Antibiotic Basics: What They Are and When to Use Them

Antibiotics are medicines that kill bacteria or stop them from growing. They don’t work on viruses, so taking them for a cold or flu won’t help. Knowing the difference can save you from unnecessary side effects and keep the drugs effective for real infections.

If you’ve been prescribed an antibiotic, it’s usually because a doctor suspects a bacterial infection like strep throat, urinary tract infection, or pneumonia. The key is to follow the prescription exactly—finish the whole course, even if you feel better early on. Stopping early lets surviving bacteria become tougher.

Common Antibiotic Classes

Antibiotics come in several groups, each targeting different bacteria. Penicillins (like amoxicillin) are often first‑line for ear infections and some skin bugs. Cephalosporins (such as cefalexin) cover a broader range and are used for more serious infections.

Macrolides (azithromycin, clarithromycin) are good for people allergic to penicillin and work well for respiratory infections. Fluoroquinolones (ciprofloxacin, levofloxacin) are powerful but carry higher risk of side effects, so doctors reserve them for tougher cases.

There are also Tetracyclines (doxycycline) used for acne and Lyme disease, and Sulfonamides (trimethoprim‑sulfamethoxazole) effective for certain urinary infections. Each class has its own dosing schedule and potential interactions, so read the label and ask your pharmacist if something sounds unclear.

Staying Safe and Fighting Resistance

Antibiotic resistance happens when bacteria learn to survive drug attacks. Overusing or misusing antibiotics speeds this up. To keep them working, only take them when a doctor says they’re needed, and never share leftovers with friends or family.

Probiotics can help keep your gut happy during a course, but talk to your doctor first. Also, staying up to date on vaccinations (like flu shots) reduces the chance you’ll need antibiotics later.

If you notice side effects—such as severe diarrhea, rash, or unusual tiredness—contact your healthcare provider right away. Sometimes a different antibiotic or a shorter course is the right move.

Lastly, keep a list of any allergies or past reactions and share it with every new prescriber. This simple step prevents accidental prescribing of a drug that could cause a serious reaction.

Bottom line: antibiotics are a powerful tool when used correctly. By understanding what they do, choosing the right type, and following the prescribed plan, you protect yourself and help keep these medicines effective for everyone.