Do Antibiotics Make You Tired?

If you have a bacterial infection then you may be prescribed antibiotics by your doctor. These are very common drugs that kill bacteria or stop it in its tracks. However, just like any other type of medication, antibiotics may come with certain side effects.

Generally speaking, they’re not harmful. However, there are some types of antibiotic medications that can cause fatigue or sleepiness. This is considered to be a rare side effect and one that should be taken seriously. 

For anyone taking antibiotics, understanding the side effects is very important. If you notice anything unusual then you should contact your doctor immediately. However, you should never stop taking medication without orders from your doctor.

What Are Antibiotics? – A Background

Antibiotics include a range of medications which are designed to treat a bacterial infection. This might include respiratory tract infections like pneumonia, skin infections and even sepsis. In some cases, you may be given antibiotics as a preventative measure; this is something that often happens before surgery.

However, while antibiotics have indeed saved the lives of many people, they aren’t without their problems. For starters, there are a lot of associated side effects, which is that case with almost any medication. Moveover, there is some evidence to suggest that antibiotics, when taken continuously, could reduce your life expectancy.

In the human body, bacteria are always present and it’s perfectly normal to have a certain number of bacteria. However, these bacteria can multiply and this is when our immune systems will try to fight them. But sometimes our bodies just haven’t got what it takes to fight the harmful bacteria and we need the backup of antibiotics.

These medications prevent the bacteria from further multiplying and also kill existing bacteria. One of the most well known types of antibiotic is penicillin which attacks the cell wall of the bacteria, therefore destroying it.

A lot of people head to their GP demanding to be given antibiotics even in the case where they’re dealing with a viral infection. It’s important to be aware that antibiotics are not designed to be effective against viruses, for example COVID 19. However, you may be offered antibiotics if you develop a bacterial infection as a result of a virus but the medication will only work against the bacteria. 

While antibiotics are now a common feature in modern medicine, they’ve only been around for about a century. It was Alexander Fleming who discovered antibiotics back in 1928; this was penicillin and his discovery was a total accident.

When Fleming first discovered penicillin, he was able to treat a range of infections that were rife at the time. In most cases, people that contracted things like bacterial meningitis, pneumococcal pneumonia and bacterial endocarditis would end up being fatalities. But with the discovery of this wonder drug, those all become things that a human could survive.

Today, we have a huge range of different antibiotic medications that are all used for various illnesses. What’s fascinating is that antibiotics are still being invented today and can come in many forms such as tablets, lotions, syrups and many others. It’s also possible to administer antibiotics intravenously.

One of the reasons that doctors favour these drugs is that they work so quickly. In many cases, a patient can take their first dose of medication and the initial results may be seen within a few hours. That said, we have to be careful when administering antibiotics as some of the side effects are less than desirable which is why doctors no longer hand them out like sweets.

Is Sleepiness One Of The Side Effects Of Antibiotics?

Antibiotics come with a range of side effects. Some of the most common can include digestive issues like vomiting, nausea and diarrhoea. Other patients will experience headaches or may have an allergic reaction to the medication. Fungal infections and mental health issues such as anxiety and depression are not uncommon in those taking antibiotics.

In some cases, antibiotics may make you feel fatigued. This is not a common side effect. In fact, it’s pretty rare and should be something that is taken seriously. 

The reason that some antibiotic drugs make you feel tired is yet unknown. However, there are some scientists that suggest it is because the body changes how it absorbs nutrients and there is a risk of dehydration due to changes in the digestive biome when taking these medications. 

It’s important to keep in mind that not all antibiotics come with a risk of tiredness. If you’re at all unsure of the potential side effects of the medication you’re being prescribed, speak to your doctor or pharmacist.

What Are The Types of Antibiotics That Can Make You Tired?

Certain types of antibiotics come with the potential of feeling fatigued. Again, I have to stress that this is a rare side effect and should be reported to your doctor. If you’re taking any of the following types of antibiotics, be aware that fatigue is a possibility. 


Amoxicillin is a type of penicillin that is often used to treat things like UTIs, bronchitis and pneumonia. The reason that this particular type of antibiotic may make you feel tired is because of the effect that it has on your nervous system. 

While many people will feel sleepy when they take amoxicillin, it is not normal to feel unusually weak or faint. If you are finding it difficult to stay awake during the day then this should immediately be discussed with your doctor. It doesn’t necessarily mean that you will not be able to treat your condition, you just may need to try an alternative medication such as sulfamethoxazole. 


Azithromycin is a very common type of antibiotic that is used for skin infections, infections of the eyes and ears and respiratory infections. You may also be prescribed this type of antibiotics if you have contracted a sexually trasmitted infection. However, tiredness is a widely reported side effect that may mean you need to use a different medication like clarithromycin. 


Where patients are suffering with bone, prostate or skin infections, ciprofloxacin is a very commonly prescribed type of antibiotic.  However, as with the previous types we have discussed, this one can cause extreme fatigue. 

In addition to this, you may experience being less alert than normal and feeling dizzy. While these are symptoms that should be discussed with your doctor, they’re not typically anything to worry about. 

For people who are allergic to penicillin, ciprofloxacin is one of the most common alternatives. 

What Should You Do If You Feel Tired When Taking Antibiotics?

When your doctor prescribes you antibiotics, he or she will discuss any possible side effects and will be able to answer any questions or concerns you may have. However, if upon taking the medication, you notice that you feel unusually drowsy, this is something you should discuss further with your healthcare provider. 

Your doctor may be able to offer an alternative medication or alter your dosage. However, you should also make sure that you avoid taking any other medications alongside the antibiotics, especially those that list drowsiness as a side effect. The only exception to this would be if your doctor gives you the go-ahead. 

It’s also advisable to avoid taking any other substances that could exacerbate your tiredness such as alcohol or recreational drugs. If you are feeling drowsy, you should also avoid activities such as driving.

Where you have spoken with your doctor and made changes to your medication plan, you should notice that the fatigue subsides. However, if it does not then it’s essential to go back to your GP and discuss further action.


Antibiotics are very effective drugs that are used to treat a multitude of bacterial infections. However, as with all medications, there is a risk of certain side effects. With most antibiotics, sleepiness is not considered a common side effect. But there are some types of antibiotics where it can be an issue. If you are taking these and start to feel fatigued, you should speak to your doctor to look at alternative treatments.