limiting gastric acid secretion
Because it produces a reduction in the secretion of stomach acids, it prevents and treats peptidic ulcers, gastroesophageal reflux, inflammation of the esophagus or esophagitis and inflammation of the stomach or gastritis in cats. In addition, ranitidine can accelerate the emptying of the gastrointestinal tract due to its inhibitory effect on acetylcholinesterase, which produces an increase in acetylcholine and has a protective and healing effect on the digestive mucosa, serving as protection from the irritating action of non-steroidal anti-inflammatory drugs (NSAIDs).
Ranitidine binds poorly to plasma proteins, crosses the blood-brain barrier or blood-brain barrier, being found at good levels in the cerebrospinal fluid and also passes into breast milk. The effect of inhibition of stomach secretion lasts for hours, so daily administration is required, metabolism is hepatic and elimination is renal.
What is ranitidine used for in cats?
As discussed, ranitidine is used for gastritis, esophagitis, and to increase gastrointestinal movement of food in cats due to its ability to block histamine in the stomach, essential in the secretion of gastric acid, this being responsible for the appearance of these pathologies in these animals.
Because ranitidine blocks the release of histamine in the stomach and inhibits the production of stomach acid, it reduces the potential for ulcer formation by making the environment in the stomach more alkaline.
Another common use of ranitidine in cats is to treat nausea that occurs in cats after the use of certain medications, intoxications, excess acid or suffering from chronic diseases such as kidney disease, liver disorders, cancer, pancreatitis and irritable bowel syndrome. Signs that a cat is nauseated are lip smacking, anorexia, food refusal, drooling, vomiting, and constant swallowing.
Dosage Ranitidine for Cats
The dose of ranitidine in cats is 2 to 4 mg per kg of body weight per day Administration can be via oral, parenteral or intravenous. Depending on the form of the drug, the weight of the cat and the concentration of ranitidine in the product, the dosage will vary.
Never give ranitidine to your cat without first having veterinary advice and prescription, only this professional is the one who can define the exact ideal dose for your cat according to the condition it presents and its needs. Keep in mind that it may take several days to see the full effect of improving signs such as nausea, reflux and anorexia.
Side Effects of Ranitidine for Cats
Ranitidine does not usually cause side effects in cats. However, it should be noted that some unwanted effects may occur with ranitidine treatment, such as the following:
- Rebound effect with hypersecretion of gastric acid after withdrawal of ranitidine treatment.
- Increase in plasma gastrin concentration.
- Drug accumulation in patients with kidney or liver disease.
- Vomiting.
- Irregular heartbeat.
- Rapid breathing (tachypnea).
- Diarrhea.
- Muscle tremors.
Contraindications of ranitidine for cats
It must be taken into account that in cases of overdose of ranitidine, an increase in hepatic ALT (alanine aminotransferase enzyme) may be observed. In addition, ranitidine has a number of contraindications in cats.
To begin with, ranitidine should not be used if the cat is on treatment with itraconazole or ketoconazolebecause these drugs require an acidic environment for their oral absorption as they are weak bases, so treatment with ranitidine reduces the effect of these drugs by reducing their bioavailability. In case an antifungal treatment is required with the use of ranitidine, it is better to opt, if possible, for another antifungal such as fluconazole, whose absorption does not depend on the pH of the stomach. It should also not be used with some oral cephalosporins because ranitidine may affect their pharmacokinetics.
Ranitidine should not be used in pregnant females in the last days of pregnancy and is not indicated incats are liver or kidney diseases , requiring the use of a lower dose. In lactating females ranitidine should not be used either, since it passes into the milk and kittens can also suppress their gastric secretion at the same time that nervous signs appear due to stimulation of the central nervous system and inhibit the metabolism of other drugs.
Caution in the use of ranitidine in cats
It should be noted that, at the beginning of February 2022, the Spanish Agency for Medicines and He alth Products (AEMPS)[1] has established the recommendation of not to use either magisterial formulations containing ranitidine or prescribe ranitidine in any medication due to the risk of presenting the impurity N-Nitrosodimethylamine (NDMA), also known as nitrosamine, at levels higher than those established, being a potential carcinogen.
This was observed in 2019, allowing its use in the form of intravenous administration as it is the only H2 inhibitor marketed in this form of presentation, and being indicated for some therapeutic needs in certain patients while batches were checked for this compound. The following year, by means of a Commission Decision, all national authorizations for the oral product were suspended in Spain for having found this compound at levels higher than those established in different batches of the active ingredient, but not so with those of intravenous use, being able to postpone its suspension until November 25, 2021. However, when this date arrived, nothing could prevent its suspension, so as of today no medication with ranitidine should be prescribed either for oral or parenteral in human medicine or in veterinary medicine, other H2 receptor inhibitors such as famotidine or cimetidine should be used.
