Appropriate polypharmacy for patients occurs when:

1. All drugs are prescribed for the purpose of achieving specific therapeutic objectives that have been agreed with the patient 
2. Therapeutic objectives are actually being achieved or there is a reasonable chance they will be achieved in the future
3. Drug therapy has been optimised to minimise the risk of adverse drug reactions (ADRs) 
4. The patient is motivated and able to take all medicines as intended.

Inappropriate polypharmacy occurs when one or more drugs are prescribed that are not or no longer needed, either because:

1. There is no evidence-based indication, the indication has expired or the dose is unnecessarily high
2. One or more medicines fail to achieve the therapeutic objectives they are intended to achieve
3. One or the combination of several drugs cause unacceptable adverse drug reactions (ADRs) or put the patient at an unacceptably high risk of such ADRs
4. The patient is not willing or able to take one or more medicines as intended.