1-drug affecting the gastrointestinal system
TRANSCRIPT
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DRUG USED IN GASTRO
INTESTINAL DISEASE
DR.dr.Asep Sukohar, M.Kes
Department of Pharmacology, Faculty Of Medicine,Lampung University
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Many Drugs
Have applications in the treatment ofgastro intestinal disease
- motility
- digestion
- secretion
- absorption
- peptic ulcers
- delayed gastric emptying in adequate propulsion- diarrhea
- infections and inflammation
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DRUG USED IN PEPTIC ULCERS
DISEASE
Pathogenesis of peptic ulcers not
completely understood
Secretion of acid by gastric parietal cells
regulated by- Histamin
- Asetylcholine
- Gastrin
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AGENT FOR CONTROL OF
GASTRIC ACIDITY ANDTREATMENT OF PEPTIC ULCERS
- Antacids
- H2Receptor antagonists
- Mucosal protective agents
- Others agents
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Antacids
- Cimetidine
- Ranitidine- Famatidine
- Nizatidine
- Alumunium hydroxide
- Calcium carbonate
- Magnesium hydroxide
- Sodium bicarbonate
- Magnesium trisilikate
H2Histamin receptor-blockers
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Mucosal protective agents
- Sucralfate
Studies in human subjects and with animal models of ulcer disease have shown that sucralfate forms an ulcer-adherent complex with proteinaceous exudateat the ulcer site.
In vitro, a sucralfate-albumin film provides a barrier to diffusion of hydrogen ions.
In human subjects, sucralfate given in doses recommended for ulcer therapy inhibits pepsin activity in gastricjuice
by 32%.
In vitro, sucralfate adsorbs bile salts.
- Colloidal bismuth
Inhibitors of proton pump
- Omeprazol
- Lansoprazol
Prostaglandins- Misoprostal: inhibiting the secretion of gastric acidvia G-protein coupled receptor-mediated inhibition of adenylate cyclase,
which leads to decreased intracellular cyclic AMPlevels and decreased proton pumpactivity at the apicalsurface of the
parietal cell
http://www.rxlist.com/script/main/art.asp?articlekey=9900http://www.rxlist.com/script/main/art.asp?articlekey=4033http://www.rxlist.com/script/main/art.asp?articlekey=3547http://en.wikipedia.org/wiki/Gastric_acidhttp://en.wikipedia.org/wiki/G-protein_coupled_receptorhttp://en.wikipedia.org/wiki/Adenylate_cyclasehttp://en.wikipedia.org/wiki/Cyclic_AMPhttp://en.wikipedia.org/wiki/Proton_pumphttp://en.wikipedia.org/wiki/Apical_membranehttp://en.wikipedia.org/wiki/Apical_membranehttp://en.wikipedia.org/wiki/Proton_pumphttp://en.wikipedia.org/wiki/Cyclic_AMPhttp://en.wikipedia.org/wiki/Adenylate_cyclasehttp://en.wikipedia.org/wiki/Adenylate_cyclasehttp://en.wikipedia.org/wiki/Adenylate_cyclasehttp://en.wikipedia.org/wiki/G-protein_coupled_receptorhttp://en.wikipedia.org/wiki/G-protein_coupled_receptorhttp://en.wikipedia.org/wiki/G-protein_coupled_receptorhttp://en.wikipedia.org/wiki/Gastric_acidhttp://www.rxlist.com/script/main/art.asp?articlekey=3547http://www.rxlist.com/script/main/art.asp?articlekey=4033http://www.rxlist.com/script/main/art.asp?articlekey=9900 -
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Antimicrobial agents
- Amoxicillin
- Bismuth compounds
- Claritromycin
- Metronidazole
- Tetracycline
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Antacids
Sodium BicarbonatNaHCO3 + HCl NaCl + H2O + CO2- Active ingredient in backing soda
- Highly soluble
absorbed rapidly from the gut
promote systemic alkalosis and fluid retention
Not recommended for long-term use
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Calcium Carbonate
Ca Co3 + 2 Hcl CaCl2+ H2O + Co2
- More slowly than sodium bicarbonate
- Very effective in neutralyzing in gastric acid
- 10% produced is absorbed
potensial- hypercalcemia
- milk alkali syndrome
- acid rebound
not recommended for long term use
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Magnesium Hydroxide
= Milk of Magnesia
Mg(OH)2+ 2 HCl MgCl2 + 2 H2O
- Prolonging its neutralizing effect
- Magnesium salts
cathartic effect- A small absorbed renal insufficiency
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Magnesium Trisilikate
Mg2Si308(nH2O) +4HT2 mg++ +
3S1O2+(n+2)H2O
- S1O2 - adsorbent- Siliceous nephroliths
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H2HISTAMIN RECEPTOR
ANTAGONITS
Cimetidine }
Ranitidine } 2 major drugs in use
- Capable of over 90% reduction in based foodstimulated, and nocturnal secretion of gastricacid after a single dose
- Promoting the healing of duodenal and gastriculcers and preventing their recurrence.
Famotidine
Nizatidine
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Pharmacological Properties
- H2Rec An. Competitively inhibit the interaction ofhistamine
with H2 receptor
- Highly selective
- Absorption, Fate and Excretion
- H2 Rec. An. . rapidly and well absorbed after oral
ad.
. peak C : 1 or 2 hours
. bioavailability Niz : 91%
. t : 2-3 hours
1-3 hours : nizatidine
. Exc : urine
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- Adverse effects : - headache- dizziness and nausea
- myalgia, skin rashes
- itching
- Drug interactions : - Antacid
- Ketakenazole- cyt. P.450
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Inbitors of H+, K+ATP ase
Omeprazole
Lansoprazole
- Inhibition of gastric acid secretion
- Do not affect gastric motility
- Absorption : rapidly
- Bioavailability : 70%
- 95% bound to plasma protein
- t : 30-40
- Metabolism : hepatic- Exc : urine
- Adverse effects - gastrointestinal
- C.N.S
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PROSTAGLANDIN ANALOGS
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PROSTAGLANDIN ANALOGS
PG E2}
}
PGI2 }
- Predominant PG synthesized the gastric mucosa
- Inhibit the secretion acid
- Stimulate the secretion of mucus and
- bicarbonat
Misoprostol
- 1.5 deoxy 16 hydroxy 16-metyl PGE1- Available in the U.S
- Effective in treating - duodenal and
- gastric ulcers
inhibits gastric acid secretion
produce cyproprotective effects
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Pancreatic Enzime
Replacement Product
Two mayor types of preparation in use
- Pancreatin } amylase
} trypsim-Pancrelipase } lipase
- Pepsime
- Pancreatime
- Dyastase
- Dehidrocyolate acid
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Irritant or stimulant laxatives
- Castor oil
- Cascara }
- Senna } Difenilmetane
- Aloes }
- Phenolphtalien }
} Anthrakinon
- Bisacodyl }
peristalsis is stimulated
Laxatives
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Drugs promoting
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Drugs promoting
Gastrointestinal motility
* Bethanecol cholinergic agonist
* Metoclopramide
- Facilitating small bowel inhibition
- Gastric motor failure
- Particularly diabetic gastroporesis
- After vagotomy- Disorders of gastric emptying
- Gastroesophageal reflux disease
- cancer chemotherapy
- Rapidly absorbed- Peak C : 40 120
- t : 4 hours
- Excretion : kidneys
- 10 mg 4 times daily - neal
- bed time
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Most widelly used prescription drugs1. Diphenoxylate (with atropine)
analog of meperidine
2. Loperamide
haloperidol
mechanisme of action : similar to that of the opioids
Kaolin } adsorbents
Pectin }
also widely used
Antidiarrheal Drugs
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Drugs Used in The Treatment of Bowel Chranic
Inflammatory Bowel disease
ulcerative collitis
chrohms disease
- Corticosteroids
- Other immunosuppressive agents
Sulfasalazine
combines sulfapyridine
- 5 aminosalicylic acid
poorly absorbed from the intestine
MOA unknown
cytoprotective role ?
3-4g daily individed doses
Azodisalicylate
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How to formulate drugs?GG 979
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Clinical Summary GG 980