How to Take Medicine Safely Without Putting Yourself at Risk

Taking medicine on your own may help relieve mild symptoms, but incorrect use can lead to side effects, overdose, or drug interactions. Learn how to use medicines safely and when to consult a doctor or pharmacist.

However, “available without a prescription” does not mean “risk-free.” Every medicine can cause side effects, allergic reactions, or interactions with other medicines, food, supplements, herbal products, or alcohol. Taking the wrong dose, using the same active ingredient repeatedly without realizing it, or using medicine despite having certain underlying health conditions can be harmful.

Therefore, taking medicine safely is not only about choosing a medicine that matches your symptoms. It is also important to know what the medicine contains, how to take it, what precautions to follow, and when to stop self-medicating and consult a healthcare professional.

Self-medication means using medicine to relieve or treat symptoms without being assessed by a doctor for that specific episode. This may include buying medicine from a pharmacy, using household medicines, or taking leftover medicine from a previous illness.

In some cases, over-the-counter medicines, also known as OTC medicines, may be suitable for mild symptoms with a relatively clear cause. However, these medicines still have limits regarding dosage, duration of use, side effects, warnings, and contraindications, just like other medicines.

What should be avoided is using leftover medicine, someone else’s medicine, or medicine recommended by another person without knowing whether it is truly suitable for your symptoms and health condition.

Why Should You Be Careful When Taking Medicine on Your Own?

Medicines have both benefits and risks. Even commonly used medicines can cause problems if used incorrectly. Possible risks include:

Using medicine that does not match the real cause of the symptoms
Taking too much or too little medicine
Using medicine for longer than recommended
Taking multiple medicines that contain the same active ingredient
Experiencing drug interactions
Developing side effects or allergic reactions
Using medicine that may not be suitable for an existing medical condition
Using medicine that may not be appropriate for children, older adults, pregnant women, or breastfeeding mothers

The World Health Organization emphasizes the importance of patient involvement in medication safety. Patients are encouraged to ask questions at key points, such as when starting a medicine, taking medicine, adding another medicine, reviewing medicines, and stopping medicine.

What Should You Check Before Taking Medicine on Your Own?

Know What Medicine You Are Taking

Always check the name of the medicine and its active ingredient on the label. Do not rely only on the brand name, color, or appearance of the tablet, because different brands may contain the same active ingredient. Knowing the active ingredient helps reduce the risk of taking the same medicine more than once, especially with combination products such as some cold medicines that may already contain pain relievers or fever reducers.

Use Medicine That Matches Your Symptoms

Do not choose a medicine simply because you had similar symptoms before and that medicine seemed to work. The same symptom can have many different causes. For example, a sore throat may be caused by a viral infection, bacterial infection, allergy, or irritation. The choice of medicine should depend on the likely cause and suitability. Leftover medicine from a previous treatment should not be used automatically.

Read the Label and Patient Information Before Use

Important information to check includes: recommended dose, how often the medicine should be taken, whether it should be taken before or after meals, how long the medicine can be used, contraindications and warnings, possible side effects, storage instructions, and expiry date. If you do not understand the label or instructions, ask a pharmacist before taking the medicine.

Do Not Increase the Dose on Your Own

Thinking that “taking one more tablet will make me recover faster” can increase the risk of side effects or overdose. Medicine should be taken according to the recommended dose and schedule. If symptoms do not improve despite correct use, consult a doctor or pharmacist instead of increasing the dose by yourself.

Do Not Use Someone Else’s Medicine

Even if the symptoms seem similar, a medicine that is suitable for one person may not be suitable for another. Each person may differ in age, body weight, underlying diseases, allergy history, and medicines currently being used. You should not share medicine with others or take medicine prescribed or recommended for another person.

Be Careful With Medicines That Contain the Same Active Ingredient

This problem is common with combination medicines, such as cold medicines, cough medicines, pain relievers, and fever reducers. If several products are taken together without checking their ingredients, you may accidentally receive the same active ingredient more than once. Before taking multiple medicines together, always read the ingredient list or ask a pharmacist.

Can Medicines, Supplements, and Herbal Products Interact With Each Other?

Yes. Some medicines can interact with other medicines, certain foods, alcohol, vitamins, supplements, or herbal products. These interactions may increase or reduce the effect of the medicine or increase the risk of side effects.

When buying additional medicine, you should inform your doctor or pharmacist about all products you are currently using, including: prescription medicines, over-the-counter medicines, vitamins, supplements, herbal products, or other health products. Keeping an updated list of the medicines and products you use and showing it to your doctor or pharmacist can help reduce the risk of drug interactions.

Who Should Be Extra Careful Before Buying Medicine on Their Own?

Some groups have a higher risk of side effects or medication-related problems than others.

Children: The correct dose for children may depend on age, body weight, and the type of medicine. Adult medicines should not be given to children by simply reducing the dose without professional advice.
Older Adults: Older adults often take several medicines at the same time. Liver and kidney function may also change with age, increasing the risk of drug interactions and side effects.
Pregnant or Breastfeeding Women: Some medicines can affect the unborn baby or pass into breast milk. Pregnant or breastfeeding women should consult a doctor or pharmacist before using any medicine, including herbal products, vitamins, and supplements.
People With Underlying Diseases: People with kidney disease, liver disease, heart disease, high blood pressure, diabetes, gastrointestinal disease, or other chronic conditions should inform the pharmacist before buying medicine. Some medicines may not be suitable for certain medical conditions.
People With a History of Drug Allergy: You should keep a record of the medicines you are allergic to and the symptoms you experienced. Always inform healthcare professionals about your allergy history before receiving any new medicine.

What Symptoms Mean You Should Stop the Medicine and Seek Urgent Medical Care?

If you develop symptoms that may indicate a serious allergic reaction or a medical emergency, do not wait and observe at home. Seek medical care immediately, especially if you experience:

Difficulty breathing, shortness of breath, chest tightness, or wheezing
Swelling of the lips, tongue, face, or throat
Dizziness, fainting, or loss of consciousness
Severe rash with blisters or peeling skin
Rash after taking medicine together with sores in the mouth, eyes, or genital area
Seizures or abnormal neurological symptoms
Severe unusual symptoms after starting a new medicine

If you suspect an overdose, do not wait until symptoms appear. Contact a healthcare facility or seek advice from a healthcare professional immediately.

When Should You See a Doctor Instead of Buying Medicine Yourself?

Self-medication is only appropriate for some mild symptoms. You should see a doctor if:

Symptoms are severe from the beginning
Symptoms do not improve within a reasonable period or become worse
Symptoms keep coming back
You have a persistent high fever or other concerning symptoms
You have chest pain, difficulty breathing, or fainting
You have abnormal bleeding
Pain is severe or progressively worsening
You are unsure what is causing the symptoms
You have multiple underlying diseases or take several medicines
The patient is a young child, older adult, pregnant woman, or breastfeeding woman and you are unsure whether the medicine is safe

Seeing a doctor does not always mean the illness is severe. If you are unsure about the cause or your symptoms do not improve after using medicine, proper assessment can help prevent an important condition from being missed.

How to Use Medicine Safely in Daily Life

Building safe medicine habits can reduce medication errors. You can start with simple practices such as:

Read the medicine name and label every time before taking it
Use medicine according to the recommended dose and schedule
Do not increase, reduce, or stop prescription medicine on your own
Do not share medicine with others
Keep medicine in its original packaging to avoid confusion
Check the expiry date before use
Keep medicines out of reach of children
Keep a list of medicines you take regularly, including vitamins and supplements
Inform healthcare professionals about any drug allergy history
Ask a pharmacist if you do not understand how to take a medicine

The World Health Organization promotes the concept of “5 Moments for Medication Safety,” which encourages patients to ask questions when starting, taking, adding, reviewing, and stopping medicines.

How Can a Pharmacist Help Before You Buy Medicine?

A pharmacist can help assess your symptoms and provide advice on safe medicine use, including:

Which medicine may be suitable for your symptoms
What dose to use and how long to use it
Whether there are any contraindications or precautions
Whether it can be taken with your regular medicines
What side effects to watch for
What symptoms mean you should see a doctor

To help the pharmacist assess your situation properly, provide accurate information about your symptoms, underlying diseases, allergy history, pregnancy or breastfeeding status, and all medicines, supplements, and herbal products you are currently using.

Summary

Buying or taking medicine on your own is not always dangerous if the symptoms are mild, the medicine is appropriate, and it is used correctly. However, every medicine has both benefits and risks. Medicine should not be used based only on past experience or advice from another person.

Before taking any medicine, you should know what it is, what it is used for, how to take it, and what precautions to follow. Do not increase the dose, use someone else’s medicine, or stop prescribed medicine on your own. If you are unsure, ask a pharmacist. If symptoms are severe, do not improve, or unusual symptoms occur after taking medicine, see a doctor for proper evaluation.

Prepared by: Pharm. Wiman Akkhaphanit

References

World Health Organization. 5 Moments for Medication Safety
U.S. Food and Drug Administration. Use Medicines Wisely
MedlinePlus, U.S. National Library of Medicine. Using Over-the-Counter Medicines Safely