How long do antibiotics take to start working? 

How long do antibiotics take to start working? 

Most antibiotics start to work within a few hours to a few days, depending on the severity of your infection and the antibiotic you’re taking. 

The duration of treatment with most antibiotics is 7 to 14 days and this time period is usually enough to treat your bacterial infection effectively. The time taken by your antibiotic to work also depends on the dosage form you’re taking. Let’s take a look at them (1). 

Antibiotic injections

In the case of antibiotic injections, the drug will start to work almost immediately as it doesn’t have to go through all the processes that a medication goes through when taken by mouth. 

The injection delivers the drug directly into your bloodstream. This is why in severe widespread infections, most doctors opt for antibiotic injections. 

Oral antibiotics (Tablets, Capsules, Suspensions) 

In the case of oral dosage forms, the med first enters your stomach and gets dissolved into the gastric fluid, from where it is absorbed into your blood. 

However, some part of the active drug is lost because of the liver’s first-pass metabolism. Liquid preparations might take less time to work as compared to solid compact tablets. In the case of capsules, the shell is dissolved first and then the drug gets released. 

Topical antibiotics

Antibiotics are also available in the form of topical preparations which are applied right on the site of infection. These formulations first get absorbed into your skin and that’s when they start to provide local symptomatic relief. 

The risk of antibiotic resistance 

As I stated earlier, most antibiotics take 7 to 14 days to treat your infection. However, you may begin to feel better within 3-4 days. 

Some people, once they begin to feel better within 2-3 days, stop taking their antibiotics any further thinking that their infection has subsided, but that is not the case. 

Most antibiotics suppress the growth of bacteria or kill the majority of them in just a few days and your symptoms get better. However, you will need to complete the antibiotic regimen that your doctor has prescribed for complete bacterial eradication. 

If you leave your treatment halfway, the leftover bacteria will begin to multiply and your symptoms will start to get worse again. This is why it’s in your best interest to complete the course of your antibiotic treatment, even if your symptoms get better before that. 

It is also important to stick to your doctor’s recommended dose. Just like skipping your antibiotic can result in therapeutic inefficacy, overdosing on your antibiotic can lead to disturbing side effects. This is why you should stick to the prescribed dose. If you’re concerned about something, please consult your doctor. 

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References

1.-

National Health Services (NHS, London). Antibiotics. [Internet]. [cited 2022 Dec 30]. Available from: https://www.nhs.uk/conditions/antibiotics/.