Antibiotics are drugs that are used in the treatment and prevention of bacterial infections. They may either inhibit the growth of bacteria or kill them outright. Antibiotics vary in their mode of action, effectiveness, and how they are administered. They usually start working very quickly, but they differ in how long they stay in your body, depending on the type of antibiotic, how long you take it, and a few other factors.
In this article, we will go over what antibiotics are used for, types of antibiotics, and how long different types stay in your system.
What Are Antibiotics?
Technically, the term “antibiotic” only refers to substances that come from natural sources such as bacteria and molds, and synthetic antibiotics designed in labs should really be called antibacterial or antimicrobial drugs. However, in everyday usage we think of all drugs that help fight bacteria as antibiotics, no matter how we get them. (Source)
Antibiotics are used to treat infections caused by bacteria, such as strep throat, bacterial pneumonia, ear infections, and urinary tract infections. It’s key to note that antibiotics are not effective against viral infections, which may be treated with a different class of drugs called antivirals. This is why antibiotics don’t work against the common cold, which is a viral rather than bacterial infection. (Source)
Antibiotics stay in your system for anywhere from a few hours to a few days. The exact amount of time will depend not just on the drug and how long you take it, but also on individual factors such as your age and body mass.
Types of Antibiotics
Antibiotics can be characterized and grouped based on their mechanism of action, their spectrum of action (which bacteria they work against), and how they are administered.
Antibiotics: Mechanism of Action
Antibiotics are either bactericidal, meaning they kill bacteria, or bacteriostatic, meaning they keep bacteria from reproducing while the immune system finishes the job. They do this by interfering with:
- building and maintenance of the cell wall
- production of DNA and RNA
- production of proteins needed for cellular function
Antibiotics: Spectrum of Action
Antibiotics can also be classified by their spectrum of action, which is the range of different pathogens they act against.
- Broad-spectrum antibiotics are effective against a wide range of bacteria and are especially useful when the target pathogen hasn’t been identified.
- Narrow-spectrum antibiotics are used to treat infections caused by specific types of bacteria after they’ve been identified.
Broad-spectrum antibiotics may also have off-target effects and kill off microbes of the normal microbiota, especially in the gastrointestinal tract and on the skin. Narrow-spectrum antibiotics are less likely to do this. Through dietary changes, any imbalances in the gut microbiome due to antibiotics use can be managed. Our Care Team at WellTheory can help you to understand and unlock the power of food as medicine. (Source)
Antibiotics: Method of Administration
Along with the different classes of antibiotics, they can also come in various forms. There are multiple ways an antibiotic medication can be administered, including:
- oral administration: taken by the mouth, including tablets, capsules, and liquids
- intravenous administration: injected into a vein, allowing the antibiotic to go directly into the bloodstream
- topical administration: applied to the skin, through creams, lotions, and ointments