Medicines: understanding your medicines

When your doctor gives you a prescription, they have made a careful decision about choosing the right medicine for you. Taking a prescribed medicine correctly also involves taking the medicine in the right dose, by the right route and at the right time. You have been part of the decision-making process by answering questions so your doctor has a complete medical history.

As part of this process, you have told your doctor about any previous allergic reactions to medicines that you have suffered. You have told your doctor about any types of medicines that you may be currently taking (remembering that vitamins, minerals, herbal and food supplements and over-the-counter medicines all need to be considered).

You need to tell your doctor about any chronic health problems you may have, and whether you are pregnant or breast feeding.

Once you leave your doctor there are still a number of responsibilities you must assume.

Understanding your responsibilities

You must know how to administer the medicine you will be taking properly, and how to comply with the dosing schedule. You should be aware of any possible side effects identified for that medicine, so you know what to expect. Always ask your doctor or pharmacist about side effects.

Importantly, you need to be aware of the signs or symptoms that may indicate the need to contact your doctor about a potential problem with the medicine. Unfortunately, often people will leave their doctor's office without understanding the treatment they are about to start and this often means that they are unable to comply with their doctor's advice.

Things you should not do

Do not stop taking the medicine before it has had a chance to work properly — even if you don't think it is working, or you start feeling better. If you experience unpleasant side effects contact your doctor or pharmacist.

Do not take the medicine in incorrect dosages or at the wrong time, and don't take the medicine in higher doses or at more frequent intervals than it has been prescribed.


Sometimes medicines can mix with other medicines you are already taking to cause negative effects. These can affect how well the medicine works or change the side effects of the medicine. Certain foods and alcohol can also affect the way medicines work. These effects are known as drug interactions. Interactions occur most commonly when starting or stopping a medicine and with an increased dose of a medicine. Always ask your doctor or pharmacist about any interactions you should be aware of when you start a new medicine.

Always check your medicine's label, to see if there are special instructions regarding food and alcohol intake with your medicine and follow these instructions carefully. If you are unsure about drinking alcohol while taking a medicine, ask your doctor or pharmacist directly.

Consumer Medicines Information

It is also important to read the Consumer Medicines Information (CMI) leaflet that comes with your medicine, as well as the instructions provided by the pharmacist regarding your medicine. You can search myDr's CMI directory to find your medicine.

Precautions to take before taking any medicines

There are several precautions to bear in mind before you take any medication.

  • Become familiar with the exact effects of your medicine. Discuss potential effects and side effects with your doctor so you know what to expect.
  • Always follow the instructions that come with your medicine carefully. If in doubt, ask your doctor or pharmacist.
  • Discuss with your doctor any alternatives to the medicine if you are not sure about the one being prescribed. Remember that all drugs affect the body and one may suit you better than another.
  • Be sure to keep your doctor informed of all types of treatments that you are taking, including over-the-counter products, vitamins, minerals, and herbal and food supplements, as they may interact with the prescribed drug.
  • Always discuss over-the-counter products with your pharmacist to make sure that the product you purchase will not interact with your prescribed medicines.
  • Discuss with your doctor or pharmacist what precautions (if any) should be taken when using the medicine. For example, alcohol often has an adverse reaction with other drugs, and other medicines may make you drowsy.
  • Don't share your medicines with anyone else, even if they have the same symptoms. Similarly, don't use anyone else's medicines. Different drugs have different effects on different people and you may experience a bad reaction to someone else's medicine.
  • Do not keep old medicines around the house, especially if they have passed their use-by date. Out-of-date medicines can have dangerous effects.
  • Keep all medicines out of the reach of children and seek medical advice immediately if any medicine is taken accidentally. For poisoning emergencies, call the Poisons Information Centre on 13 11 26
  • Don't assume that it is safe to drive when taking medicines (even some over-the-counter preparations such as cold and 'flu tablets can be a problem). If the medicine causes you to feel drowsy, dizzy, shaky, nauseous, anxious, or if the medicine causes problems with vision, you should not drive a car.

If in doubt about any medicine ask your doctor or pharmacist.


1. National Prescribing Service (NPS). Understanding interactions. Oct 2012. (accessed Dec 2012).
2. National Prescribing Service (NPS). Side effects and interactions. Oct 2012. (accessed Dec 2012).
3. National Prescribing Service (NPS). Making wise choices about medicines. Oct 2012. (accessed Dec 2012).