Antiulcer drugs

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Antiulcer drugs
A peptic ulcer is a circumscribed lesion that develops in the mucous membranes of the lower esophagus, stomach, duodenum, or jejunum.

Counting causes

The five major causes of peptic ulcers are:

• 
  bacterial infection with Helicobacter pylori
• 
  the use of nonsteroidal anti-inflammatory drugs (NSAIDs)
• 
  hypersecretory states such as Zollinger-Ellison syndrome (a condition in which excessive secretion of gastric acid causes peptic ulcers)
• 
  cigarette smoking, which causes hypersecretion and impairs ulcer healing
• 
  a genetic predisposition, which accounts for 20% to 50% of peptic ulcers.

Balancing act
Peptic ulcer drugs are aimed at either eradicating H. pylori or restoring the balance between acid and pepsin secretions and the GI mucosal defense. These drugs include:

• 
  systemic antibiotics
• 
  antacids
• 
  Histamine-2 (H2) receptor antagonists
• 
  proton pump inhibitors
• 
  other peptic ulcer drugs, such as misoprostol and sucralfate.

Systemic antibiotics
H. pylori is a gram-negative bacterium that’s thought to be a major causative factor in the formation of peptic ulcers and gastritis (inflammation of the stomach lining). Eradication of the bacteria helps to heal ulcers and decrease their recurrence.

Teamwork is a must
Successful treatment involves the use of two or more antibiotics in combination with other drugs such as acid suppressants. Systemic antibiotics used to treat H. pylori include:

• 
  amoxicillin
• 
  clarithromycin
• 
  metronidazole
• 
  tetracycline.

Pharmacokinetics (how drugs circulate)
Systemic antibiotics are variably absorbed from the GI tract.

Dairy delay
Food, especially dairy products, decreases the absorption of tetracycline but doesn’t significantly delay the absorption of the other antibiotics.

Distribution and excretion
All of these antibiotics are distributed widely and are excreted primarily in urine.

Pharmacodynamics (how drugs act)
Antibiotics act by treating the H. pylori infection. They’re usually combined with an H2-receptor antagonist or a proton pump cheap cialis to decrease stomach acid and further promote healing.

Pharmacotherapeutics (how drugs are used)
They are indicated for H. pylori eradication to reduce the risk of a duodenal ulcer. For this reason they may be used in conjunction with other medications such as proton pump inhibitors.

Successful strategy
Successful treatment plans use at least two antibiotics and a proton pump inhibitor for 14 days and then use a proton pump inhibitor for 6 more weeks to help reduce acid in patients with a peptic ulcer.

Drug interactions
Tetracycline and metronidazole can interact with many other medications.

• 
  Tetracycline increases digoxin levels.
• 
  Metronidazole and tetracycline increase the risk of bleeding when taken with oral anticoagulants.
• 
  Metronidazole can cause a severe reaction when combined with alcohol. 

Warning!

Adverse reactions to antibiotics
Antibiotics used to improve GI tract function may lead to adverse reactions.

• 
  Metronidazole, clarithromycin, and tetracycline commonly cause mild GI disturbances.
• 
  Clarithromycin and metronidazole may also produce abnormal tastes.
• 
  Amoxicillin may cause diarrhea.

Posted in: Gastrointestinal drugs, Pharmacology