Are you suffering from a fever alongside cold, cough, or flu? Your healthcare provider might prescribe antibiotics for relieving your symptoms. If you are wondering, how long does it take for antibiotics to work? You have come to the right blog; we have your answer along with additional information for help. Read about antibiotics, when they are used, and the risk factors of abuse.


Antibiotics are medicinal drugs that help fight illnesses and infections caused because of bacterial manifestation. They are also termed antibacterial agents due to their effect on bacteria.

The death toll was very high back in the day and was mostly caused by bacterial infections. This incidence was lowered after antibiotics came into existence, the fatality rate decreased multifold.

How Long Do Antibiotics Take To Work?

Antibiotics have no definite time period for working. Every category takes its time to show effect; some may take hours while others may show effect within a few days. The dose and time taken by the drug depend on the severity of infection and the dose used.

Here are 2 scenarios; erythromycin prescribed for systemic infections will start showing results within 2 to 3 days. On the other hand, if used for acne as a topical agent, it may take at least a month.

When antibiotics start working within hours, their effect is visible within a few days. However, alleviating symptoms does not mean that you stop taking it. The reason for this is clearing out the entire bacterial load, any leftovers can result in recurrence of infection.

Antibiotics – Classes

There are many different types of classifications available for antibiotics and most commonly used is based on mechanism of action, mentioned below;


Penicillin was the first-ever antibiotic extracted from the bacteria known as staphylococcus by a scientist namely Alexander Fleming. It is an antibiotic that shows its effect on strep infections, pneumonia, anthrax, etc.
Antibiotics have multiple mechanisms for getting rid of bacteria. Penicillin indirectly breaks the cell wall making it burst. These antibiotics work on peptidoglycans, a mesh structure that strengthens the bacterial cell wall and fills it in after division.


Macrolides are another class that works in patients who are allergic to penicillin. This category is most promising because the stomach tolerates them well and shows reduced side effects. They act on bacteria that adversely affect the respiratory system.
Macrolides are bactericidal, they stop protein biosynthesis essential for its survival.


Tetracyclines show effect for skin, urinary, respiratory, and other body infections, it is the first macrolide.
Tetracycline inhibits the production and translation of essential proteins needed for growth.

Antibiotics and Dosage Forms

Antibiotics are available in various dosage forms to cater to a wide variety of infections of every body part, both internal and external.

  • Tablets
  • Ointment
  • Creams
  • Capsule
  • Syrups or other liquids


If you are still confused about the medications prescribed to you, reach out to us at San Ramon Urgent Care for expert opinion and detailed consultation. Call now at San Ramon Urgent Care – San Ramon 925 361 5959 or Manteca 209 825 5155 or Lathrop 209 983 9000 for details or set up an appointment.

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