Medicines information

Some medicines are available from pharmacists or supermarkets. Others require a prescription from your GP or another healthcare professional. The availability of medicines depends on the level of supervision that experts believe is necessary before you use a particular medicine.

Under laws that govern the supply of medicines, you can obtain medicine under three categories:

• prescription-only medicines (POMs)
• pharmacy (P) medicines
• general sales list (GSL) medicines

These are explained in more detail below.

Prescription-only medicines (POMs)

Prescription-only medicines (POMs) are only available with a prescription that is issued by a GP or another suitably qualified healthcare professional (see box, left). You need to see the healthcare professional before they give you a prescription.

You then take the prescription to a pharmacy or a dispensing GP surgery for your prescription to be dispensed. Examples of POMs are inhalers to treat asthma or medicines to lower high blood pressure (hypertension).

Pharmacy (P) medicines

Pharmacy (P) medicines are available from a pharmacy without a prescription but under the supervision of a pharmacist. You will need to ask staff at the pharmacy for this type of medicine because it is kept 'behind the counter' and is not available on the pharmacy shelves.

The pharmacist or another member of staff will check that the medicine is appropriate for you and for your health problem. They will ask you some questions to ensure that there is no reason why you should not use the medicine. An example of a medicine that you can buy from a pharmacy without a prescription is chloramphenicol eye drops to treat conjunctivitis (an eye infection).

General sales list (GSL) medicines

General sales list (GSL) medicines can be bought from pharmacies, supermarkets and other retail outlets without the supervision of a pharmacist. These are sometimes referred to as 'over-the-counter' (OTC) medicines.

OTC medicines include those that treat minor, self-limiting complaints, which people may feel are not serious enough to see their GP or pharmacist about. For example, paracetamol for the common cold or a headache, or antiseptic gel to treat minor cuts or grazes.

Can medicines change their status?

New medicines tend to be licensed in the POM category so that healthcare professionals can supervise their use during the first few years that they are available. If a medicine proves safe in large numbers of patients over several years, the regulatory agency may consider changing its status from POM to P.

European Union (EU) regulations encourage switching medicines from POM to P as long as there is no danger to health if the medicine is used without a prescriber's supervision and the medicine is unlikely to be used incorrectly.

If there have been no problems with a P medicine after several years of use, a switch to GSL status may be considered so that it can be sold directly from retail outlets.

Over the past 20 years in the UK, a wide range of medicines have been switched from POM to P and P to GSL. They include:

• ibuprofen for pain relief
• nicotine replacement therapy (NRT) for stopping smoking
• emergency contraceptive pills 
• clotrimazole and fluconazole for vaginal thrush

The government encourages increasing the availability of medicines where it is safe to do so.

Are P and GSL medicines as effective and safe as POM medicines?

If a medicine switches from POM to P or from P to GSL, the active ingredient remains exactly the same. This means that the medicine is just as effective as when it had to be prescribed by a qualified prescriber.

It also means that there is the same risk of side effects if you take too high a dose or if you do not follow the instructions on the label. Therefore, it is important that you follow the instructions carefully. Your pharmacist will be able to advise you about any possible side effects.