As practising clinicians, prescribing is one of our everyday routines. With ongoing developments in clinical pharmacological research, newer drugs are being available almost daily for clinicians to choose. The newer generations of drugs tend to be pharmacologically more complex and more potent. Meanwhile, the population is ageing and polypharmacy is on the rise. The risks of drug interactions and drug adverse reactions are also seen increasing, making prescribing a more and more challenging task.¹ The following is meant to stimulate some thoughts on the subject.

According to researchers,¹ there is much evidence to show undesirable prescribing behaviours in the UK. On the one hand effective treatments, like angiotensin converting enzyme inhibitors for heart failure² and statins for hyperlipidaemia,³ are found to be underprescribed. On the other hand,prescription errors are also common.⁴ Approximately 6.5% of admissions to UK hospitals are related to adverse drug reactions, with an associated mortality of 0.15 % - costing the UK 466m (approximately HK$7000m) annually.⁵

There are a multitude of reasons for undesirable prescribing behaviour and prescribing errors to happen.^4,6 Some are issues related to the training and continuing professional development of individual prescribing doctors. Others are related to the system itself.

Going back to basics, are prescribers getting enough teaching and training when they were medical students to prescribe when they start practice? In 1994, UK medical students received a median 61 hours of teaching relating to pharmacology, clinical pharmacology, and therapeutics.⁷ According to recent figures, the numbers of pharmacologists and clinical pharmacologists in the UK (and thus the amount of teaching) have since decreased.^8,9 Is the time spent enough for us to have an integrated scientific and clinical base to prepare us to perform adequately for proper prescribing? Once the medics leave medical schools, are there any mechanism to follow up their prescribing behaviours?

Regarding the system, different hospitals and clinics have different prescribing sheets. Should there not be a uniform format to reduce the chance of making mistakes? Would the advances in information and technology not be helpful to prescribers in general, computerized records and so on?

Polypharmacy could mean either many drugs or too many drugs.¹⁰ Although, the term polypharmacy is generally used in a negative sense, polypharmacy can be applied in some clinical conditions with favourable effects. Diabetes mellitus can often be treated with several drugs at the same time.¹¹ A combination therapy approach is used in the treatment of tuberculosis, Helicobacter pylori and AIDS.¹¹ Therefore, the problem of polypharmacy is not in number of drugs prescribed but lies in whether each drug has been prescribed appropriately or inappropriately, both individually and in the context of the whole prescription.¹¹ Inappropriate polypharmacy is associated with increased risk of having adverse drug reactions and interactions, which is to be avoided.

It is not easy to find a straightforward and perfect answer to this subject. Adequate training at the beginning, with continuing professional development and the help of computerized records and system adoptions, topped up with an audit mechanism may help to reduce the iatrogenic effects of prescriptions.