Systemic antibiotics

Systemic antibiotics

H. pylori is a gram-negative bacterium that’s thought to be a ma-jor 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. Sys-temic 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 tetra-cycline but doesn’t significantly delay the absorption of the other antibiotics.

Distribution and excretion

All of these antibiotics are distributed widely and are excreted pri-marily 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 in-hibitor 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 pro-ton pump inhibitor for 14 days and then use a proton pump in-hibitor for 6 more weeks to help reduce acid in patients with a peptic ulcer.

Drug interactions

§    Tetracycline and metronidazole can interact with many other med-ications.

§    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. (See Adverse reactions to antibiotics.)