Antibiotics have changed the way we approach medical treatment today. They can cure infections that could have been fatal just 50 years ago; they are also used to perform surgery, care for wounds, and treat many other chronic diseases we have today. With all of this said, it is easy to forget how to use them. One of the biggest ways in which people are misusing antibiotics is the habit of taking some leftover antibiotic from when they got sick previously without checking with their physician first. 

While it seems like a cost-saving measure and is very easy, there is actually an extremely high chance that taking an old antibiotic will hurt you instead of helping you. Here are some reasons why you should never use an old antibiotic prescription.

Top 10 Reasons Not to Use Leftover Antibiotics

1. Not All Infections Are Bacterial

Antibiotics are designed to kill only bacteria, not viruses, which means they cannot cure viral infections or any type of condition caused by viruses, including cold, flu, sore throat or any form of cough. Using antibiotics to treat these types of illnesses will not shorten the duration of your illness and will not make you feel any better.

When you use the wrong antibiotic to self-treat, you run the risk of masking the real problem and delaying treatment that could help to improve your health status.

2. You May Not Have the Same Illness

Although you may have symptoms that appear to be the same as the symptoms you experienced with a previous illness, this does not mean you have the same type of illness as before. For instance, if you have a sore throat, the cause of your sore throat may be due to a viral infection, allergies, gastroesophageal reflux disease, or a bacterial infection like strep throat.

If you use leftover antibiotics to self-treat your sore throat, you are assuming that you have the same type of infection as you had previously without being positively evaluated by a healthcare professional. Using the wrong antibiotic will not treat the underlying cause of your sore throat symptoms; therefore, you run the risk of aggravating your medical condition.

3. Incorrect Dosage Is Dangerous

Doctors write prescriptions for antibiotics to be taken as directed for a specific period. If you have leftover antibiotics, it may indicate that you did not take them all previously or limited your supply (if you only have a few tablets).

Not completing the number of required doses, or not taking the correct doses, can:

• Do not kill the bacteria completely
• Increase the risk of your infection recurring
• Make it more likely that bacteria will become resistant to antibiotics

Not finishing your course of antibiotic therapy is one of the most important factors that increases your risk of developing antibiotic-resistant bacteria.

4. Antibiotic Resistance Is a Serious Global Threat

Antimicrobial resistance is regarded as a public health issue. It occurs when bacteria become resistant to antibiotics through adaptation, and the evolution of pros and cons of adaptation can coexist with bacteria, allowing them to survive and grow despite antibiotic treatment.

Abuse of antibiotics leads to antibiotic resistance from various elements, including taking at non-prescribed doses, abuse without medical supervision, and incorrect dosing. Over time, antibiotic use and bacterial resistance will make infections hard to treat and increase the risk of complications.

Some possible causes of infection may include:

• Prolonged duration of illness
• Increase in number of visits to hospital emergency departments
• Requirement for newer, stronger, and more expensive medications
•  Increased risk for poor patient outcomes

Using leftover antibiotics increases the prevalence of antimicrobial resistance and contributes to the rapidly growing global problem.

5. Side Effects Can Occur Without Proper Supervision

Side effects commonly occur with antibiotic use. Listed below are some common side effects associated with antibiotics. The most common side effects are: 

• Nausea
• Diarrhea
• Allergies 
• Yeast Infections

Less common side effects are severe allergies to the antibiotic and serious complications associated with the antibiotic (e.g., antibiotic-associated colitis). 

In the case of using prescribed antibiotics to treat an infection, taking leftover antibiotics without professional oversight raises the risk that you may not be aware of potential drug interactions, allergies, or underlying health problems that could increase your risk for developing side effects.

6. You May Delay Proper Treatment

Using leftover antibiotics to treat yourself is only going to relieve your symptoms temporarily. In the process, you will also give yourself a false sense of no longer having an issue while the issue still exists and is worsening.

Some infections require different types of antibiotics or no antibiotics at all. If you don’t get treated.

7. Expired Antibiotics May Not Be Effective

Medication will lose strength with time. Expired antibiotics might not have the same effects as they were intended to have, so you won’t receive all the benefits you should receive. In some cases, medications degrade and may cause side effects.

You should always check the expiration dates for your medications and never assume that the medication you have is still safe and/or effective after its expiration date.

8. Sharing or Reusing Prescriptions Is Unsafe

Prescriptions are written specifically for you. Your weight, age, kidney function, allergies and type of infection would all affect the antibiotic and the dosage that you would have prescribed for you.

Taking the leftover antibiotics from someone else would expose you to the risk of taking antibiotics that are dangerous to you. The antibiotics that someone else was prescribed are for their specific needs and not necessarily yours.

9. It Encourages Poor Medication Habits

Using leftover antibiotics usually means that you did not take all of your prescribed antibiotics as instructed. If you do not finish your antibiotics, bacteria may survive and reproduce. That increases your risk of antibiotic resistance.

Being in the habit of saving and reusing antibiotics can encourage the development of unsafe medication habits, which can have a negative impact on both your health and the health of others.

10. Proper Disposal Is Important

Don’t keep leftover antibiotics (“just in case”) but rather dispose of them correctly with a pharmacy or another program. Safe disposal prevents unintentional ingestion, misuse and contamination of the environment.

Instead, do the Following:

If you don’t feel well:

• See a health care professional to receive an accurate diagnosis. 
• Only take antibiotics that have been prescribed to you.
• Complete the entire course of antibiotics as directed.
• Do not share or reuse antibiotics.

If your symptoms worsen or do not improve while taking antibiotics, contact your healthcare professional for assistance.

Bottom Line

Leftover antibiotics may seem like a simple solution; however, there are many dangers associated with their use. Dangers include improper treatment, longer healing time, bacterial resistance to antibiotics, and side effects.

Antibiotics are an important component of medicine and should be used only as directed. Before you start any antibiotic therapy, please ensure that you get a professional opinion about your problem. This way, you are not only protecting your health but also helping to address the problem many countries face with antibiotic resistance.

Never self-medicate with antibiotics; the best rule to follow is to always speak to a professional.