generality
What are cytoprotective drugs?
Cytoprotectors are drugs capable of exerting aprotective action against the gastric mucosa.
For this reason, these drugs are widely used in the treatment of gastritis, reflux esophagitis and ulcers. It is not surprising, therefore, that they are to all intents and purposes the group of gods gastroprotectors and anti-ulcer medications.
Cytoprotective drugs can be divided into:
- Protective agents of the mucous membranes such as sucralfate and colloidal bismuth;
- Prostaglandin analogs such as misoprostol.
The main characteristics of these active ingredients will be briefly described below.
Sucralfato
What is that?
From a chemical point of view, sucralfate is a complex of sucrose octasulfate e aluminum hydroxide (chemical formula Al (OH) ₃).
How does it work?
The cytoprotective action of sucralfate is exerted through the formation of a very thick gel that you stratifies at the level of the gastroduodenal mucosa. In particular, in the presence of ulcers, sucralfate establishes selective bonds with the proteins present in the ulcerative crater giving rise to a real protective barrier against the further aggression of gastric acids.
At the same time, sucralfate is capable of:
- Stimulate the production of mucus and bicarbonates;
- Stimulate the synthesis of prostaglandins also with cytoprotective action;
- Inhibit the activity of pepsin.
How and when is it taken?
Sucralfate should be administered orally, on an empty stomach, one hour before meals and in the evening before bedtime. The posology may vary according to the medicine considered; therefore, it is recommended that you follow your doctor's instructions and the instructions on the package insert.
We also remind you that sucralfate is able to alter the absorption of some types of drugs; therefore, its intake should take place away from taking these drugs (for more information, read the package leaflet of the medicine containing sucralfate that you must take and / or ask your doctor or pharmacist for advice).
Use in Pregnancy and Lactation
There are no data on the safety of use of sucralfate in pregnant women and breastfeeding mothers; therefore, the possibility of using this cytoprotective drug or not will have to be carefully evaluated by the doctor. However, in general, its use during gestation is not recommended.
Undesirable Effects of Sucralfate
Among the main undesirable effects, we find:
- Constipation;
- Gastrointestinal disturbances, such as flatulence, nausea, vomiting;
- Rash;
- Itching;
- Insomnia;
- Dizziness;
- Headache.
Furthermore, the possible onset of allergic reactions should not be forgotten.
When NOT to use Sucralfate
The main contraindication to the use of sucralfate concerns the presence of allergy note to the same active ingredient and / or to one or more of the excipients contained in the medicinal product that contains it and to be taken. In addition, sucralfate should NOT be used in moles premature babies and its use results generally contraindicated in pregnancy.
Colloidal Bismuth and Subcitrate
What it is and main features
Colloidal bismuth is another active ingredient capable of exercising a cytoprotective action, stimulating the synthesis of prostaglandins and that of bicarbonates. However, it is not used in this sense.
In fact, bismuth has been shown to be toxic towards Helicobacter pylori, a microorganism known to favor the appearance of gastric and duodenal ulcers and to be one of the risk factors that can contribute to the onset of stomach tumors. For this reason, this element (in the form of bismuth subcitrate potassium) is used in combination with antibiotic drugs (metronidazole and tetracycline) in the eradication therapy of H. pylori.
The mechanism of action through which bismuth carries out its toxic action against this microorganism is not entirely clear, but it seems that it may be related to a direct toxicity on the functionality of the H. pylori membrane, to the inhibition of synthesis protein and cellular, inhibition of urease enzyme activity, prevention of cytoadherence, prevention of ATP synthesis and non-specific competitive interference with iron transport.
Currently (June 2021), only one authorized medicinal product is available in the country containing the combination of bismuth subcitrate potassium, metronidazole and tetracycline whose trade name is Pylera®.
For further information: Pylera® - Package LeafletMisoprostolo
What is that?
Misoprostol belongs to the group of prostaglandin analogues. More precisely, it is a synthetic analogue of prostaglandin E1 (PGE1). At the gastric level, misoprostol exerts a cytoprotective action, for this reason, its use is indicated precisely for the prevention and treatment of lesions of the gastrointestinal mucosa and gastroduodenal ulcers, in particular, induced by the administration of NSAIDs (anti-inflammatory drugs not steroids).
How does it work?
The cytoprotective action exerted by misoprostol is due to its ability to:
- Stimulate mucus secretion;
- Stimulate the secretion of bicarbonates;
- Inhibit the secretion of pepsin;
- Inhibit the secretion of gastric acid.
How and when is it taken?
In order for misoprostol to exert its cytoprotective action, it must be taken orally, preferably with meals. To prevent lesions of the gastrointestinal mucosa, the recommended dose is usually 200 mcg 2-4 times a day; while to treat them, the dose can be increased up to 800 mcg per day to be taken in 2-4 divided doses. However, always follow the directions given by your doctor and the instructions on the misoprostol medicine you are taking.
Use in Pregnancy and Lactation
Due to the inducing activity of childbirth and the abortive action that misoprostol can induce, its use to prevent and treat lesions of the gastrointestinal mucosa is contraindicated during pregnancy. Since the active ingredient is excreted in breast milk, the 'use during breastfeeding must be avoided.
Undesirable Effects of Sucralfate
Among the main undesirable effects caused by misoprostol when used as a cytoprotective drug, we find:
- Abdominal pain
- Nausea and vomit;
- Diarrhea or constipation
- Dizziness
- Headache;
- Uterine cramps, intermenstrual bleeding, menorrhagia, dysmenorrhea.
Not to forget, then, the possible onset of allergic reactions in sensitive individuals.
When NOT to use Misoprostol
The use of misoprostol is contraindicated in case of:
- Allergy known to the same active ingredient and / or to one or more of the other components of the medicine containing misoprostol that you have to take;
- Pregnancy;
- Breastfeeding.
Other Barrier-Forming Drugs
We conclude the article by recalling other active ingredients capable of forming a barrier in the stomach but which are not properly included in the group of cytoprotective drugs:alginic acid and sodium alginate. They are generally found in association with antacid drugs, such as sodium bicarbonate. They are used in particular in the treatment of stomach ache and symptoms of gastroesophageal reflux.
Following their ingestion, these active ingredients interact with the hydrochloric acid present in the stomach forming a almost neutral pH alginic acid gel barrier which - floating on the surface of the gastric contents - is able to prevent its ascent thus hindering gastroesophageal reflux. If the latter is particularly severe, the alginic acid gel can be pushed into the esophagus instead of the acidic contents of the stomach, thereby exerting a effect emollient.
To learn more, read also: Gastroprotective drugs Antiulcer drugs
