Know What is Antibiotics: How They Work, When to Take Them & More

Antibiotics are one of the greatest discoveries in medical history. These powerful medicines help our body fight infections caused by bacteria and can even save lives when used correctly. But like all medicines, antibiotics should be used with care — taking them at the wrong time or for the wrong reason can cause more harm than good.

In this blog, we’ll explain what antibiotics are, how they work, when to take them, their types, side effects, and how to use them safely.

💊 What Are Antibiotics?

Antibiotics are medicines that kill bacteria or stop them from multiplying. They are not useful for viral infections like colds, flu, or COVID-19. Doctors prescribe them for bacterial infections such as throat infections, pneumonia, urinary tract infections, or skin infections.

The first antibiotic discovered was Penicillin in 1928 by Alexander Fleming. Since then, many different types of antibiotics have been developed, such as Amoxicillin, Azithromycin, Doxycycline, and Ciprofloxacin.

How Do Antibiotics Work?

Antibiotics work in two main ways:

1. Bactericidal antibiotics – These kill bacteria directly by breaking their cell wall.
   • Example: Penicillin and Cephalosporins.
2. Bacteriostatic antibiotics – These stop bacteria from multiplying, allowing the body’s immune system to kill the remaining bacteria.
   • Example: Tetracyclines and Macrolides.

When a person takes antibiotics, it may take a few hours or even a few days to feel better. It’s important to finish the full course, even if you start feeling fine — stopping early may let some bacteria survive and become resistant.

🧬 Types of Antibiotics

There are many classes of antibiotics. Each works differently and is used for specific infections. Some common ones include:

Doctors choose which antibiotic to prescribe depending on the type of bacteria, the site of infection, and the patient’s health condition.

🩺 When Should You Take Antibiotics?

Antibiotics should be taken only when prescribed by a doctor. Many people wrongly believe that antibiotics can cure any infection — but that’s not true.

You should take antibiotics only for bacterial infections, not for viral ones like:

• Common cold
• Flu
• Cough due to allergy
• Most sore throats

If you take antibiotics when you don’t need them, they won’t help — and they can even make bacteria stronger in the future.

⚠️ The Problem of Antibiotic Resistance

Antibiotic resistance is one of the biggest health challenges today. It happens when bacteria change in a way that makes antibiotics stop working against them.

Reasons for resistance include:

• Taking antibiotics without prescription
• Stopping the course too early
• Sharing leftover antibiotics
• Using the wrong dose

When bacteria become resistant, infections become harder to treat. Hospitals may have to use stronger or more expensive medicines that cause more side effects.

💡 Example:
Some bacteria like E. coli have become resistant to strong antibiotics called Carbapenems. These infections are known as CRE (Carbapenem-Resistant Enterobacterales) and can cause serious diseases like pneumonia and meningitis.

As Alexander Fleming (the discoverer of penicillin) once warned, using antibiotics carelessly can make them useless in the future.

🤒 What Do Antibiotics Treat?

Antibiotics treat bacterial infections, such as:

• Strep throat
• Urinary tract infections
• Skin infections
• Ear infections
• Bacterial pneumonia

They do not work for viral infections like:

• Cold
• Flu
• COVID-19
• Viral fever

Sometimes, doctors give antibiotics before surgery to prevent infections. This is called prophylactic use.

Common Side Effects of Antibiotics

While antibiotics help cure infections, they can also cause side effects such as:

• Nausea or vomiting
• Diarrhea
• Stomach pain or bloating
• Loss of appetite
• Yeast infection (Candida overgrowth)

Rare side effects may include:

• Allergic reactions (rashes, swelling, breathing problems)
• Hearing loss (with some antibiotics)
• Kidney problems (with sulfa drugs)
• Severe diarrhea due to C. difficile infection (especially in older adults)

If you notice any severe or unusual symptoms, contact your doctor immediately.

🚨 Antibiotic Allergy and What to Do

Some people are allergic to antibiotics, especially penicillin and cephalosporins. Signs of allergy may include:

• Hives or skin rash
• Swelling of lips or face
• Wheezing or difficulty breathing

In rare cases, an allergy can cause anaphylaxis, a life-threatening reaction that needs emergency medical help.

If you ever had an allergic reaction to an antibiotic, inform your doctor before taking any new medicines.

Antibiotic Interactions

Antibiotics can sometimes interact with other medicines or reduce their effect.

For example:

• Some antibiotics may reduce the effectiveness of birth control pills.
• Alcohol should be avoided with certain antibiotics like doxycycline or metronidazole.
• People with liver or kidney problems should consult a doctor before taking antibiotics.

Never mix antibiotics with herbal supplements or over-the-counter medicines unless your doctor says it’s safe.

How to Use Antibiotics Properly

To make sure antibiotics work safely and effectively, follow these steps:

1. Take the full course — don’t stop even if you feel better.
2. Follow the exact dose and time mentioned by your doctor.
3. Don’t share antibiotics with anyone else.
4. Store them properly — usually in a cool, dry place.
5. Consult your doctor if you miss a dose instead of doubling it.

Antibiotics can be taken by mouth (tablets or syrups), injections, or topical creams for skin infections.

Frequently Asked Questions

1. How fast do antibiotics work?
Most antibiotics start working within 24–48 hours, but you must finish the full course even if you feel better.

2. Can I drink alcohol while on antibiotics?
Avoid alcohol with antibiotics like doxycycline or metronidazole. It may cause nausea or make the medicine less effective.

3. What happens if I skip a dose?
Take it as soon as you remember, but never take two doses together.

4. Can I take antibiotics for fever?
Only if your doctor confirms it’s due to a bacterial infection. Most fevers are viral and don’t need antibiotics.

5. Why shouldn’t I save leftover antibiotics?
Because different infections need different antibiotics and doses. Using old ones may not work and can increase resistance.

Summary

Antibiotics are life-saving medicines that fight bacterial infections — but they must be used wisely. Taking them without a doctor’s advice, skipping doses, or stopping early can make bacteria stronger and harder to treat.

Always follow your doctor’s instructions, finish your course, and never self-medicate. Remember: antibiotics are powerful allies — but only when used responsibly