Is it a side effect? How to tell, and what to do next

Starting a new medicine usually comes with relief: finally, something to help. Then, a few days in, you notice something new. A dry mouth, a mild headache, a bit of nausea, or feeling more tired than usual.

The worry sets in quickly. Is the medicine making me sick? Should I stop taking it?

Feeling uneasy is completely normal. Knowing how your body adjusts to a new medicine can help you decide calmly what to do next.

Your body adjusting, or a true side effect?

When you take a new medicine, your body has to absorb it, process it and get used to it.

• Your body adjusting. Many mild symptoms, like slight nausea or a passing headache, are your body getting used to the medicine. They often ease within the first week or two.
• A side effect that needs attention. This is a reaction that doesn’t settle, gets worse over time, or gets in the way of your daily life.

What to do right now

1. Get help immediately for warning signs. Swelling of the face, lips or tongue, difficulty breathing, a widespread rash or fainting can be signs of a serious reaction. Call 10177 or go to your nearest emergency unit.
2. Don’t stop on your own. For most medicines, stopping suddenly can do more harm than a mild side effect, especially for long-term conditions. Speak to your doctor or pharmacist first.
3. Keep a simple record. Write down what you feel, when it started, how long it lasts, and whether it happens before or after meals. This helps whoever you speak to work out what is going on.
4. Ask for a proper look at the whole picture. A pharmacist can go through everything you take, including vitamins and over-the-counter products, and help you understand what might be causing the symptom and what to raise with your doctor.