Antiulcer Drugs | Physiomentor

ANTIULCER DRUGS:

Antiulcer drugs or medications which block the pathways of acids production or secretion, decreasing gastric acidity, improving symptoms and aids in healing of acid peptic diseases.

DEFINITION:

Antiulcers are a class of drugs exclusive of antibacterial agents and used to treat ulcers in stomach and upper part of small intestine.

Classification of Antiulcer Drugs:

Antihistamines:

• Cimetidine
• Famotidine
• Roxatidine
• Ranitidine
• Nizatidine

Proton Pump inhibitors:

• Omeprazole
• Pantoprazole
• Esmoprazole
• Lansoprazole
• Rabeprazole

Anticholenergics:

• Pirenzepine
• Oxyphenonium
• Propantheline

Prostaglandin Analogue:

• Misoprostol

Acid Neutralizing Agents (Antacids):

• Systemic: Sodium bicarbonate
• Non-systemic: Calcium carbonate

Anti H.Pylori Drugs:

• Amoxicillin
• Tetracycline
• Clarithromycin
• Tinidazole
• Metronidazole

Ulcer Protectives:

• Sucralfate
• Colloidal bismuth sub citrate

Pharmacokinetics:

Bioavailability: Approximately 50% (instability at acidic pH).

Metabolism: Antiulcers are metabolized by liver.

Excretion: Metabolites are excreted through renal system.

Duration of action: 24 hours

Mechanism of Action:

• Block last step in secretion of gastric acid by combining with hydrogen,potassium and adenosine triphosphate in parietal cells of stomach.
• React covalently with SH groups of H+K+ATPASE enzyme and inactivate it irreversibly.
• Acid secretion resumes only when new H+K+ATPASE molecules are synthesized.

Therapeutic Uses of Antiulcer Drugs:

• Promote healing of duodenal 
• Gastric ulcers
• Peptic Ulcers
• Stress ulcer
• GERD
• Aspiration Pneumonia
• Zollinger Ellison Syndrome
• Bleeding peptic ulcer

Adverse effects of Antiulcers:

• Nausea                                       
• Constipation                             
• Headache                                   
• Diarrhea                                      
• Depression                                
• Joint Pain                                    
• Cramping                                    
• Hives                                            
• Leucopenia
• Rashes
• Hepatic Dysfunction
• Hepatic Dysfunction
• Erectile Dysfunction 
• Abdominal pain

Drug Interaction:

Antiulcer drugs inhibits oxidation of certain drugs, diazepam, phenytoin and warfarin.