DRUGS USED IN GASTRO-INTESTINAL DISORDERS.

MR. ABDOU MARAM PANNEH

(RM ,FWACN,NT, RN)

INTRODUCTIONDrugs used in Gastro-intestinal disorders can

be grouped into four categories:- These are:-

1. ANTIDIARRHOEALS & FLATULANTS2. ANTIEMETICS & EMETICS3. LAXATIVES4. ANTI PEPTIC ULCER DISEASE

ANTIDIARRHOEAL & ANTIFLATULANT DRUGS  

These are drugs used as adjuncts in the symptomatic treatment of acute or chronic diarrhea. The main aim in the management of diarrhea is to correct fluid and electrolyte depletion. Therefore, their use should be limited to chronic diarrhea since the treatment is aimed at treating the underlying cause. Acute diarrhea may be self-limiting.

ADR:- Constipation, nausea, vomiting, abdominal distension, headache, dizziness, blurred vision, swelling of gums, etc

INTERACTIONS:- Alcohol increases the risk of hypertensive crises.DRUGS COMMONLY USED:-

Diphenoxynate (Lomotil, Lomanate) 2.5mg tabs or suspensionLoperamide (Imodium) 2mg, 4mg, tabs or capsRoxid syrup (Nifuroxazide) 400mg.Kaolin MixturePectin tabsCodeine phosphate 15mg, 30mg tabsMorphine tabs

ANTIEMETICS & EMETICS ANTIEMETICS

These are a diverse group of drugs used to treat or prevent nausea, vomiting and motion sickness. The choice of drug largely depend on the cause of nausea and vomiting especially in children. They are therefore unnecessary or harmful if the cause can be treated.

CLINICAL USES:-Used to treat nausea, vomiting and motion sickness.They act on the H1 receptor sites, chemoreceptor zone,

cerebral cortex or vestibular apparatus which suppresses the vomiting center.

They are also used in conjunction with histamine 2-receptor antagonists and proton pump inhibitors in the treatment of gastro intestinal reflux disease.

2.  ANTIEMETICS & EMETICS Cont’d..

ADR:- drowsiness, headache, dizziness, diarrhea, constipation, extrapyramidal reactions, fatigue, sedation, hypotension, tolerance, diarrhea, oliguria, dry mouth, etc

INTERACTIONS:- Levodopa( causes a decrease in levodopa antiparkinsonian effect)

DRUGS COMMONLY USED:-These drugs are grouped into 5 main categories:1. Selective serotonin antagonists- or 5HT3 antagonists

(most effective)- Ondasetron (Zofran) 1mg injection.- Granisetron (Kytril) 1mg, 2mg, tabs- Dolasetron (Anzemet)2. Dopamine Antagonists;- These are sub-divided into

three.a. Phenothiazines:- - Chlorpromazine (largactil) 25mg,

50mg tabs/inj.- Prochlorperazine (stemetil) 5mg tabs - Promethazine (phenergan) 25mg, 50mg tabs/injb. Butyrophenones:- Haloperidol(Haldol) 5mg tabs

Domperidone(Motilium) 10mg tabsc. Prokinetics:- Metochlopropramide (Reglan, Maxolone)

10mg tabs

ANTIEMETICS & EMETICS Cont’d..3. Antihistamines:- used mainly in motion sickness ,

nausea, vomiting, Tinnitis and vertigo .Meclozine (Antivert) tabsCinnarizine (Stugeron) 15mg, tabs/capsCyclizine (Valoid) 50mg tabs, Promethazine,

Chlorpromazine, etc. 4. Glucocorticoids:- used mainly as Antiemetics in

cancer cases- Methylprednisolone (Solu-medrol)- Dexamethasone5. Benzodiazepines:- Lorazepam (Ativan),

Bromazepam (lexotan, lexomil) 3mg, 6mg,Diazepam (Valium)5mg, 10mg, Oxazepam10mg tabs.

 LAXATIVES OR PURGATIVES 

LAXATIVES OR PURGATIVES are drugs mainly used to:-treat temporal or chronic constipationpromote defecationfacilitate bowel evacuation before special

investigations such as endoscopy, radiological examination or surgery.

The use of laxatives must be done with great caution as abuse may lead to toxicity.

Laxatives may be classified according to their mode of action. There is however, a degree of overlap between the various groups and in some cases, the precise mechanism of action is not well understood.

LAXATIVES OR PURGATIVES Cont’d.. 

Laxatives ca be grouped into 4 main areas commonly used in clinical practice:-

A. Bulk Forming/Bulking Laxatives:- They cause retention of fluid and an increase in fecal mass resulting stimulation of peristalsis.

EXAMPLES:- Bran, Agar, Ispaghula Methylcellulose

B.Irritant or Stimulating Laxatives:- they act by directly stimulating nerve endings in the colonic mucosa, thereby increasing motility.

EXAMPLES:- Castor oil, Sennakot 7.5mg tabs, Aloes, Bisacodyl (Ducolax) 5mg tabs.

 LAXATIVES OR PURGATIVES Cont’d.. C. Osmotic Laxatives:- they act by increasing

intestinal osmotic pressure thereby promoting retention of fluid within the bowel.

EXAMPLES:- Lactulose (Duphalac), Sorbitol (Microlax), Rectal phosphate, Magnesium cinfa, Magnesium hydroxide, Herbal Teas, etc

D.Fecal or Stool softeners (Emollient laxatives):- these group act by decreasing surface tension and increase penetration of intestinal fluid into the fecal mass.

EXAMPLES:- Liquid paraffin, Glycerin suppositories, Mineral oil 

ANTI PEPTIC ULCER DISEASE DRUGS These drugs are used in the management of peptic ulcer disease conditions such as Gastric, Duodenal or Jejunal ulcers.

They can be grouped into four main categories. Antacids Gastric antisecretory agents Mucosal protectants Antibacterials  

A. ANTACIDS Gastric antacids are weak base agents that reacts with gastric

hydrochloric acid to form water and salts. They can reduce or neutralize gastric and peptic acidity. The benefits of antacids in gastric ulcers is not clear but they can be effective in promoting cure for gastric and duodenal ulcers, dyspepsia, oesophageal reflux, indigestion, etc.

A single dose given one hour after meals can effectively neutralize gastric acidity for 2hrs.

ADR:- Constipation

 ANTI PEPTIC ULCER DISEASE DRUGS  COMMON DRUGS USED:-

Magnesium Trisilicate tabs/suspensionAluminum Hydroxide tabs/suspensionMaalox (magnesium trisilicate+aluminum hydroxide)Gaviscon (sodium bicarbonate+sodium alginate)GastrogelSimeticonRennie (calcium carbonate+mag. sulphate)

B. GASTRIC ANTI SECRETORY AGENTS:-These drugs can be grouped into three categories:-i. Histamine2 receptor antagonistsii. Antimuscarinic agentsiii. Proton pump inhibitorsThe combination of these three group of drugs are often

referred to as ulcer healing drugs.

ANTI PEPTIC ULCER DISEASE DRUGS Cont’d..  i. Histamines2 receptor antagonists:-These products can reduce daytime secretions but

they can be more effective in night secretions. They suppress the secretion of gastric acid and decrease pepsin in the stomach.

ADR:- headache, gynaecomastia, confusional state.INTERACTION:- Warfarin, Theophyllin & Diazepam

– their effects are slowed by Cimetidine.COMMON DRUGS USED:

Cimetidine (Tagamet) 200mg, 400mg tabs/injRanitidine (Zantac) 150mg, 300mg, tabs/injFamotidine 20mg tabsNizatidine, Sucralfate, etc

ANTI PEPTIC ULCER DISEASE DRUGS Cont’d.. ii. Antimuscarinic agents:-These drugs act on the central nervous system or peripherals

to control vagal effect and intestinal muscle spasms causing pain in the abdominal region.

ADR:- constipation, transient Bradycardia, reduced bronchial secretions, urinary urgency & retention, dry mouth, dryness of skin,nausea and vomiting, photophobia, mydriasis etc.

COMMON DRUGS USED:-Atropine Sulphate 600mcgHyosine butylbromide (Buscopan) 10mg tabsPropantheline bromide(Pro-Banthine) 15mg tabsAlverine citrate (Spasmonal, spasfon) 60mg tabsMebeverine hydrochloride (Colofac) 50mg, 135mg tabsPeper mint oil caps/tabsScopolamine

4. ANTI PEPTIC ULCER DISEASE DRUGS Cont’d.. iii. Proton Pump Inhibitors:-These group of drugs are called pro drugs because they need

activation in an acid environment such as the stomach.They help in gastroesophageal reflux and esophagitis.They irreversibly inhibit gastric parietal cells proton pump

secretion.A single daily dose can effectively inhibit gastric acid secretion

at 100% (24hrs).All these druga are effective for short term treatment for at

least 4 to 8 weeks.ADR:- dry mouth, taste disturbances, constipation.COMMON DRUGS USED:

Omeprazole (Losec, Omimac, Omagen) 20mg, 40mg capsLansoprazole (Zoton, Heliclear) 15mg, 30mg capsEsomeprazole (Nexium)Pantoprazole (Protium) 20mg, Rabeprazole (Pariet) 10mg,

20mg caps/tabs.

ANTI PEPTIC ULCER DISEASE DRUGS Cont’d.. C MUCOSAL PROTECTANTS:-These group of drugs can be divided into two main categories:-i. Chelates or Complexesii. Prostaglandins i. The ChelatesThese drugs coat th e gastric mucosa mainly at the site of the

ulceration by forming an adherent complex with proteins.They also have an antibacterial role in the treatment of

helicobacter pylori which is the causative agent for ulcer.ADR:- abdominal pain, dyspepsia, nausea, vomiting, dizziness, etcCOMMON DRUGS USED:-

Sucralfate (Carafate) 1gm tabsTripotassium decitratobismuthate 120mg tabs

4. ANTI PEPTIC ULCER DISEASE DRUGS Cont’d..ii. The PostaglandinsThese drugs act by stimulating the synthesis of the protective

mucus layer.COMMON DRUGS USED:-

Misoprostol (Cytotec) 200mcgsCetraxate, Ecabet, Carbenoxolone, Benexate, Ebrotidine,

Rebamipide. D. ANTIBACTERIALSThese drugs are used in combination with the anti ulcer drugs

aimed to eradicate the helicobacter pylori.COMMON DRUGS USED:-

Macrolides:- Clarithromycin 250mg, 500mg. Azithromycin 500mgPenicillins:- Amoxycillin 500mg, Ampicillin 500mgQiunolones:- Ciprofloxacin 250mg, 500mg tabs. Ofloxacin,

Norfloxacin.Tetracycline, Metronidazole (Flagyl), Tinidazole, etc.

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Lippincott Willians and Wilkins.British National Formulary 2009, London WC1H 9JP, UKGoodman and Gilman`s. The pharmacological basis

therapeutics.Morton J.R(BSN,PH.d.), Dorothy W.S.- Pharmacology and

drug therapy in nursing. J.B Lippicott company. Toronto, USA.

Hall.J.W.: Drug therapy in infectious diseases. Am.J. Nursing, 61:56. 1961

The Gambia Standard Drug Treatment Manual, MOHSW, Banjul. July 2005,

British National Formularly. BMA, Tavistock Square, London WC1H 9JP, UK, 2008 series. 

QUESTIONS, CONTRIBUTIONS,

CLARIFICATIONS & CONSTRUCTIVE

CRITICISMS?????