Table 2 Classification and definition of drug therapy problems

Indication

Does the patient have an indication for each of his/her drug therapies, and is each of the patient's indications being treated with drug therapy?

Additional drug therapy required

The patient has a medical condition or is experiencing symptoms that requires the initiation of new or additional drug therapy or is at a high-risk to develop a new medical condition for which additional drug therapy is indicated.

Unnecessary drug therapy

The patient is taking drug therapy that is unnecessary given his or her present condition or the patient is at risk to develop a new medical condition that is a result of taking an unnecessary drug for which there is no valid medical indication.

Effectiveness

Are the drug therapies effective for his/her medical condition? Are the intended outcomes of drug therapy reached?

Ineffective drug therapy

The drug product is not being effective at producing the desired response. The patient is not experiencing the intended positive outcome from a certain drug regimen or the intended outcome is not reached. Or an alternative drug therapy has a higher probability of producing the desired outcome, or an alternative drug therapy is equally effective but less expensive.

Dosage too low

The patient has a medical condition for which too little of the correct drug is being taken to produce the desired beneficial outcome or the patient is at risk to develop a new medical condition because too little of the correct drug is being taken to expect a beneficial outcome. The patient's drug concentration in the body can be below the desired therapeutic range or the timing of prophylaxis can be inadequate for the patient or dose and interval can be inadequate for the patient or drug, dose, route or formulation conversions were inadequate for the patient.

Safety

Are the drug therapies as safe as possible? Is everything done to keep them as safe as possible?

Adverse drug event

The patient has a medical condition or is experiencing symptoms or is at risk of developing a medical condition which is undesired effect and is related to the drug therapy. This can be an idiosyncratic reaction to the drug, an allergic reaction to the drug or a pharmacologically expected reaction to the drug, possible due to a medication error.

Dosage too high

The patient has a medical condition for which too much of the correct drug is being taken or the patient is at risk to develop a new medical condition because too much of the correct drug is being taken. The patient's drug concentration in the body can be above the desired therapeutic range or the drug dose escalating can be too rapidly or there can be drug accumulation from chronic administration or dose and interval can be inadequate for the patient or drug, dose, route or formulation conversions were inadequate for the patient.

Drug use

Is the patient able and willing to comply with the drug therapies as prescribed? Are the drug therapies as convenient as possible to the patient?

Drug use problem

Drug use problem is defined as the patient's inability or unwillingness to take a drug regimen that the GP, pharmacist or other health care provider has clinically judged to be appropriately indicated, adequately efficacious and able to produce the intended outcomes without any undesired effects.