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H2 Receptor AntagonistAka: H2 Antagonist, Famotidine, Pepcid, H2 Blocker, Ranitidine, Zantac, Cimetidine, Tagamet, Nizatidine, Axid
- Mechanism
- Inhibits histamine action at parietal cell H2 receptor
- Decreases basal and food stimulated acid secretion
- Inhibits 50-80% of daily gastric acid secretion
- Preparations
- Ranitidine (Zantac)
- Bolus IV Dosing: 50 mg IV q6-8h
- Continuous IV Dosing: 6.25 mg/h IV
- Oral Dosing: 150 mg PO bid
- Cimetidine (Tagamet)
- Bolus parenteral dosing: 300 mg IV or IM q6h
- Continuous IV Dosing: 37.5 mg/h IV
- Oral Dosing: 400 mg PO bid
- Famotidine (Pepcid)
- Oral dosing: 20 to 40 mg PO bid
- Nizatidine (Axid)
- Oral dosing: 150 mg PO bid
- Efficacy
- Similar efficacy among all 4 agents
- H2 Blockers are not as effective in Tobacco abuse
- Carafate and Prilosec preferred in this population
- Symptomatic relief of GERD in weeks in 70% of cases
- Devault (1999) Am J Gastroenterol 94:1434
- Disadvantages
- Even generic costs still approch Proton Pump Inhibitors
- (2003) Red Book, Medical Economics Data, Montvale, NJ
- Adverse Effects
- Cimetidine has more drug interactions and side effects
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| Definition (MSH) | A histamine congener, it competitively inhibits HISTAMINE binding to HISTAMINE H2 RECEPTORS. Cimetidine has a range of pharmacological actions. It inhibits GASTRIC ACID secretion, as well as PEPSIN and GASTRINS output. It also blocks the activity of CYTOCHROME P-450 which might explain proposals for use in NEOADJUVANT THERAPY. |
| Definition (CSP) | histamine congener; competitively inhibits histamine binding to H2 receptors, inhibits gastric acid secretion, pepsin, and gastrin output, and blocks the activity of cytochrome P-450. |
| Definition (NCI) | A drug usually used to treat stomach ulcers and heartburn. It is also commonly used in a regimen to prevent allergic reactions. |
| Definition (PDQ) | A histamine H(2)-receptor antagonist. Enhancing anti-tumor cell-mediated responses, cimetidine blocks histamine's ability to stimulate suppressor T lymphocyte activity and to inhibit natural killer (NK) cell activity and interleukin-2 production. Cimetidine also may inhibit tumor growth by suppressing histamine's growth-factor activity and blocking histamine-induced stimulation of vascular endothelial growth factor (VEGF), a pro-angiogenic growth factor. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=39185&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=39185&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C374" NCI Thesaurus) |
| Definition (NCI) | A histamine H(2)-receptor antagonist. Enhancing anti-tumor cell-mediated responses, cimetidine blocks histamine's ability to stimulate suppressor T lymphocyte activity and to inhibit natural killer (NK) cell activity and interleukin-2 production. Cimetidine also may inhibit tumor growth by suppressing histamine's growth-factor activity and blocking histamine-induced stimulation of vascular endothelial growth factor (VEGF), a pro-angiogenic growth factor. (NCI04) |
| Concepts | Organic Chemical (T109)
, Pharmacologic Substance (T121)
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| English | Cimetidine, CIMETIDINE PREPARATION |
| Spanish | cimetidina |
| Credits | Derived from the NIH UMLS (Unified Medical Language System)
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| Definition (MSH) | A competitive histamine H2-receptor antagonist. Its main pharmacodynamic effect is the inhibition of gastric secretion. |
| Definition (NCI) | A propanimidamide and histamine H2-receptor antagonist with antacid activity. Famotidine is a competitive inhibitor of histamine H2-receptors located on the basolateral membrane of the parietal cell, thereby reducing basal and nocturnal gastric acid secretion, resulting in a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli. |
| Concepts | Organic Chemical (T109)
, Pharmacologic Substance (T121)
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| English | Famotidine, FAMOTIDINE PREPARATION |
| Spanish | famotidina |
| Credits | Derived from the NIH UMLS (Unified Medical Language System)
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| Definition (MSH) | A non-imidazole blocker of those histamine receptors that mediate gastric secretion (H2 receptors). It is used to treat gastrointestinal ulcers. |
| Definition (CSP) | N-2-(5-dimethylamino)methyl-2- furanylmethyl thioethyl-N'-methyl-2-nitro-1,1 -ethenediamine; cimetidine analog; H2 histamine receptor antagonist used to treat gastric ulcers. |
| Definition (NCI) | A member of the class of histamine H2-receptor antagonists with antacid activity. Ranitidine is a competitive and reversible inhibitor of the action of histamine, released by enterochromaffin-like (ECL) cells, at the histamine H2-receptors on parietal cells in the stomach, thereby inhibiting the normal and meal-stimulated secretion of stomach acid. In addition, other substances that promote acid secretion have a reduced effect on parietal cells when the H2 receptors are blocked. |
| Concepts | Organic Chemical (T109)
, Pharmacologic Substance (T121)
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| English | Ranitidin, Ranitidine, RANITIDINE PREPARATION |
| Spanish | ranitidina |
| Credits | Derived from the NIH UMLS (Unified Medical Language System)
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| Definition (MSH) | A histamine H2 receptor antagonist with low toxicity that inhibits gastric acid secretion. The drug is used for the treatment of duodenal ulcers. |
| Definition (NCI) | A competitive and reversible histamine H2-receptor antagonist with antacid activity. Nizatidine inhibits the histamine H2-receptors located on the basolateral membrane of the gastric parietal cell, thereby reducing basal and nocturnal gastric acid secretion, resulting in a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli. |
| Concepts | Organic Chemical (T109)
, Pharmacologic Substance (T121)
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| English | Nizatidine, NIZATIDINE PREPARATION |
| Spanish | nizatidina |
| Credits | Derived from the NIH UMLS (Unified Medical Language System)
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