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Have you ever wondered why the doctor tells you to finish the entire course of antibiotics when you feel better after two days? Confused about why you didn’t get any antibiotics for your viral illness? We’re here to answer some of the top questions about antibiotics.


June 29, 2020

When it comes to antibiotics, there can be a lot of questions about when they’re prescribed, how long they should be taken for and everything in between. We’re taking a look at some common questions (and their answers!).  

What are Antibiotics and How Do They Work?

Let’s start with the basics here by first addressing what exactly antibiotics are. In short, antibiotics are medications that fight infections caused by bacteria (we’ll get into that a bit more below). They work by either killing the germ by attacking the wall of coating surrounding the bacteria or hindering its ability to multiply and grow by blocking protein production in the bacteria.

When a health care provider deems that an antibiotic is necessary to treat your bacterial infection, there are several they might choose from. After all, antibiotics may be a blanket term for the medication in reference here, but there are different classifications based on each one’s chemical structure. The ones you are probably most familiar with are the class of penicillins, which of course includes penicillin and amoxicillin. Forgive the long, confusing names, but the other classes include macrolides, cephalosporins, fluoroquinolones, beta-lactams, tetracyclines, trimethoprim-sulfamethoxazole, urinary anti-infectives and lincosamides.1 Phew – are you still with us? If so, just know that each of those chemical make-ups work in slightly different ways to ultimately kill the bacteria or keep it from spreading.

woman holding glass of water and antibiotics medicine

Viral vs. Bacterial

It’s important to understand here that not every illness requires prescription medications, like antibiotics. Your health care provider will recommend treatment based on the type of germ – a virus or bacteria – that caused your illness to begin with.

Let’s start with viral infections. Viruses are not complete cells and in order to survive and multiply, they require living hosts such as people, animals or plants. Infections caused by viruses spread systematically throughout your entire body and are in fact very contagious. A couple great examples of viruses are common colds, influenza (the flu) and chickenpox.

All that being said, viral infections are treated by finding ways to manage symptoms with fluids, rest and likely over-the-counter (OTC) medications. There may be some anti-viral medications available to specifically treat some specific viruses, but not all of them.

On the other hand, let’s take a closer look at bacterial illnesses. It’s important to know that bacteria are generally single-celled organisms that can survive on their own without the need of a living host. Most bacteria are actually pretty harmless, but many are known to invade the human body and cause infection. Unlike viruses, while bacteria may spread throughout the body in severe cases, they most commonly stay isolated to one part of the body.

A couple examples of bacterial infections that you’re likely familiar with are strep throat, bacterial pneumonia and urinary tract infections. Similar to viral infections, the treatment method for bacterial infections includes symptom management with fluids, rest and OTC medications.

The main difference here, though, is that antibiotics can be prescribed to treat bacterial infections.

Antibiotics Q&A

Now that we’ve uncovered some great information about what antibiotics are and when they’re prescribed, let’s run through a couple common questions about this confusing topic.

Q: What are natural antibiotics?

A: Great question. When you think about it, antibiotics have been around for centuries and they’re derived of natural sources. So it’s understandable that there would be a number of plant extracts, foods or oils would have antibiotic properties. In fact, one of the most common and oldest-known natural antibiotics is honey. Its high sugar content and low pH level make it a powerful bacteria inhibitor. A couple others that fall on this list are garlic extract and the essential oils of thyme and oregano.2 Before starting or using any of these natural antibiotics, though, it’s important to talk with your health care provider who can help you explore your options and weigh the benefits and risks of each.

Q: Do antibiotics effect other prescriptions or medications?

A: We’ll start out here by saying you should always talk with your health care provider about what medications or prescriptions you’re currently taking – once again, they’ll be able to explore your options and get you on the safest, healthiest road to recovery. That being said, there are some medications that may be affected by your round of antibiotics.

For example, almost all antibiotics can impact the blood thinner Warfarin’s effects by eliminating intestinal bacteria that produces vitamin K. Another scenario you may be familiar with is a certain antibiotics’ impact on contraceptives. The antibiotic Rifampin may reduce plasma estrogen concentrations, which could lead to ineffectiveness of oral contraception during the course of antibiotics.3 It may be advisable to consider another form of birth control while on antibiotics for that reason, but again – chat with your health care provider if you have any concerns about your current birth control method and your antibiotic. Both of these examples are good reminders that while antibiotics can certainly kill or hinder the bacteria that made you temporarily sick, those very antibiotics can also play a bit with your body’s natural processes and production, which may work against the efforts of other medications. Both scenarios are great examples of why you should have candid conversations with your health care provider up front.

Q: Are there any foods or drinks you can’t consume while on antibiotics?

A: While there certainly are some foods and drinks that are beneficial to your body during your bout of antibiotics (like yogurt and high-fiber foods), there are definitely some you should avoid altogether. For instance – did you know that you shouldn’t consume grapefruit of any kind while taking certain antibiotics? It’s true – grapefruit juice can prevent the body from breaking down some antibiotics property, which can be harmful to your health.4

And while you’re taking antibiotics, it’s best to hold off on drinking any alcoholic beverages. Mixing alcohol and certain antibiotics in your system can lead to severe reactions and side effects such as flushing, headache, nausea and rapid heart rate.5 Other dangerous combinations are certain antibiotics and red wine, which can lead to a spike in blood pressure. It’s best just to stay away from your alcohol of choice while your illness runs its course.

As always, it’s a great idea to check with your health care provider or pharmacist about what you can and can’t consume while taking those antibiotics.

Q: What is antibiotic resistance?

A: Because germs continue to grow and find new ways to avoid the effects of antibiotics, this can pose a growing concern for health care providers. According to the Centers for Disease Control and Prevention (CDC), anytime antibiotics are used, they can contribute to resistance. In most cases, though, the benefits of antibiotic intervention usually outweighs the risk of resistance – but when too many antibiotics are used unnecessarily or are misused, the usefulness of that very antibiotic may be less and less during future uses.6 Simply put, when antibiotics aren’t needed or they won’t help you, it’s advised not to take them. Your health care provider can help determine when and if they’re needed.

Q: Why do I need to finish my 10-day antibiotic prescription when I feel better by the second or third day?

A: This one ties a bit into the previous question. If you stop taking your prescribed antibiotic before your doctor advises you to, and you get sick again, the remaining bacteria may have become resistant to the antibiotic you’ve taken. You may feel better after just a few days, and that’s great! But that doesn’t mean the antibiotic has completely finished its difficult job in your body. Give it time to fully work and ward off those germs for future illnesses. Simply put, antibiotics are most effective when they’re taken as your health care provider prescribes – that means don’t skip a dose or stop treatment too soon.7

Antibiotics can be a tough pill to swallow – no pun intended. So the next time a health care provider does (or doesn’t) prescribe an antibiotic, you’ll be better equipped with the knowledge you need to get you through your illness and back on your feet to pursue a healthy, happy life. 


1 CDC: Antibiotic Class Definitions. Accessed April 6, 2020.

2 Oregano Essential Oils. Accessed April 8, 2020.

3 Contemporary Clinic: Identifying Important Antibiotic Drug Interactions. Accessed April 6, 2020.

4 The Effects of Grapefruit Juice. Accessed April 8, 2020.

5 Mayo Clinic: What Are The Effects of Drinking Alcohol While Taking Antibiotics? Accessed April 6, 2020.

6 CDC: Antibiotic Prescribing and Use in Doctor’s Offices. Accessed April 6, 2020.

7 FDA: Combating Antibiotic Resistance. Accessed April 6, 2020.

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