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Medicines – when can problems occur?

Key points about when problems can occur with medicines

Medicines are important to manage your health, but sometimes they can cause problems.
Problems with medicines are usually due to side effects, interactions and mistakes.
This page describes when problems are most likely to happen and tips to help you avoid them.

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Problems with medicines are usually because of side effects, interactions and mistakes.

Side effects from medicines can range from mild symptoms, such as drowsiness or feeling sick (nausea), to life-threatening conditions, although these are rare. Some side effects may go away once your body gets used to the medicine, but some side effects can last much longer and be troublesome.
Interactions can happen if more than one medicine is taken. This can change the way a medicine works, or cause side effects. Some medicines also interact with herbal supplements, vitamins, foods or drinks.
Mistakes – on rare occasions, health professionals make mistakes when they prescribe or give you a medicine. They may forget about the interactions or get the dose wrong. You can also make mistakes with your medicines if you get confused about when and how to take them.

It’s good to know what you can do about these. Read more about how to avoid problems when any of the following apply:

If you take more than a few medicines, it’s also recommended you get all your medicines reviewed. A medicine review involves meeting with a doctor, nurse or pharmacist to talk about all of your medicines.

This information is used to check that you're taking the most appropriate medicines and that you know how to take them safely. You will have the opportunity to ask questions about your medicines and talk about any concerns you have. Read more about medicine reviews.

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Side effects are more likely when starting new medicines. This can happen because your body isn’t used to the medicine yet. With time, most side effects go away. If you're already taking medicines, starting a new one may cause an interaction between them.

Tip: When you're prescribed a new medicine ask your healthcare provider about the most likely side effects and interactions, and if there's anything you can do. Read more about side effects of medicines.

Side effects can depend on the dose of the medicines you are taking. Generally, you're more likely to notice side effects with higher doses and when you're increasing your dose.

Changes to your normal doses or changes in the strength of your medicine can be confusing, leading to you taking the wrong dose.

Tip: If your medicine dose has changed, ask your healthcare provider what side effects to expect. Take your old medicines back to your pharmacy once you no longer need them. They can dispose of them safely. Read more about returning expired or unused medicines to your pharmacy.

Medicines, including herbal supplements, vitamins and minerals, that you can buy over the counter from a pharmacy or supermarket, can have side effects and cause interactions with your other medicines.

Tip: Before buying a medicine or supplement over-the-counter, talk to your pharmacist about your current medicines and medical conditions. They can check if the new medicine or supplement is safe to take with your other medicines. If it isn't, they may be able to suggest a safer one.

Image credit: Healthify He Puna Waiora

Changes to medicines are very common during a stay in hospital. New medicines may be started, or medicines you've been taking may be changed or stopped. This can increase the chance of problems when you go home. Some of these changes may only be short-term but other changes may be longer. You may:

be taking more medicines after you leave hospital
have to stop taking some of your medicines
have to take your usual medicines differently.

Tip: If you've just spent time in hospital, ask your healthcare provider to go through and explain each of your medicines with you, especially the ones that are changing.

You can ask to have a family or whānau member with you when your new medicines are explained before you leave the hospital. Read more about questions to ask about your medications.

You can also ask for a printed list of your current medicines to take home with you.

All the people involved in your healthcare need to know about all the medicines you're taking, including:

prescribed medicines
over-the-counter medicines from a pharmacy or supermarket, and
any herbal supplements or rongoā Māori.

This will help to make sure your healthcare providers have all the information they need when prescribing or recommending medicines for you.

Tip: Keep a list of your medicines and supplements (also called a 'yellow card' in Aotearoa New Zealand) and update it whenever there's a change. Take your list with you when you see your healthcare providers or go into hospital. Tell everyone involved in your healthcare about every medicine you're taking.

Problems can happen if you take a medicine that's not prescribed or recommended for you by a healthcare provider.

What's safe and effective for one person, even someone with the same medical condition as you, may not be right for you. Your health changes over time and medicines that were safe for you in the past may no longer be suitable.

Don’t assume a medicine will be okay to take. Always ask for professional advice from your healthcare provider.

Tip: Don’t share medicines with other people, even if they have the same health condition as you. Take your old medicines back to your pharmacy once you no longer need them. They can dispose of them safely. Read more about returning expired or unused medicines to your pharmacy.

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