A Complete Guide to Amoxicillin

Amoxicillin inhibits cell wall synthesis by preventing the formation of peptidoglycan.

Amoxicillin, as an antibiotic, should only be used to fight bacterial infections, such as syphilis or typhoid fever.

However, even today, sometimes due to ignorance, it’s used for viral infections, such as the flu or colds. This incorrect administration can compromise the effectiveness of the drug in subsequent administrations.

What is amoxicillin for?

On some occasions, our immune system is unable to eliminate the bacteria that invade our tissues, resulting in a bacterial infection in our body. In this infection, there’s a rapid multiplication of bacteria together with an inflammation of the affected tissues.

Amoxicillin can be used to treat infections including:

• Acute otitis media: Very common in children and frequently caused by the Streptococcus pneumoniae bacteria. The patient generally suffer from a fever, earache and hearing loss after a few days with a cough and general malaise.
• Acute bacterial sinusitis: This causes inflammation of the mucosa around the sinuses. This bacterial infection shouldn’t be confused with sinusitis caused by the common cold. Therefore, before prescribing amoxicillin, a culture of the nasal discharge is usually performed.
• Streptococcal tonsillitis and pharyngitis, which come with a sore throat and fever. To rule out a viral infection, a pharyngeal exudate is usually removed from the patient that confirms Streptococcus infection.
• Chronic pneumonia and bronchitis, caused by germs sensitive to the antibiotic.
• Acute cystitis: Usually caused by Escherichia coli, and other kidney infections.
• Some dental abscesses or mouth infections.
• Typhoid fever
• Lyme disease
• The eradication of Helycobacter pylori, a bacterium that causes peptic ulcers.

What family does it belong to?

The creation of the first antibiotic was carried out by Alexander Fleming in 1928. In his laboratory he observed how some of his bacterial colonies didn’t reproduce as they were contaminated by the fungus Penicillium notatum.

A few years later, penicillin G, the first penicillin antibiotic, was isolated from the fungus. After this discovery, new derivatives of penicillin appeared, such as amoxicillin and cloxacillin.

How does amoxicillin work?

Most bacteria have a cell wall, which protects them from the outside and prevents their lysis, maintaining osmotic balance. This bacterial wall is made up of amino sugar chains, linked together by peptides, forming a macromolecule known as peptidoglycan or murein.

Amoxicillin works by inhibiting cell wall synthesis by preventing the formation of peptidoglycan. The transpeptidase and carboxypeptidase enzymes, essential to constitute peptidoglycan, are inhibited by said antibiotic. Amoxicillin has a bactericidal action since it frequently causes the lysis of bacteria.

What is its form of administration?

Its resistance to gastric acid makes oral administration possible with a bioavailability of 80%, reaching the highest plasma concentration within an hour and a half. Although it crosses the mammary and placental barrier, it’s compatible with breastfeeding and presents a risk category B in pregnancy.

The drug can be taken with or without food. In children, the most common pharmaceutical form is the extemporaneous suspension, which is prepared with water up to the mark indicated on the label. The dosage varies depending on age, weight, and type of infection, being essential to follow the prescribed dosage regimen.

What are the side effects?

The presence of a beta-lactam ring in the structure of penicillins can cause allergic reactions. Generally, in an allergy to amoxicillin, skin eruptions occur, except in the most serious cases where anaphylactic reactions can manifest.

In some cases, minor gastrointestinal problems such as diarrhea, vomiting or nausea appear. Diarrhea can be caused by an imbalance of the intestinal flora, as part of it is eliminated. To prevent this loss or rebalance the flora again, it’s advisable to take probiotics.

Is there resistance to amoxicillin?

Amoxicillin is a broad-spectrum antibiotic, since it can act against gram-positive and gram-negative bacteria. However, some bacteria can undergo genetic mutations, making them resistant to the drug.

Penicillinase is a bacterial enzyme that destroys the beta-lactam ring. To combat it, clavulanic acid and amoxicillin are often combined. The possibility of developing resistance to an antibiotic increases with its use, therefore, responsible use and prescription of this drug is essential.