The first generation H 1RAS, such as chlorpheniramine, cyproheptadine, hydroxyzine, etc.
The second generation H 1RAS, such as cetirizine, loratadine, mizolastine, astemizole, etc.
The third generation H 1RAS, such as fexofenadine, norastemizole, decarboxylated loratadine, etc. , mainly used for anti-allergy.
Common antagonists of H 1 receptor
Clotrimme (chlorpheniramine)
Oral: Adults take 4 mg three times a day. Children 0.35mg/kg/ day, divided into 3 ~ 4 times. Intramuscular injection: 5 ~ 20mg/ time.
Atrax (hydroxyzine)
Oral: 25mg, qd ~ qid.
Cinnarizine
Oral: 25mg, qd ~ qid.
Finnegan (promethazine, Finnegan)
Oral: 12.5 ~ 25mg, qd ~ bid. Injection, 2ml containing 50mg, intramuscular injection of 25mg~50mg, qd. You can also add 500 ml of normal saline or 5% glucose solution for intravenous drip, qd.
Cypheptyline
Oral: 2 ~ 4 mg, qd ~ qid.
Ketotifen (ketotifen)
Oral: 1mg, qd ~ bid.
Doxepin (Doxepin)
Oral administration: 25mg ~ 50mg, three times a day.
Sismine (astemizole)
Oral: 10mg, qd.
Terfenadine; Terfenadine
Oral: 60mg, bid.
Cetirizine (Zyrtec)
Oral: 10mg, qd.
Loratadine (loratadine, loratadine)
Oral: 10mg, qd.
Pliny: oral: 2.5 ~ 5 mg, bid.
Avastin (Avastin)
Oral: 8 mg, qd ~ tid. Commonly used H2 receptor antagonists
Cimetid: oral: 200~300mg, tid intravenous drip: 0.4, added to 500 ~ 1000ml 5% glucose solution, qd.
Proglumide (proglumide)
Mechanism of action: It is a gastrin receptor antagonist, which can inhibit the secretion of gastric acid and pepsin. Although its inhibitory effect on gastric acid secretion is weaker than that of cimetidine, this product has low toxicity and no special side effects have been found after long-term administration.
Function: It can be used clinically for duodenal ulcer, especially ulcer and gastritis caused by chronic hyperacidity. Note: Occasionally, there are adverse reactions such as constipation, loose stool, abdominal distension and black stool, which will not affect the continued treatment.
Famotidine (Shu Da)
Mechanism of action: It is an H2 receptor agent. This product is more effective than cimetidine and metronidazole. It is reported that its strength is more than 30 times that of cimetidine and more than 6 times that of metronidazole (ranitidine), and its action time is longer, which is about 1/3 longer than the above two drugs. Therefore, this product has the characteristics of strong drug effect, small side effects and safer use.
Function: It is a good medicine for treating gastric and duodenal ulcer and reflux esophagitis.
Note: There are few adverse reactions, and sometimes headache and constipation may occur. For patients with liver and renal insufficiency, pregnant women and children should use with caution.
Sodium carbenoxolone (gastrin sodium)
Mechanism of action: This product is a glycyrrhetinic succinate semi-ester preparation obtained by hydrolysis of glycyrrhizin (or glycyrrhizin), the main component of Glycyrrhiza uralensis Fisch. Clinical practice has proved that this product has strong anti-ulcer effect and adrenocorticoid effect, and has good curative effect on gastric ulcer. This product does not inhibit gastric acid secretion, interfere with histamine, and has no effect on autonomic nervous system and gastrointestinal motility, but it can combine with pepsin to precipitate in acidic solution, thus reducing the activity of pepsin. It can also enhance the secretion and viscosity of gastric mucus, enhance the resistance of gastric mucosa, prolong the life of gastric mucosal epithelial cells and reduce the shedding of gastric mucosal epithelial cells, thus protecting gastric mucosa from bile reflux and promoting ulcer healing. This product has no inhibitory effect on smooth muscle, so it cannot relieve spasm. It also has antitussive and cholagogic effects.
Function: It can be used for peptic ulcer (mainly gastric ulcer, with poor effect on duodenal ulcer) and Addison's disease.
Note: Adverse reactions mainly include sodium retention and hypokalemia, so the elderly, patients with hypertension, heart disease and liver and kidney diseases should use it with caution.
Methoxybromobenzamide bromopride (stomach, bromopride)
Mechanism of action: This product has obvious effects of regulating gastrointestinal motility and anti-ulcer, effectively inhibiting gastric acid secretion, promoting water-soluble gastric mucus secretion and protecting gastric mucosa. It also has the effects of stopping vomiting and local anesthesia weakness. After taking it, it has a good curative effect on gastric and duodenal ulcers, and has different degrees of improvement on patients' acid regurgitation, abdominal distension, belching and upper abdominal pain. Patients who are ineffective in taking cimetidine can switch to this product and achieve certain curative effect.
Function: It is clinically applicable to gastric and duodenal ulcer, gastric and duodenal enteritis, hemorrhagic proctitis, spastic colon disease, epigastric pain, nausea and vomiting, etc.
Note: Adverse reactions mainly include dizziness, lethargy, fatigue, dry mouth and so on. Different degrees after taking the medicine, but it usually disappears by itself after stopping taking the medicine. This product should not be used with psychotropic drugs.
Ranitidine (Ranitidine, Shandewei)
Oral: 150mg, bid.
Mechanism of action: It is a histamine H2 receptor blocker. Its basic structure is different from that of cimetidine, and its effect is stronger than that of cimetidine. It is characterized by long-term, quick-acting and few side effects. After oral administration, it can effectively inhibit gastric acid secretion 12 hours.
Function: Clinically available precautions such as duodenal ulcer, benign gastric ulcer, postoperative ulcer and reflux esophagitis: adverse reactions are not obvious, but headache, rash and diarrhea are rare. Use with caution in patients with renal insufficiency, and it is forbidden for pregnant women and infants.
Roxey titidine
Mechanism of action: It is a selective antagonist of H2 receptor. Blocking histamine H2 receptor in gastric mucosal parietal cells can effectively inhibit gastric acid secretion, and the curative effect is similar to that of cimetidine, but with fewer side effects.
Function: It is clinically used for gastric and duodenal ulcer, anastomotic ulcer and reflux esophagitis, and also used for administration before anesthesia to prevent aspiration pneumonia.
Precautions: There are adverse reactions such as drowsiness, constipation, nausea, abdominal distension, headache and leukopenia. Use with caution in patients with liver and renal insufficiency, and stop taking medicine when allergic reactions such as rash occur occasionally.