18. UNIT 5-GIT DRUGS_A_TK.pptx..........

Gastrointestinal tract drugs

1. Tuesday, August 15, 2023 1

2. UNIT 5 DRUGS ACTING ON THE GIT Tuesday, August 15, 2023 2

3. Introduction In this unit, we will learn about drugs acting on the gastrointestinal tract. The gastro intestinal tract runs from the mouth to the anus Tuesday, August 15, 2023 3

4. General objective At the end of this unit, student nurses should be able to acquire knowledge on the drugs acting on the GIT and be able to nurse the patients with GIT conditions. Tuesday, August 15, 2023 4

5. Specific objectives Students should describe the following drugs; Anti-acids Antispasmodics Proton Pump inhibitors H 2 receptor anatgonists Emetics Anti-emetics Anticholinergic agents Laxatives Tuesday, August 15, 2023 5

6. Specific objectives cont’d 9. Purgatives 10. Anti-diarrhoeal drugs 11. Suppositories 12. Rectal infusions 13. Anti- helminths Tuesday, August 15, 2023 6

7. Anti-Acids Tuesday, August 15, 2023 7

8. Antiacids Antacids are alkaline substances that neutralize stomach acid to treat symptoms of heartburn. Although antacids relieve symptoms of heartburn , they do not promote ulcer healing or help to eliminate H . pylori . Action: Neutralise gastric acid by increasing the gastric PH . Tuesday, August 15, 2023 8

9. Antiacids cont’d Neutralization of gastric acid relieves pain caused by hyperacidity in case of peptic ulcer disease . Antiacids are best given when symptoms occur or are expected, usually between meals and at bedtime. Antacids should not be given at the same time with drugs like tetracycline, Chloroquine , artemether lumenfatrine . 9 Tuesday, August 15, 2023

10. Example of Antiacids: Aluminum hydroxide ( AlternaGEL ) Calcium carbonate ( Titralac ) M agnesium hydroxide (Milk of Magnesia) , M agnesium trisilicate and aluminum hydroxide (MMT) Sodium bicarbonate (Baking soda) Tuesday, August 15, 2023 10

11. Aluminium hydroxide(AlternaGEL) Presentation: Tablet chewable 500mg and mixture 250mg/5ml. Indication: Hyperacidity and Peptic ulcers. Dose : chew 500 mg tid–qid , half an hour before or after meals. Side effects : Constipation, nausea, fecal impaction, hypophosphatemia with chronic use. Tuesday, August 15, 2023 11

12. Calcium Carbonate (Titralac, Tums) Presentation: tab 500mgs, 1g Indication: Hyperacidity and Peptic ulcers. Dosage : PO: 1–2 g bid– tid Side Effects : Constipation, flatulence, Fecal impaction, metabolic alkalosis, hypercalcemia , and renal calculi. Tuesday, August 15, 2023 12

13. M agnesium hydroxide (Milk of Magnesia) Presentation: 130 mg per tablet,chewable tablet, Indications: Hyperacidity, peptic ulcer. Dose: Adult: 130 mg od . Side-Effects : Diarrhoea, nausea, vomiting, abdominal cramping, Hypermagnesaemia (patients with renal disease ), dysrhythmias (when given parenterally Caution: Give with caution in patients with Impaired renal function. Tuesday, August 15, 2023 13

14. Magnesium Trisilicate & Aluminum Hydroxide (MMT) Presentation: Magnesium trisilicate tablet compound containing magnesium trisilicate 250mg, aluminium hydroxide 120mg. Indications: dyspepsia, hyperacidity and Peptic ulcers Dosage: tablet: 1 -2 tabs to be chewed 3-4 times in a day in between meals and at bedtime when required.. Contra-indications: hypophosphatemia Side effects: diarrhoea , belching . 14 Tuesday, August 15, 2023

15. Nursing implications: With prolonged use watch for symptoms of hypermagnesia such as ( respiratory depression and coma). Tuesday, August 15, 2023 15

16. Sodium bicarbonate (Baking soda) Indication: dyspepsia, hyperacidity and Peptic ulcers. Dosage: PO: 325 mg–2 g 1 to 4 times/day Side effects: Abdominal distention, belching, metabolic alkalosis, fluid retention, edema and hypernatremia Tuesday, August 15, 2023 16

17. Mucosal Protective Sucralfate. Misoprostol Bismuth. Polaprezine. Carbenoxolone , Tuesday, August 15, 2023 17

18. Sucralfate (Crafilm ) Action: stimulates mucus, bicarbonate, and prostaglandin secretion which enhance mucosal defenses by protecting it against erosion from acid and pepsin. Indications: Gastric,duodenal ulcers & chronic gastritis. Dosage: 1g-2g twice daily or 1g 4 times daily. 1 hour before meals and at bedtime, taken for up to 6 weeks Side effect: Constipation; diarrhoea , nausea, gastric discomfort, dry mouth, rash, pruritus , dizziness, insomnia, vertigo. . Tuesday, August 15, 2023 18

19. Misoprostol ( Cytotec ) Action: Is a synthetic form of prostaglandin E2 that stimulates the production of protective mucus and inhibits gastric acid secretion. Indication: Prevention of gastric ulcers in patients who are taking high doses of NSAIDs. Dose: Gastric or duodenal ulcer 800mcg in 2 - 4 divided doses with meals. Treatment should be continued for at least 4 weeks. Tuesday, August 15, 2023 19

20. Side effects : Diarrhea, abdominal cramping. Contraindicated: pregnancy, this drug is combined with mifepristone for pregnancy termination Tuesday, August 15, 2023 20

21. Antispasmodics Tuesday, August 15, 2023 21

22. Antispasmodics These are antimuscarinic drugs which reduce gastro-intestinal motility. They reduce spasm, delaying gastric emptying time and thus prolonging the action of antacids. Tuesday, August 15, 2023 22

23. Propanthelin Bromide Presentation: Tabs 15mg. Action: anticholinergic , muscarinic antagonist and antispasmodic drugs Indications: Adjunct in gastro-intestinal disorders characterized by smooth muscle spasm, urinary incontinence, peptic ulcers. Dose: 15mg 3 times daily 1 hour before meals and 30mg at bedtime. Side effects: Dry mouth, dilatation of pupils, constipation and hyperpyrexia. Contraindications : Children and Glaucoma. Tuesday, August 15, 2023 23

24. Hyoscine butylbromide (Buscopan) Presentation: Tabs 10mg, Injection 20mg/ml. Indications: Adjunct in gastro-intestinal disorders characterized by smooth muscle spasm, irritable bowel syndrome & smooth muscle spasm conditions (period pains). Dose : Adult; 20mg 3 - 4 times daily. Child, 6 – 12 years; 10mg 3 times daily. Side effects: Dry mouth, tachycardia, difficulty in micturition, dilatation of pupils, constipation and hyperpyrexia. Contraindications: Glaucoma Tuesday, August 15, 2023 24

25. Atropine Sulphate ( Atrolate) Indications: Used prior to administration of general anaesthesia . Concomitantly used with Neostigmine to counteract muscarinic effects. Used as antidote for organophosphate insecticide poisoning, mushroom poisoning. Dosage; 0.4-0.6mg IV, Children; 0.02mg/kg body weight IV or IM . Tuesday, August 15, 2023 25

26. Atropine Cont’d Contra-indications: Closed angle glaucoma, paralytic ileus . Side effects: altered taste perception, nausea, vomiting, dysphagia , heartburn, constipation,paralytic ileus photo phobia, Palpitation, bradycardia . Tuesday, August 15, 2023 26

27. Ulcer healing Drugs Tuesday, August 15, 2023 27

28. H2-Receptor Antagonists Histamine has two types of receptors: H1 and H2. Activation of H1 receptors produces the classic symptoms of inflammation and allergy, whereas the H2 receptors, located on the parietal cells in the stomach, promote gastric acid secretion when activated. The H2 receptor antagonists effectively reduce both fasting and food-stimulated secretion & also helpful in decreasing nocturnal acid secretion, which is largely dependent histamine. . 28 Tuesday, August 15, 2023

29. H2-Receptors Antagonists cont’d Action: acts by blocking H 2 receptors on the parietal cells in the stomach to decrease acid production of daytime and nocturnal period. Examples of H2-Receptor Antagonist: Cimetidine (Tagamet) Ranitidine (Zantac) famotidine (Pepcid) Nizatidine (Axid ) Indications: duodenal ulcers, gastric ulcers, hypersecretory conditions like Zollinger-Ellison's Syndrome . , heartburn, and GERD. Tuesday, August 15, 2023 29

30. H2-Receptor Antagonists Drug Dosage/Route Side Effects Cimetidine (Tagamet) Active ulcers: PO: 200 mg every 6 h or 800 mg at bedtime or 400 mg bid with food; IV: 200 mg every 6 h (over a minimum of 5 min) or GERD: 400 mg every 6 h or 400 mg bid for 12 weeks Dizziness, rash, tiredness; reversible confusional states, reversible liver damage, headache, decreased, blood counts, muscle or joint pain, hypersensitivity,Pain at I.M. injection site . Hypotension Ranitidine (Zantac) Active ulcers: PO 150 mg bid or 300 mg once daily after the evening meal. IV/ lM : 50 mg every 6–8 h by intermittent bolus or infusion Famotidine (Pepcid) . Active ulcers: PO: 40 mg OD day for 4–8 weeks, then 20 mg at bedtime GERD: PO: 20 mg bid for 6 weeks IV: 20 mg every 12 h Nizatidine (Axid) Active ulcers: PO: 150 mg bid or 300 mg at bedtime GERD: PO: 150 mg bid IV: 20 mg every 12 h Tuesday, August 15, 2023 30

31. Nursing Responsibilities: H2 Receptor Antagonists Take H2-receptor antagonists with or immediately after meals. Immediately report severe or persistent diarrhea accompanied by fever to the health care provider. Advise patient to avoid alcohol while taking cimetidine to prevent interaction. Be aware that rapid administration of cimetidine can increase risk of arrhythmias and hypotension. Tuesday, August 15, 2023 31

32. Proton Pump Inhibitors (PPIs) Action: A ct by blocking hydrogen potassium-adenosine triphosphatase (H+K+- ATPase ) enzyme system, the enzyme that is responsible for secreting hydrochloric acid in the stomach’s parietal cells. In other ways, PPIs reduces acid secretion in the stomach by binding irreversibly to the enzyme H ,K -ATPase . Or It inhibits the final pathway involved in acid secretion and effectively inhibits the active proton pumps. 32 Tuesday, August 15, 2023

33. Mode of action Tuesday, August 15, 2023 33

34. Examples of PPIs include: Omeprazole (Prilosec) Lansoprazole (Prevacid), Esomeprazole (Nexium), Pantoprazole (Protonix), Rabeprazole (Aciphex ) Tuesday, August 15, 2023 34

35. Proton Pump Inhibitors (PPIs) Drug Dose/Route Side Effects Esomeprazole (Nexium) PO: 20–40 mg daily or bid for up to 8 weeks IV: 20–40 mg daily for up to 10 days Diarrhea, nausea, rash, abdominal pain Increased risk for osteoporosis related fractures of the hip, wrist, or spine, and gynaecomastia. Contra-indications: hypersensitivity, children less than 2 years, pregnancy and liver disease. Lansoprazole (Prevacid) PO: 15–30 mg daily for 4–8 weeks IV: 30 mg over 30 min daily for up to 7 days Omeprazole (Omega or Prilosec) PO: 20–60 mg daily or bid for 8 weeks. Pantoprazole (Protonix) PO: 40 mg daily or bid IV: 40 mg IV daily for up to 7 days Rabeprazole (AcipHex) PO: 20–60 mg once daily Tuesday, August 15, 2023 35

36. Nursing Implication of PPIs Take drugs 30min before meals or before breakfast. Do not crush or chew the tablets or capsules. Lansoprazole granules from the capsule may be sprinkled into soft foods such as sauce. Afterward, drink a full glass of water to ensure drug is ingested. Report severe or persistent diarrhea accompanied by fever to health care provider. Be aware that long-term use of omeprazole may risk into gastric carcinoma. Tuesday, August 15, 2023 36

37. Pharmacotherapy of Helicobacter pylori Infection It is estimated that 60% to 80% of patients with gastrial -duodenal ulcers are infected with H. pylori and that the majority of patients with ulcers have the bacterium. Research has shown that the eradication of H. pylori decreases the recurrence of PUD. Tuesday, August 15, 2023 37

38. Drug used to eradicate H. pylori: Initial regimen (Triple Therapy): Omeprazole , C larithromycin, and Amoxicillin Alternative regimens: Omeprazole (or other PPI), C larithromycin and M etronidazole or Omeprazole (or other PPI), Bismuth subsalicylate, Metronidazole, and tetracycline Omeprazole, Amoxicillin and Metronidazole Tuesday, August 15, 2023 38

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40. THE END THANK YOU Tuesday, August 15, 2023 40