Taking Antibiotics
You’ve most likely taken an antibiotic or anti-infective at least once in your lifetime. From treatments for painful strep throat or ear infections as a child, to burning urinary tract infections or itchy skin infections as an adult, antibiotics are one of the most highly utilized and important medication classes we have in medicine.

Understanding the vast world of antibiotics and anti-infectives is no easy task. Anti-infectives are a larger class of many types of drugs that cover a broad range of infections, including antibiotics, antifungals, antiviral, and even protozoal infections.

Examples

Athletes foot: That’s a common fungal infection.
HIV: Antiviral medications are always needed.
Bladder infection: Yes, that may need a common oral antibiotic.
Head lice: A topical anti-parasitic can alleviate the itching.
There is no one type of antibiotic that cures every infection. Antibiotics specifically treat infections caused by bacteria, such as Staph., Strep., or E. coli., and either kill the bacteria (bactericidal) or keep it from reproducing and growing (bacteriostatic). Antibiotics do not work against any viral infection.

When To Use Antibiotics
Antibiotics are specific for the type of bacteria being treated and, in general, cannot be interchanged from one infection to another. When antibiotics are used correctly, they are usually safe with few side effects. Health care providers are able to assess each patient individually to determine the correct antibiotic, dose and length of treatment.

However, as with most drugs, antibiotics can lead to side effects that may range from being a nuisance to serious or life-threatening. In infants and the elderly, in patients with kidney or liver disease, in pregnant or breastfeeding women, and in many other patient groups, antibiotic doses may need to be adjusted based upon the individual patient. Drug interactions can also be common with antibiotics.

When NOT To Use Antibiotics
Antibiotics are not the correct choice for all infections. For example, most sore throats, cough and colds, flu, COVID or acute sinusitis are viral in origin (not bacterial) and do not need an antibiotic. These viral infections are “self-limiting”, meaning that your own immune system will usually kick in and fight the virus off.

Using antibiotics for viral infections can increase the risk for antibiotic resistance. Antibiotic-resistant bacteria cannot be fully inhibited or killed by an antibiotic, even though the antibiotic may have worked effectively before the resistance occurred. This can also lower your options for effective treatments if an antibiotic is needed eventually due to a secondary infection. Using unnecessary antibiotics also puts you at risk for side effects and adds extra cost.

It's important not to share your antibiotic or take medicine that was prescribed for someone else, and don't save an antibiotic to use the next time you get sick. It may not be the right drug for your illness.

To better understand antibiotics, it’s best to break them down into common infections, common antibiotics, and the top antibiotic classes as listed in Drugs.com.

Top 10 List of Common Infections Treated with Antibiotics
Acne
Bronchitis
Conjunctivitis (Pink Eye)
Otitis Media (Ear Infection)
Sexually Transmitted Diseases (STD’s)
Skin or Soft Tissue Infection
Streptococcal Pharyngitis (Strep Throat)
Traveler’s diarrhea
Upper Respiratory Tract Infection
Urinary Tract Infection (UTI)
Top 10 List of Generic Antibiotics
amoxicillin
doxycycline
cephalexin
ciprofloxacin
clindamycin
metronidazole
azithromycin
sulfamethoxazole and trimethoprim
amoxicillin and clavulanate
levofloxacin
Top 10 List of Brand Name Antibiotics
Augmentin
Flagyl, Flagyl ER
Amoxil
Cipro
Keflex
Bactrim, Bactrim DS
Levaquin
Zithromax
Avelox
Cleocin
Top 10 List of Antibiotic Classes (Types of Antibiotics)
Penicillins
Tetracyclines
Cephalosporins
Quinolones
Lincomycins
Macrolides
Sulfonamides
Glycopeptides
Aminoglycosides
Carbapenems
Most antibiotics fall into their individual antibiotic classes. An antibiotic class is a grouping of different drugs that have similar chemical and pharmacologic properties. Their chemical structures may look comparable, and drugs within the same class may kill the same or related bacteria.

However, it is important not to use an antibiotic for an infection unless your doctor specifically prescribes it, even if it's in the same class as another drug you were previously prescribed. Antibiotics are specific for the kind of bacteria they kill. Plus, you would need a full treatment regimen to effectively cure your infection, so don't use or give away leftover antibiotics.