Prescription bottle next to virus with red X overlay indicating medication ineffective

Why Won’t Antibiotics Cure a Viral Infection? Doctor Explains

Antibiotics changed the course of medicine. They save lives daily against infections that used to kill people: pneumonia, urinary tract infections, strep throat. The catch is narrow and absolute. They work on bacteria. Viruses are untouched. So an antibiotic prescribed for a cold or influenza does nothing useful, and it can still do harm.

The Risks of Misuse

Overuse drives resistance. Bacteria adapt fast, and repeated exposure teaches a population how to survive the drug that used to clear it. Those are the organisms we call superbugs. They make ordinary infections harder to treat, and healthy patients aren’t exempt from that. In its 2019 threats report, the CDC counted more than 2.8 million antibiotic-resistant infections a year in the United States and over 35,000 deaths.

Side effects are the nearer problem for most patients. Antibiotics disturb the gut microbiome, and nausea, diarrhea, and abdominal pain follow. Sometimes that disruption opens the door for Clostridioides difficile and a severe colitis.

Yeast overgrowth is common too. Clear out the normal bacterial balance and Candida fills the space, showing up as oral thrush or a vaginal yeast infection. I’ve had patients relieved that their original infection improved, only to be frustrated by new symptoms a week later.

Using Antibiotics Wisely

The goal is correct use, not avoidance. That’s what antibiotic stewardship means in practice.

Step one is deciding whether the infection is even bacterial. A sore throat is usually viral pharyngitis. Fever with swollen tonsils and no cough moves strep up the list, and a rapid strep test settles it rather than leaving it to impression. Ear pain needs a careful look to separate a viral picture from bacterial otitis media.

Prevention cuts the need in the first place. Vaccination, hand hygiene, safe food handling. I keep telling patients that washing hands before eating and after being out in public does more to keep them off antibiotics than anything I prescribe.

When antibiotics are the right answer, they’ve got to be taken as directed. Stopping early, skipping doses, and saving leftovers all undermine the course and feed resistance. Sharing a prescription with a family member is its own category of mistake.

Where This Leaves Us

Antibiotics remain among the most powerful tools in medicine, and they aren’t free. Misuse buys resistant bacteria, gastrointestinal misery, and yeast overgrowth. Careful prescribing, honest patient education, and prevention are what keep these drugs working for the people who will need them next.

Scott Rennie, D.O.

Sources

Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.

Microscopic glowing microbes of various shapes and colors against a dark background

Antibiotic Superbugs CRKP and MRSA: Who Is at Risk?

By Lisa Collier Cool Apr 07, 2011 Misuse of antibiotics has led to a global health threat: the rise of dangerous—or even fatal—superbugs. Methicillin-resistant Staphylococcus aureus (MRSA) is now attacking both patients in hospitals and also in the community and a deadly new multi-drug resistant bacteria called carbapenem-resistant Klebsiella pneumoniae, or CRKP is now in the headlines. Last year, antibiotic resistant infections killed 25,000 people in Europe, the Guardian reports. Unless steps are taken to address this crisis, the cures doctors have counted on to battle bacteria will soon be useless. CRKP has now been reported in 36 US states—and health officials suspect that it may also be triggering infections in the other 14 states where reporting isn’t required. High rates have been found in long-term care facilities in Los Angeles County, where the superbug was previously believed to be rare, according to a study presented earlier this month. CRKP is even scarier than MRSA because the new superbug is resistant to almost all antibiotics, while a few types of antibiotics still work on MRSA. Who’s at risk for superbugs—and what can you do to protect yourself and family members? Here’s a guide to these dangerous bacteria. Understanding different types of bacteria. What is antibiotic resistance? Almost every type of bacteria has evolved and mutated to become less and less responsive to common antibiotics, largely due to overuse of these medications. Because superbugs are resistant to these drugs, they can quickly spread in hospitals and the community, causing infections that are hard or even impossible to cure. Doctors are forced to turn to more expensive and sometimes more toxic drugs of last resort. The problem is that every time antibiotics are used, some bacteria survive, giving rise to dangerous new strains like MRSA and CRKP, the CDC reports. What are CRKP and MRSA? Klebseiella is a common type of gram-negative bacteria that are found in our intestines (where the bugs don’t cause disease). The CRKP strain is resistant to almost all antibiotics, including carbapenems, the so-called “antibiotics of last resort.” MRSA (methacillin-resistant staphylococcus aureus) is a type of bacteria that live on the skin and can burrow deep into the body if someone has cuts or wounds, including those from surgery. Who is at risk? CRKP and MRSA infects patients, usually the elderly—who are already ill and living in long-term healthcare facilities, such as nursing homes. People who are on ventilators, require IVs, or have undergone prolonged treatment with certain antibiotics face the greatest threat of CRKP infection. Healthy people are at very low risk for CRKP. There are 2 types of MRSA, a form that affects hospital patients, with similar risk factors to CRKP, and another even more frightening strain found in communities, attacking people of all ages who have not been in medical facilities, including athletes, weekend warriors who use locker rooms, kids in daycare centers, soldiers, and people who get tattoos. Nearly 500,000 people a year are hospitalized with MRSA. Keeping hospital patients safe. How likely is it to be fatal? In earlier outbreaks, 35 percent of CRKP-infected patients died, Journal of the American Medical Association (JAMA) reported in 2008. The death rate among those affected by the current outbreak isn’t yet known. About 19,000 deaths a year are linked to MRSA in the US and rates of the disease has rise 10-fold, with most infections found in the community. How does it spread? Both MRSA and CRKP are mainly transmitted by person-to-person contact, such as the infected hands of a healthcare provider. They can enter the lungs through a ventilator, causing pneumonia, the bloodstream through an IV catheter, causing bloodstream infection (sepsis), or the urinary tract through a catheter, causing a urinary tract infection. Both can also cause surgical wounds to become infected. MRSA can also be spread in contact with infected items, such as sharing razors, clothing, and sports equipment. These superbugs are not spread through the air. What are the symptoms? Since CRKP presents itself as a variety of illnesses, most commonly pneumonia, meningitis, urinary tract infections, wound (or surgical site) infections and blood infections, symptoms reflect those illnesses, most often pneumonia. MRSA typically causes boils and abscesses that resemble infected bug bites, but can also present as pneumonia or flu-like symptoms. How are superbugs related? The only drug that still works against the CRKP is colistin, a toxic antibiotic that can damage the kidneys. Several drugs, such as vancomycin, may still work against MRSA. What’s the best protection against superbugs? Healthcare providers are prescribing fewer antibiotics, to help prevent CRKP, MRSA and other superbugs from developing resistance to even more antibiotics. The best way to stop bacteria from spreading is simple hygiene. If someone you know is in a nursing home or hospital, make sure doctors and staff wash their hands in front of you. Also wash your own hands frequently, with soap and water or an alcohol-based hand sanitizer, avoid sharing personal items, and shower after using gym equipment. The CDC has reports on Klebsiella bacteria and MRSA, discussing how to prevent their spread and has just issued a new report on preventing bloodstream infections.

Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine

This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.