Amoxicillin

Amoxicillin is a broad-spectrum antibiotic and belongs to the β-lactam antibiotic class of active ingredients. Areas of application include infections of the gastrointestinal tract, urinary and respiratory tracts, ear and skin. With a few exceptions, the spectrum of activity mainly includes gram-positive bacteria. Amoxicillin is available only with prescription as a mono- or combination preparation.

Amoxicillin is most commonly administered in tablet form or as a juice.

Pharmacodynamics

The action of amoxicillin is based on the interference with the cell wall synthesis of bacteria. It binds to certain proteins in their cell wall and prevents certain cross-links from being produced in it. The cell wall subsequently becomes unstable and collapses. Amoxicillin thus inhibits further multiplication of the pathogens, thus helping to combat the infection.

Pharmacokinetics

Amoxicillin has a bioavailability of approximately 60%. This means that 60% of the dose can reach the bloodstream and exert its effect. Plasma protein binding is 17% and the plasma half-life is approximately 61 minutes. Amoxicillin is broken down in the liver and excreted mainly by the kidneys.

Drug Interactions

Dose adjustment may be necessary when taken concomitantly with probenecid because probenecid may accelerate excretion. There may be an increased likelihood of allergic reactions if taken with allopurinol. Concomitant use with tetracyclines may decrease the effectiveness of amoxicillin. Concomitant use with methotrexate may increase side effects.

Mild overdoses with amoxicillin are harmless due to the wide therapeutic range. Symptoms of severe overdose include abdominal pain, acute renal failure, hematuria, diarrhea and vomiting, skin rashes, and dizziness.

Side effects

The most common side effect is diarrhea. The occurrence of nausea with or without vomiting is also possible. Prolonged use or high doses of this antibiotic may possibly affect the intestinal flora. This can lead to sometimes severe infections in the gastrointestinal tract. Infections of the vagina and skin are also more likely due to the disruption of the natural microbiome.