1-Drug Affecting the Gastrointestinal System

8/10/2019 1-Drug Affecting the Gastrointestinal System

1/27

DRUG USED IN GASTRO

INTESTINAL DISEASE

DR.dr.Asep Sukohar, M.Kes

Department of Pharmacology, Faculty Of Medicine,Lampung University


2/27

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


3/27

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


4/27

AGENT FOR CONTROL OF

GASTRIC ACIDITY ANDTREATMENT OF PEPTIC ULCERS

- Antacids

- H2Receptor antagonists

- Mucosal protective agents

- Others agents


5/27

Antacids

- Cimetidine

- Ranitidine- Famatidine

- Nizatidine

- Alumunium hydroxide

- Calcium carbonate

- Magnesium hydroxide

- Sodium bicarbonate

- Magnesium trisilikate

H2Histamin receptor-blockers


6/27

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


7/27

Antimicrobial agents

- Amoxicillin

- Bismuth compounds

- Claritromycin

- Metronidazole

- Tetracycline


8/27

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


9/27


10/27

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


11/27

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


12/27

Magnesium Trisilikate

Mg2Si308(nH2O) +4HT2 mg++ +

3S1O2+(n+2)H2O

- S1O2 - adsorbent- Siliceous nephroliths


13/27

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


14/27

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


15/27

- Adverse effects : - headache- dizziness and nausea

- myalgia, skin rashes

- itching

- Drug interactions : - Antacid

- Ketakenazole- cyt. P.450


16/27


17/27

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


18/27

PROSTAGLANDIN ANALOGS


19/27

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


20/27

Pancreatic Enzime

Replacement Product

Two mayor types of preparation in use

- Pancreatin } amylase

} trypsim-Pancrelipase } lipase

- Pepsime

- Pancreatime

- Dyastase

- Dehidrocyolate acid


21/27

Irritant or stimulant laxatives

- Castor oil

- Cascara }

- Senna } Difenilmetane

- Aloes }

- Phenolphtalien }

} Anthrakinon

- Bisacodyl }

peristalsis is stimulated

Laxatives


22/27

Drugs promoting


23/27

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


24/27

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


25/27

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


26/27

How to formulate drugs?GG 979


27/27

Clinical Summary GG 980

Date post:	02-Jun-2018
Category:	Documents
Upload:	crystal-arnold
View:	216 times
Download:	0 times

1-Drug Affecting the Gastrointestinal System

Documents