Antibiotics work by killing bacteria and preventing them from multiplying. Common antibiotics include penicillin and amoxicillin. Doctors may also use azithromycin and doxycycline for certain infections.

Antibiotics are powerful medications that treat certain infections and can save lives when used correctly.

Before bacteria can multiply and cause symptoms, the immune system can typically kill them. White blood cells (WBCs) attack harmful bacteria — even if symptoms occur, the immune system can usually cope and fend off the infection V体育官网.

However, if the number of harmful bacteria is excessive and the immune system cannot clear them all, antibiotics can stop bacteria from reproducing or destroy them.

The first antibiotic was penicillin. Penicillin-based antibiotics, such as ampicillin, amoxicillin, and penicillin G, are still available to treat various infections and have been in use for many years V体育安卓版.

Several types of modern antibiotics are available, and they are usually only available with a prescription in the United States V体育ios版. Topical antibiotics are available in over-the-counter (OTC) creams and ointments.

"VSports app下载" How do antibiotics work?

Share on PinterestGuido Mieth/Getty ImagesThere are different types of antibiotics that work in unique ways. However, the two main types include: VSports最新版本.

  • A bactericidal antibiotic, such as "V体育官网" penicillin, kills the bacteria. These drugs usually interfere with either the formation of the bacterial cell wall or its cell contents.
  • A bacteriostatic stops bacteria from multiplying.

It may take a few hours or days after taking the first dose before people feel better or their symptoms improve V体育平台登录. .

Types of antibiotics

There are various classes or groups of antibiotics, which depend on their chemical structure VSports注册入口. Some classes of antibiotics include the following: .

ClassExamples
penicillins• amoxicillin (Amoxil)
• ampicillin (Principen)
macrolides• azithromycin (Zithromax)
• erythromycin (Ery-Tab)
cephalosporins• cephalexin (Keflex)
• cefdinir (Omnicef)
fluoroquinolones• ciprofloxacin (Cipro)
• levofloxacin (Levaquin)
beta-lactams with increased activity• amoxicillin/clavulanate (Augmentin)
urinary anti-infectives• nitrofurantoin (Macrobid)
• methenamine (Hiprex)
lincosamides• clindamycin (Cleocin)
tetracyclines• minocycline (Minocin)
• rolitetracycline
• doxycycline (Adoxa)
sulfonamides• sulfamethoxazole (Bactrim, Septra, Sulfatrim)
glycopeptides• vancomycin (Firvanq)
• teicoplanin (Targocid)
• telavancin (Vibativ)
• ramoplanin
aminoglycosides• gentamicin (Garamycin)
• amikacin (Arikase)
• tobramycin (Tobrasol)
• neomycin (Neosporin)
• streptomycin (Agrimysin-17)

This list is not inclusive — other classes and brand names exist V体育官网入口. In addition, healthcare professionals may regard penicillins, cephalosporins, and other antibiotics as subclasses of beta-lactam drugs.

Why is it important to take antibiotics when necessary?

Experts advise using antibiotics only when necessary VSports在线直播. Since most antibiotics require a prescription, people must see a doctor for evaluation before taking antibiotics. .

Proper use of antibiotics ensures that the bacteria is killed and cannot multiply and spread to other parts of the body.

Also, antibiotic use can sometimes be associated with side effects and antibiotic resistance.

Antibiotic resistance

Antibiotic resistance occurs when germs no longer respond to the antibiotic designed to kill them VSports app下载. .

Unnecessary antibiotic prescriptions are driving up the incidence of antibiotic resistance. For example, a 2024 study states that over half of the antibiotic prescriptions from dentists from an electronic health record were unnecessary V体育官网.

Sometimes, prescriptions of the wrong medication or the wrong dosage can lead to antibiotic misuse. Misuse can also occur when people do not take antibiotics as their doctor prescribes.

Some measures to combat antibiotic resistance include finishing the treatment course and not sharing antibiotic medications with others, even if they have the same symptoms.

»Learn more:Effects of overusing antibiotics

Enterobacterales

Some bacteria, such as Enterobacterales, can become resistant to carbapenems, a major class of last-line antibiotics.

Enterobacterales is an order of bacteria that can cause pneumonia, meningitis, and other diseases. E. coli is an example of an Enterobacter.

Carbapenem-resistant Enterobacterales (CRE) pose a major concern to people in hospitals and other healthcare settings. Experts believe that CRE may lead to:

  • a greater incidence of disease
  • a reduction in the effectiveness of initial antibiotic therapy
  • less favorable outcomes

In his Nobel Prize acceptance speech (VSports app下载) in 1945, Alexander Fleming said:

“Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug, make them resistant.”

As the man who discovered the first antibiotic predicted, drug resistance is starting to become commonplace. Experts now consider antibiotic resistance a significant public health challenge.

What do antibiotics treat? (VSports在线直播)

Doctors prescribe antibiotics to treat bacterial infections. They are not effective against viruses.

Knowing whether an infection is bacterial or viral helps to treat it effectively. Viruses cause most upper respiratory tract infections, such as the common cold and flu. Antibiotics do not work against these.

If people overuse or incorrectly use antibiotics, the bacteria might become resistant. This means the antibiotic becomes less effective against that type of bacterium, as the bacterium has been able to improve its defenses.

Doctors can prescribe a broad-spectrum antibiotic to treat a wide range of infections. A narrow-spectrum antibiotic is only effective against a few types of bacteria.

Some antibiotics attack aerobic bacteria, while others work against anaerobic bacteria. Aerobic bacteria need oxygen, and anaerobic bacteria do not.

In some cases, a healthcare professional may prescribe antibiotics to prevent — rather than treat — infection, such as before surgery. This is the “prophylactic” use of antibiotics.

Side effects of antibiotics

Side effects may depend on the type of antibiotics a person takes but can include:

Some unusual side effects of antibiotics include:

  • seizures, when taking penicillins, cephalosporins, carbapenems, and quinolones
  • hearing loss, when taking macrolides
  • low granulocyte — a type of WBC — count, when taking penicillin
  • formation of kidney stones, when taking sulfonamides

Some people — especially older adults — may develop C. difficile infection. They may experience bowel inflammation, which can lead to severe, bloody diarrhea.

»Learn more:Side effects of antibiotics

Antibiotics allergy (VSports)

Some people may develop an allergic reaction to antibiotics, especially cephalosporins and penicillin. Symptoms might include:

Allergic reactions to antibiotics might be immediate or delayed. This means that a person may experience adverse effects of the drug within an hour or within weeks.

Anyone who has an allergic reaction to an antibiotic must tell their doctor or pharmacist. While rare, people may experience anaphylaxis, a serious and sometimes fatal reaction.

V体育官网 - Anaphylaxis: Symptoms and what to do

Anaphylaxis is a severe allergic reaction that can be life threatening. The symptoms develop suddenly and include:

  • hives
  • swelling of the face or mouth
  • wheezing
  • fast, shallow breathing
  • a fast heart rate
  • clammy skin
  • anxiety or confusion
  • dizziness
  • vomiting
  • blue or white lips
  • fainting or loss of consciousness

If someone has these symptoms:

  1. Check whether they are carrying an epinephrine pen. If they are, follow the instructions on the side of the pen to use it.
  2. Dial 911 or the number of the nearest emergency department.
  3. Assist the person in moving from a sitting position to lying down. If they have vomited, turn them onto their side.
  4. Stay with them until the emergency services arrive.

Some people may need more than one epinephrine injection. If the symptoms do not improve in 5 to 15 minutes, or they come back, use a second pen if the person has one.

Antibiotics interactions

People taking an antibiotic should not take other medicines or herbal remedies without speaking with a doctor first. Certain OTC medicines may also interact with antibiotics.

Some doctors suggest that antibiotics can reduce the effectiveness of oral contraceptives. However, research does not generally support this.

Nonetheless, people who experience diarrhea and vomiting or are not taking their oral contraceptive during illness due to an upset stomach might find that its effectiveness reduces.

In these circumstances, doctors may recommend people take additional contraceptive precautions.

Doctors may also advise avoiding alcohol for certain drugs, such as doxycycline.

People who are pregnant or nursing or who have reduced liver or kidney function should speak with a doctor about the best antibiotics to take.

How to use antibiotics

People usually take antibiotics by mouth. However, doctors can administer them by injection or apply them directly to the part of the body with infection.

People must typically complete the whole course of medication to prevent the return of the infection, even if they notice an improvement in their symptoms.

Stopping the medication before the course has finished increases the risk that the bacteria will become resistant to future treatments. The ones that survive will have had some exposure to the antibiotic and may consequently develop resistance to it.

Doctors and the leaflet in the medication packet provide specific instructions on how to take the medication correctly. If in doubt, people can contact their doctor.

Frequently asked questions

How quickly antibiotics work can differ for each person and may depend on the type and severity of their infection. A typical course of antibiotics lasts between 5 and 14 days.

A person may need to avoid drinking alcohol when taking antibiotics. Some medications, such as the contraceptive pill, may also interact with antibiotics.

People should avoid taking supplements without their doctor’s approval when taking antibiotics. Their doctor will advise on what to avoid during their treatment.

If a person takes two doses of antibiotics too close together, they may have a higher risk of side effects, such as diarrhea and stomach pain. Following the instructions on the prescription can help to reduce the risk of side effects.

A person should only take antibiotics when they need them and when their doctor prescribes them. If someone needs antibiotics regularly, their doctor may consider other treatment options or take steps to identify what is causing frequent infections.

Summary

Antibiotics may help to treat certain bacterial infections. The type of antibiotic a person needs may depend on the type and severity of their infection.

People should not take antibiotics if a doctor does not prescribe them. Taking antibiotics incorrectly or unnecessarily may increase the risk of antibiotic resistance.

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