Gastrointestinal drugs

• Gastrointestinal drugs are a class of medications used to treat gastrointestinal disorders.

Classification:

1. Gastric acid secretion inhibitors:
   • H₂ Antihistamines: Cimetidine, Ranitidine, Famotidine, Roxatidine
   • Anticholinergics: Pirenzepine, Propantheline, Oxyphenonium
   • Proton pump inhibitors: Omeprazole, Esomeprazole, Pantoprazole, Lansoprazole, Dexrabeprazole, Rabeprazole
   • Prostaglandin analogue: Misoprostol
2. Gastric acid neutralizers (Antacids):
   • Systemic: Sod. bicarbonate, Sod. citrate
   • Nonsystemic: Magnisium hydroxide, Magnisium trisilicate, Alumin. hydroxide, Magaldrate, Calicium carbonate
3. Ulcer protectives: Sucralfate, Colloidal bismuth subcitrate (CBS)
4. Anti H. pylori drugs: Amoxicillin, Clarithromycin, Metronidazole, Tinidazole, Tetracyclin, CBS

1. Anticholinergics: Hyoscine, Dicyclomine
2. Neuroleptics (D2 blockers): Chlorpromazine, Triflupromazine, Prochlorperazine
3. Prokinetic drugs: Metoclopramide, Domperidone, Cisapride, Mosapride, Iropride
4. NK₁receptor antagonists Aprepitant, Fosaprepitant
5. H₁ antihistaminics: Promethazine, Diphenhydramine, Dimenhydrinate Doxylamine, Meclozine (Meclizine)
6. 5-HT₃ antagonists: Ondansetron, Granisetron, Palonosetron, Ramosetron
7. Adjuvant antiemetics: Dexamethasone, Benzodiazepines, Dronabinol, Nabilone

1. Bulk forming agents:bran (Dietary fire), Psyllium (plantago), Ispaghula, Methyl cellulose
2. Stool softener: Docusates (DOSS), Liquid paraffin
3. Osmotic purgatives:Magnesium sulfate, Magnesium hydroxide, Sodium sulfate, Sodium phosphate, Sodium pottasium tartrate, Lactulose
4. Stimulant purgativesP:
   • Diphenylmethanes:Phenolphthalein, Bisacodyl, Sodium picosulfate
   • Anthraquinones (Emodins): Senna, Cascara sagrada
   • 5-HT₄ agonist: Prucalopride
   • Fixed oil: Castor oil

1. Antimicrobial drugs: Norfloxacin, Ciprofloxacin, Rifaximin, Cotrimoxazole, Ampicillin, Tetracycline, Erythromycin, Metronidazole
2. Probiotics: Lactobacillus sp., Bifidobacterium bifidum, Strep. faecalis, Enterococcus sp., Bacillus clausii, Saccharomyces boulardii
3. Drugs for inflammatory bowel disease:
   • 5-ASA compounds: Sulfasalazine, Mesalazine, Balsalazide, Olsalazine
   • Glucocorticoids:Prednisolone, Hydrocortisone (enema)
   • Immunosuppressants: Azathioprine, Methotrexate, Cyclosporine, Infliximab
4. Nonspecific antidiarrhoeal drugs:
   • Absorbants/adsorbants: Ispaghula, Methylcellulose, Kaolin, Pectin
   • Antisecretory drugs: Rasecadotril,, Bismuth subsalicylate, Anticholinergics, Octreotide
   • Antimotility drugs Codeine, Diphenoxylate, Loperamide

1. Inhibit cell wall synthesis: Penicillins, Cephalosporins, Carbapenems, Monobactams, Vancomycin, Cycloserine, Bacitracin
2. Inhibit protein synthesis: Tetracyclines, Chloramphenicol, Erythromycin (other macrolides), Clindamycin, Linezolid
3. Cause misreadingnof m-RNA → affect permeability: Aminoglycosides (Streptomycin, Gentamicin, others)
4. Interfere with DNA function: Rifampin
5. Cause leakage from cell membranes: Polymyxin, Colistin, Bacitracin, Amphotericin B
6. Inhibit DNA gyrase: Ciprofloxacin
7. Interfere with intermediary metabolism Sulfonamides, Sulfones, Trimethoprim, Pyrimethamine, Para aminosalicylic acid, Metronidazole

1. Short acting: Sulfadiazine
2. Intermediate acting: Sulfamethoxazole
3. Long acting: Sulfadoxine, Sulfamethopyrazine
4. Special purpose: Sulfacetamide sodium, Sulfasalazine, Silver sulfadiazine, Mafenide

1. Natural penicillin: Benzyl penicillin (Penicillin G)
2. Semisynthetic penicillins:
   • Acid - resistant alternative to penicillinG: Phenoxymethyl penicillin (Penicillin V)
   • Penicillinase resistant penicillins: Methicillin, Cloxacillin, Dicloxacillin
   • Extended spectrum penicillins:
     • Amino penicillins: Ampicillin, Bacampicillin, Amoxicillin
     • Ureido penicillins Piperacillin, Mezlocillin
     • carboxy penicillins Carbenicillin
3. β-lactamase inhibitors: Clavulanic acid, Sulbactam, Tazobactam

1. First generation:
   • Oral: Cephalexin, Cefadroxil
   • parenteral: Cefazolin
2. Second generation:
   • oral: Cefaclor, Cefuroxime axetil, Cefprozil
   • parenteral: Cefuroxime, Cefoxitin
3. Third generation:
   • oral: Cefixime, Cefpodoxime proxetil, Cefdinir, Ceftibuten, Ceftamet pivoxil
   • parenteral: Cefotaxime, Ceftriaxone, Ceftizoxime, Ceftazidime, Cefoperazone
4. Fourth generation:
   • Parenteral: Cefepime, Cefpirome

1. First line drugs: Isoniazid, Rifampin, Pyrazinamide, Ethambutol, Streptomycin
2. Second line drugs:
   • Fluoroquinolones: Ofloxacin, Levofloxacin, Moxifloxacin, Ciprofloxacin
   • Injectable drugs: Kanamycin, Amikacin, Capreomycin
   • Other oral drugs: Ethionamide, Prothionamide, Cycloserine, Terizidone, Para amino salicylic acid (PAS), Rifabutin, Thiacetazone

1. Group I - First line oral drugs: Isoniazid, Rifampin, Pyrazinamide, Ethambutol
2. Group Il - Injectable drugs: Streptomycin, Kanamycin, Amikacin, Capreomycin
3. Group Ill - Fluoroquinolones: Ofloxacin, Levofloxacin, Moxifloxacin, Ciprofloxacin
4. Group IV - Second line oral drugs: Ethionamide, Prothionamide, Cycloserine, Terizidone, Para amino salicylic acid
5. Group V - Unclear efficacy drugs: Thiacetazone, Prothionamide, Clarithromycin, Clofazimine

1. Sulfone: Dapsone
2. Phenazine derivative: Clofazimine
3. Antitubercular drugs: Rifampin, Ethionamide
4. Other antibiotics: Ofloxacin, Moxifloxacin, Minocycline, Clarithromycin