How can medications be taken safely to avoid drug side effects & drug interactions?

 Author: Vera Ubabuike, MBBS, Freelance Medical Writer

Medical Reviewer: Azuka Chinweokwu Ezeike, MBBS, FWACS, FMCOG, MSc (PH)

Highlights

• Drug side effects and drug interactions are undesirable reactions that can be caused by the use of medicines.
• Every medication can cause side effects, but some of these side effects can be avoided.  
• Some common drug side effects include: stomach upset, mild headaches, rashes and vomiting
• Some substances, when taken with medicines, can increase the chances of having side effects and drug interactions. 
• Some serious side effects or drug interactions may require that the medicine be stopped.

Introduction

Have you ever had side effects when taking your medicines? Does this make you anxious about taking medicines?When your doctor prescribes a medicine, the goal is usually to help you feel better. 

Medicines are very helpful substances used to improve or maintain health. Their benefit can be maximised when they are used correctly. Unfortunately, medicines can also cause some harm. Some side effects and drug interactions can occur when taking medicines. Every medication has the potential to cause side effects [1]. 

Each year, more than one million people in the United States visit the emergency room due to harm caused by a medication. The good news is that you can prevent most drug side effects and interactions by safe use of medicines.

The key is to learn the right way to take medicines to reduce drug side effects and interactions or to avoid those side effects completely, where possible. This article outlines how to take your medicines correctly and ensure that they help to heal you without causing unnecessary harm. 

What are drug side effects and drug interactions?

Drug Side Effects

A drug side effect is an undesirable reaction seen after taking a medicine. Side effects range from minor complaints like stomach upsets to life-threatening ones like a heart attack. They occur differently in each person and are often unpredictable. [2]

Some common side effects include: 

• stomach upset
• vomiting 
• minor rashes
• runny nose
• headaches, etc.

Drug Interactions

A drug interaction is a reaction that occurs when a medicine is taken along with certain substances that change the effect of the medicine in the body. Some such substances are foods, beverages, supplements, or other medicines.

A drug interaction can lead to unusual side effects. It can also cause decreased effectiveness of the medicine or life-threatening reactions. This is dangerous because it can decrease the desired effect of the medication in your body and make your healing process slower. It can also lead to more clinic visits or hospital admissions [3].

Drug interactions can occur between:

• Two or more prescription medicines 
• Prescription and over-the-counter medicines 
• Medicines and herbal drugs
• Medicines and certain foods, e.g., grapefruit, coffee
• Medicines and Alcohol 

Why you may have some drug side effects

Although every medicine has its potential side effects, many side effects are preventable. You can avoid side effects by learning more about medicines and how to use them safely. You should also learn why medicines may cause side effects.

Many side effects and drug interactions are a result of:

• Ignoring the instructions for medications
• Taking the wrong medication
• Taking the wrong dose of your medicine
• Incorrect diagnosis of your illness
• An underlying medical condition, e.g., high blood pressure, liver disease, or kidney disease
• Taking your medicine with other medicines or certain foods
• Taking fake or sub-standard medicines, which may be harmful [3,4].

 Who is more likely to Have Drug Side Effects?

Certain groups of people are more likely to have drug side effects. 

They include:

• Children
• Elderly people
• Pregnant women
• Breastfeeding mothers
• Patients with kidney or liver disease

You should take extra care when giving drugs to these people. They are more likely to have side effects as their bodies break down medicines differently. The elderly are particularly at risk of drug interactions because they are often on multiple medicines.

How to Prevent Drug Side Effects  

Before you begin your medicines

Preventing side effects starts with the prescription. There are some safety measures to take before medicines are prescribed for you.

Some of these measures ensure that you are prescribed the right medicines. They include letting your doctor know about the following: 

• All the symptoms that you are having now, so that the right diagnosis can be made
• Any illness you are currently being treated for
• Any drugs or supplements you are currently taking, and how you take them
• Any drug reactions or allergies you have ever had
• If you are pregnant, planning a pregnancy, or breastfeeding [2]

Following the doctor’s prescription, you should: 

• Ask about the medication – What is it for? When should you take it? Should it be taken on an empty stomach or after a meal?
• Ensure that you buy your medications at a trusted and licensed pharmacy
• Read the pharmacy label and any attached information, which may outline how to take the medicines and common side effects 
• Ask your doctor about any possible side effects or drug interactions associated with the prescribed medicine 

How to Take Medications Correctly to Avoid Drug Side Effects

Here are some ways to stay safe after you have been prescribed medicines. You should:

• Take the drugs exactly as you were told to
• Read the medicine labels to learn more about the medicines
• Take the proper dose of your medicine at the prescribed time
• Avoid taking double doses or missing medicines

You should not:

• Change the dose of your medications by yourself; this must be done by your doctor
• Share your medicines with others or take medicines from others
• Take medicines from previous prescriptions
• Stop your drug suddenly unless your doctor instructs you to [5]

You have greater chances of experiencing side effects if you change the dose of your medication. Stopping your medications without consulting your doctor might be dangerous, especially for medicines used for blood pressure, seizures, and steroid treatments [2]. 

Please note that some drug side effects may still occur even when you take your drugs correctly. Sometimes, the presence of side effects suggests that the medicine is working [1].

How to Prevent Drug Interactions

Foods and substances that affect the breakdown of medicines in the body make you more likely to have drug interactions.Hence, you should be cautious of taking these substances while on your medications. They include:

• Supplements
• Herbal drugs
• Coffee
• Alcohol
• Drugs of abuse 

You can also find out from your doctor any substances that might interact with your drug. Some of your common foods may also cause a drug interaction and reduce the action of your medicines [6]. For example, some antibiotics interact with milk, making it harder for the antibiotics to be absorbed into your body.

What to Do When You Notice Serious Drug Side Effects or Drug Interactions

More serious side effects usually need medical attention, as they may not improve without it. 

Some of these serious side effects are:

• Chest pain
• Fainting
• Unusual bleeding
• Breathing difficulties
• Swollen eyes or lips
• Serious rashes
• persistent vomiting, etc.

If you notice any serious side effects, you should:

• Seek help from a healthcare professional immediately
• Avoid taking any home remedies until you have contacted a healthcare professional
• Report serious side effects to the drug safety authorities in your region

You should also contact your doctor if you have minor side effects that do not improve over time but get worse [2]. 

Safe Storage of Your Drugs

Safe storage of medications plays a role in ensuring safe use of medicines. These are some helpful tips for storing medicines:

• They should be in a cool, dry area, unless you are instructed differently
• Some medicines are stored in the refrigerator
• Check often to ensure your medicines are not expired
• Your medicine should be kept away from children

The Importance of Regular Follow-up

Follow-up visits are very important in ensuring your medicines are safe.  A medication review is usually done during your follow-up visit [1].It would be helpful to keep a medication list that details all the medicines you are taking and how you take them.At your follow-up visits, you can make complaints about any side effects and any drug interactions you have noticed, no matter how small they are. Your doctor will let you know about the side effects and reactions that you should be concerned about. It is also a good time to confirm with your doctor that you have been taking your medications correctly.

Key Take-Home Tips on Avoiding Drug Side Effects

• Avoid self-medication
• Let your doctor know about any medicines you are taking and any illnesses you have
• Follow instructions on the use of your medicines carefully
• Store your medications as you have been told
• Report side effects early 
• Ask questions always and listen to the instructions

Conclusion

Medicines are a major means of treating illnesses. Therefore, it is important to ensure that you take medicines correctly. Safe use of medicines ensures that the full benefit of the medication is obtained and unnecessary side effects are avoided. You should stay informed and remain attentive to the proper use of medicines. Your attention and awareness are all that are needed to keep you safe.

References

1. Allegaert K, Choonara I. All medicines have side effects. Arch Dis Child [homepage on the Internet] 2016 [cited 2026 Feb 13];101(10):951–952. Available from: https://adc.bmj.com/lookup/doi/10.1136/archdischild-2016-311014

2. Coleman JJ, Pontefract SK. Adverse drug reactions. Clinical Medicine [homepage on the Internet] 2016 [cited 2026 Feb 16];16(5):481–485. Available from: https://www.sciencedirect.com/science/article/pii/S1470211824024928

3. Cascorbi I. Drug Interactions—Principles, Examples and Clinical    Consequences. Dtsch Arztebl Int [homepage on the Internet] 2012 [cited 2026 Feb 16];109(33–34):546–556. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3444856/

4. Alomar MJ. Factors affecting the development of adverse drug reactions (Review article). Saudi Pharm J [homepage on the Internet] 2014 [cited 2026 Feb 13];22(2):83–94. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3950535/

5. Kommu S, Carter C, Whitfield P. Adverse Drug Reactions [Homepage on the Internet]. In: StatPearls. Treasure Island (FL): StatPearls Publishing, 2025 [cited 2026 Feb 13]; Available from: http://www.ncbi.nlm.nih.gov/books/NBK599521/

6. Bukowska B, Grzegorowska A, Szczerkowska-Majchrzak E, et al. Hazardous Interactions Between Food, Herbs, and Drugs in the First Stage of Biotransformation: Case Reports of Adverse Drug Interactions in Humans. IJMS [homepage on the Internet] 2025 [cited 2026 Feb 13];26(11):5188. Available from: https://www.mdpi.com/1422-0067/26/11/5188

Disclaimer:
The information provided on this website is for general educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Published February 19, 2026