Antibiotics are a special class of medications that specifically target, weaken, and kill bacteria. They're one of the best tools that modern medicine has to fight bacterial infections, and they're also an important tool for COPD treatment.

Unfortunately, people with COPD get respiratory infections much more easily and more often than people with healthy lungs. Lung infections also tend to be more severe in people with COPD because they worsen already-dangerous breathing problems and elevate the risk for severe respiratory complications.

Because of this, antibiotics are a regular and familiar part of many COPD patients' treatment routines. They're used to treat lung infections like pneumonia, to manage COPD exacerbations, and even to prevent future infections and exacerbations before they occur.

That's why, in this post, we're going to tell you all about antibiotics and the role they play in COPD treatment. We'll explain how antibiotics work, how they can improve exacerbations, and discuss the various uses and benefits that antibiotics can for managing COPD.

We'll also discuss how to take antibiotics responsibly and look at some of major risks and concerns that come with frequent antibiotic use among people with COPD. Our goal is to help you better understand your COPD medications and better picture how antibiotics fit into COPD treatment as a whole.

If you'd like to learn more about other COPD medication and how they work, you can find all kinds of helpful information in our other medication guides posted to our blog's Respiratory Resource Center.

Why are People with COPD Prone to Airway Infections?

People with COPD are more prone than most other people to catching all kinds of illnesses that affect the respiratory system. This includes common viruses like the cold and flu, but also more serious lung infections like pneumonia.

At the same time that COPD patients are more likely to catch these illnesses, they are also more vulnerable to serious and life-threatening symptoms if they get sick. Because lungs affected by COPD already struggle to function effectively, they are unable to compensate adequately when a respiratory illness comes along and impairs them even more.

In fact, respiratory illnesses and infections are the main cause of COPD exacerbations, which are days-to-weeks-long episodes where COPD-related breathing problems and other symptoms get worse. Although exacerbations are sometimes mild, moderate exacerbations often require hospitalizations, and severe exacerbations can cause life-threatening breathing problems and permanent lung function decline.

Even a mild cold can cause an exacerbation, but the biggest danger often comes from the risk of secondary respiratory infections. Secondary infections happen when the respiratory system has been so weakened and overwhelmed with the first illness that it makes it significantly easier for a second illness—e.g. a bacterial illness like pneumonia—to evade the body's defense systems and start another infection.

This vulnerability is, in large part, a direct result of the disease causing damage to important disease defense mechanisms in the lungs.

One of these defense mechanisms is mucus, in particular the movement of mucus up and out of the airways. This process traps and physically removes pathogens (like viruses and bacteria) that make it into the lungs.

Unfortunately, people with COPD have narrowed, blocked-up airways that make it more difficult to expel this mucus by coughing. Their mucus also tends to be thick, sticky, and more likely to cling to airway walls than healthy mucus, which is thinner, more fluid, and moves more easily out of the lungs.

Additionally, lung damage and inflammation caused by COPD significantly hinders the function of cilia, which are important hair-like structures covering the inner walls of your airways. Healthy cilia move together in coordinated, rythmic beats, a motion that pushes mucus up and out of the lungs to get expelled.

In airways affected by COPD, many of these cilia become paralyzed so that they are no longer able to effectively move mucus out of the respiratory system. This causes mucus to stay trapped within the lungs and airways where it not only obstructs airflow, but also allows pathogens to continue growing and multiplying inside the lungs.

Because of this, people with COPD have a higher chance of getting sick from any viruses, bacteria, and other pathogens that make it into their lungs and airways. It also makes them more prone to secondary respiratory infections, as the lungs' natural defense mechanisms are further impaired by the increase in COPD symptoms.

It's also important to mention bacterial colonization, a phenomenon where some people with COPD always have a small amount of infectious bacteria in their lungs. These bacteria are not as numerous as they are during an active infection, and they usually don't cause any symptoms or actual infections most of the time.

However, colonized bacteria still have the potential to multiply out of control and trigger illness and exacerbation. In fact, research shows that COPD patients with bacterial colonization have more frequent and more severe COPD exacerbations.

When Does Someone With COPD Need to Take Antibiotics?

In general, you usually only need to take antibiotics when you have an exacerbation caused by a bacterial infection. However, since it's difficult to know the cause of an exacerbation for sure, your doctor will likely prescribe you antibiotics anytime you have an exacerbation that seems likely to have a bacterial cause.

Some doctors prescribe antibiotics for people with COPD as soon as an exacerbation starts, even when the patient doesn't have a verified infection yet. This helps stop any current infection in its tracks while also reducing the chances of a secondary respiratory infection popping up later.

In this way, the benefits of taking antibiotics during an exacerbation include reducing symptoms caused by bacterial infections and preventing more serious complications that could arise from secondary infections (even the original cause of the exacerbation is a virus). This can reduce the length of an exacerbation and increase your chances to make a full and quick recovery.

Some COPD patients take antibiotics on a regular basis, even when they're not sick or exacerbating, to help prevent future COPD exacerbations. However, this type of preventative treatment is usually reserved for COPD patients with an especially high risk for infection, such as those who are hospitalized and those who have bacterial colonization in their lungs.

How Do Antibiotics Work?

One way that antibiotics treat and prevent infections is by directly killing bacteria, usually by targeting and destroying the bacteria's protective outer walls. They can also inhibit bacteria in other ways, including by interfering with their metabolism or making them unable to reproduce.

Here are some of the main methods antibiotics use to fight bacteria:

• They can injure the bacteria's outer cell wall, which causes the bacteria to burst open and die.
• They can prevent the bacteria from absorbing nutrients, which stops them from growing and multiplying (giving your immune system the upper hand in the fight).
• They can prevent bacteria from making copies of its DNA, which stops them from multiplying.

There are many different types of antibiotics, and each works in a slightly different way. Different antibiotics also have different strengths and weaknesses against different types of infections.

Some antibiotics are very specialized and only work against a few different types of bacteria, while others—known as broad spectrum antibiotics—are effective against a much wider range of bacteria types. Which antibiotic works best for a particular kind infection depends on a variety of different factors that only your doctor can know for sure.

Here are some of the most common types of antibiotics prescribed to COPD infections and exacerbations:

• Antibiotics for mild to moderate exacerbations:
• Doxycycline (Vibramycin)
• Trimethoprim-sulfamethoxazole (Bactrim DS, Septra DS)
• Amoxicillin-clavulanate potassium (Augmentin)
• Clarithromycin (Biaxin)
• Azithromycin (Zithromax)
• Levofloxacin (Levaquin)
• Gatifloxacin (Tequin)
• Moxifloxacin (Avelox)
• Antibiotics for Severe Exacerbations:
• Ceftriaxone (Rocephin)
• Cefotaxime (Claforan)
• Ceftazidime (Fortaz)
• Piperacillin-tazobactam (Zosyn)
• Ticarcillin-clavulanate potassium (Timentin)
• Levofloxacin (Levaquin)
• Gatifloxacin (Tequin)
• Tobramycin (Tobrex)

Most antibiotics work fairly quickly; once you start a course of antibiotics, a large amount of the bacteria that cause the infection get destroyed within a couple of days. Because of this, you might start to feel better after taking just a few doses of the medication.

However, feeling better does not mean that you're cured. Until you finish the full course of antibiotics, there's a good chance that there's still some bacteria remaining, and it doesn't take much to start up the infection all over again.

That's why it's so important to complete your entire course of antibiotics down to the very last dose. As with any medication, you should take your antibiotics exactly as your doctor instructs; that means taking your medication on time, not missing doses, and resisting the temptation to stop taking the medication after your symptoms go away.

Most antibiotic treatments last anywhere from 5 days to two weeks, depending on the type of antibiotic and the type of infection it's prescribed to treat. Once you complete the full course as directed, the infection and the bacteria that caused it should be thoroughly snuffed out (with the exception of “colonized” bacteria in the lungs of some people with COPD).

Sometimes antibiotics are also used as a preventative measure, in which case the antibiotics work in very much the same way. During the time that you're taking the medication, the antibiotics attack invading bacteria as they come, thwarting any potential infection before it has a chance to take hold.

How Antibiotics are Used to Treat COPD

As we've discussed briefly so far, antibiotics are used quite often in COPD treatment, especially when someone with COPD is hospitalized or has a severe exacerbation. We've mentioned their use as a preventative treatment, as well, to prevent exacerbations and infections before they ever occur.

Now, let's take a closer look at each of these different antibiotic treatments to better understand how they're administered and how they work. Then, we'll discuss some of the major risks and side-effects of using antibiotics to treat COPD, and how frequent antibiotic use can contribute to antibiotic-resistant infections.

Treating Bacterial Respiratory Infections

Antibiotics are pretty much always used to treat illnesses caused by bacteria, including respiratory infections like pneumonia that are common in people with COPD. If you develop such an infection, taking antibiotics directly treats the cause and gives you the best chance of recovery.

However, figuring out whether or not a respiratory illness is caused by bacteria is not exactly simple; it can be difficult and expensive to test for the cause of an illnesses that's deep inside the lungs. Because of this, when COPD patients get sick, doctors often have to rely on making educated guesses about whether the exacerbation is more likely caused by a virus or bacteria.

This determination is based on a variety of different factors, including specific symptoms, exacerbation history, and changes in sputum color. In general, you're more likely (but not guaranteed) to have a bacterial infection if you have the following symptoms: a fever, a COPD exacerbation that doesn't improve with time, sputum that is yellow, green, and if your symptoms don't improve or continue to get worse over time.

Sometimes, these signs are enough to show that a bacterial infection is very likely and that antibiotics are needed. In other cases, if your doctor's not sure, he may run additional tests to look for evidence of infection, including chest x-rays and testing for bacteria in your sputum.

Here are some of the most common types of bacteria that cause lung infections in people with COPD:

• Streptococcus pneumoniae
• Haemophilus influenzae
• Moraxella catarrhalis
• Enterobacteriaceae
• Staphylococcus aureus
• Mycoplasma pneumoniae
• Pseudomonas bacteria

Treating COPD Exacerbations

Research shows that majority of COPD exacerbations are caused by respiratory illnesses (either viral or bacterial), with bacterial infections accounting for about half of COPD exacerbations. But without further testing, it's difficult to know whether a particular exacerbation has a viral or bacterial cause.

It's important to emphasize that antibiotics only work against illnesses and infections caused by bacteria; they can't cure anything caused by a virus or a non-bacterial cause. Because of this, doctors will usually only prescribe them to sick patients who show clear signs of a bacterial infection.

However, doctors often make exceptions for people with COPD, who are both more prone to getting respiratory infections and also more prone to developing severe complications if they do. So instead of waiting to confirm that an illness is bacterial (at which point it has already taken hold), some doctors will often prescribe antibiotics at the beginning of an exacerbation “just in case.”

However, this practice is somewhat controversial, and some experts believe that people with COPD should only take antibiotics after an infection is strongly suspected or confirmed. Limiting the frequency of antibiotic use in this way reduces the risk of antibiotic resistance (a phenomenon that we will discuss more in the following sections).

Others believe that it's helpful to prescribe antibiotics for exacerbations more generally, as a precautionary measure. This may be especially effective for patients who have a high likelihood of infection due to risk factors like bacterial colonization or a history of bacterial infections.

Some doctors will even give some patients an extra course of antibiotics to keep at home until the next time they need them, at start of their next COPD exacerbation. This allows patients to start the course as early as possible while avoiding the hassle (and potential delay) of needing to go to the doctor or pharmacy after they get sick.

Studies show that beginning antibiotics soon after the beginning of an exacerbation can have several benefits, including a higher chance for symptom improvement and even a reduced chance of death. However, some patients are more likely to benefit than others; patients who are hospitalized or have moderate to severe exacerbations seem to receive more benefits from antibiotics than those with milder exacerbations.

If your doctor prescribes you preventative antibiotics, it's important to make sure understand exactly how and when to use them, and never use them for any reason other than what your doctor prescribed them for. Make sure you know the correct medication dosage, timing, and any potential risks, and seek out your doctor or pharmacist if you have any questions or concerns.

You should also ask your doctor to write down clear instructions for all your medications in your COPD action plan. This plan should tell you exactly what to do when you notice your symptoms flaring up, including how to recognize an exacerbation, what steps (and medications) you should take when you feel sick, and when you should call your doctor if your symptoms don't improve.

Preventing Exacerbations: Prophylactic Antibiotics

Some doctors use a treatment known as prophylactic antibiotic therapy (also known as long-term, continuous, or intermittent antibiotic therapy), in which COPD patients take antibiotic medications for extended periods of time. Unlike most antibiotic courses, prophylactic antibiotics are meant to be taken even when you're not sick or experiencing an exacerbation.

The main purpose of this treatment is to reduce the risk of future exacerbations by preventing bacteria from getting the chance to multiply and infect the lungs. Of course, prophylactic antibiotic therapy cannot prevent all exacerbations, since many are caused by viral infections like the flu or common cold.

However, by helping to prevent bacterial infections, continuous antibiotics can still reduce the total number of illnesses and exacerbations a COPD patient experiences.

Research on long-term antibiotic treatment (PDF link) confirms that it can be a viable way to prevent exacerbations in people with moderate to severe COPD. Studies show that prophylactic antibiotics can increase the time interval between exacerbations, reduce the overall frequency of exacerbations, and even shorten the length of exacerbations when they do occur.

As we discussed already, however, taking antibiotics for any reason except to treat an existing bacterial infection is controversial in the medical community. Many experts believe that antibiotics should be used as sparingly as possible, since the risk of antibiotic resistance increases the more often they are used.

Because of this, most doctors avoid prescribing antibiotics for prophylactic use except in special cases where a patient shows a particular need for that extra protection. This sometimes includes “frequent exacerbators” that don't respond to other treatments meant to reduce the frequency of exacerbations.

Other COPD patients who might need continuous antibiotics include those with a higher-than-usual risk for infection, such as those with a history of exacerbations caused by bacterial infection. This also includes people who have an “infective phenotype,” meaning they show signs of long-term bacterial colonization in their lungs.

There are several different methods for prescribing prophylactic antibiotics that differ mainly on how the medication doses get spread out. Some patients take antibiotics daily (the continuous method), some take them just a few days out of every week (the intermittent method), while others take breaks for several weeks in between antibiotic treatments that last for several days (the pulsed method).

Benefits and Risks of Antibiotics to Treat COPD

There is no question that antibiotics are effective against many types of bacterial infections as long as the bacteria hasn't developed antibiotic resistance. If you have COPD and develop a respiratory infection for any reason, your doctor will almost certainly prescribe antibiotics to help you get better.

However, the role of preventative antibiotics for COPD patients are mixed, even though research shows that antibiotics can both prevent COPD exacerbations (when taken continuously), and treat COPD exacerbations (when taken soon after one begins). The main topic of dispute is not whether preventative antibiotics work, but whether or not their benefits are worth their risks.

This is a question that, for now, can only be answered on a case-by-case basis. It's up to you and your doctor to decide—based on your disease severity, infection risk, and other personal health factors—if taking continuous or preventative antibiotics is right for you.

One of the main risks of taking antibiotics is antibiotic resistance; this happens when bacteria mutate and become less susceptible to the effects of an antibiotic medication. This is a problem that affects everyone—not just those currently taking antibiotics—which is why antibiotic resistance is such a serious public health concern.

Antibiotic-resistant bacteria cause antibiotic-resistant infections, which can be very difficult to treat and recover from. In severe cases, bacteria can become resistant to multiple types of antibiotics, causing infections that are deadly or impossible to cure.

The more that people use antibiotics in general, the more prevalent antibiotic-resistant bacteria become, which increases everyone's