Antibiotic treatment: what works, when to use it, and how to avoid harm

Antibiotics save lives, but they’re not a cure-all. Using them at the wrong time—or the wrong way—can make infections worse later by breeding resistant bacteria. Here you’ll get straight talk on when antibiotics help, common choices you’ll see, and clear steps to use them safely.

When you need antibiotics (and when you don’t)

If you have a bacterial infection—like strep throat, a urinary tract infection, or certain skin infections—antibiotics can be the right choice. Viral illnesses such as colds, most sore throats, and bronchitis usually don’t need antibiotics. If your doctor suspects a bacterial cause, they may start treatment right away or order a culture (a lab test) to pick the best drug. For serious infections, cultures and sensitivity testing matter a lot: they tell which antibiotic will work best.

Watch for these red flags that mean see a doctor fast: high fever, spreading redness or swelling, trouble breathing, severe pain, or symptoms that get worse after 48–72 hours on treatment. If symptoms don’t improve in a couple of days, call your provider—sometimes the antibiotic needs to change.

Common antibiotics, side effects, and practical tips

Some frequently used drugs you’ll hear about: amoxicillin (often for ear, sinus, and throat infections), azithromycin or clarithromycin (macrolides for respiratory infections), doxycycline (a tetracycline used for acne and tick-borne illness), metronidazole (Flagyl) for certain gut and dental infections, and trimethoprim-sulfamethoxazole (Bactrim) for UTIs and skin infections. Each one has specific uses and common side effects—stomach upset, yeast infections, or sun sensitivity among them.

Simple rules that cut risk: take the dose exactly as prescribed, finish the course unless your doctor says otherwise, don’t use leftover pills, and never share antibiotics. Tell your provider about allergies (especially to penicillin), pregnancy, and other meds you take—some antibiotics interact with blood thinners, birth control, or antacids.

Metronidazole and tinidazole can cause severe nausea with alcohol—avoid drinking while on these drugs and for at least 48 hours after. If you get severe diarrhea, bloody stools, or a widespread rash, stop the medication and seek medical care right away—these can be signs of a serious reaction or C. difficile infection.

Want to reduce side effects? Ask about taking probiotics during and after a course to help your gut, and follow instructions about taking with food if that reduces stomach upset. Buying antibiotics online? Only use licensed pharmacies and a valid prescription—there’s real risk from counterfeit drugs.

Antibiotics are powerful tools when used correctly. Ask questions, keep notes on what you take and how you react, and stay in touch with your clinician if things don’t improve. That’s the fastest way to get better and help keep antibiotics effective for everyone.