All About Drug Therapy Problem (DTP) In Pharmaceutical Care (PC)

A drug therapy problem (DTP) is any undesirable event experienced by a patient which involves, or is suspected to involve, drug therapy, and that interferes with the desired goals of therapy. Drug therapy problems are not medical problems. They are problems caused by the use or misuse of drugs.

Drug therapy problem

Drug-related problems include medication errors (involving an error in the process of prescribing, dispensing, or administering a drug, whether there are adverse consequences or not) and adverse drug reactions (any response to a drug which is noxious and unintended, and which occurs at doses normally used in humans for prophylaxis, diagnosis or therapy of disease, or for the modification of physiological function). Furthermore, adverse drug events can be defined as an injury--whether or not causally-related to the use of a drug.

Types Of Drug Therapy Problem

A drug therapy problem may be potential (likely to occur) or actual (patient is already experiencing it).

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Classification Of Drug Therapy Problem

All patient problems involving medications can be categorized into seven (eight in some clarification) types. These include all side effects, toxic reactions, treatment failures, or the need for additive, synergistic, or preventive medications, as well as noncompliance.

The first two categories of drug therapy problems are associated with the indication. The third and fourth categories of drug therapy problems are associated with effectiveness. The fifth and sixth (third one here in some classification) categories of drug therapy problems are associated with safety. The seventh category deals with patient compliance.

Indication

1. Additional drug therapy needed

a. untreated indication

b. preventive/prophylactic

c. synergistic/potentiating

2. Unnecessary drug therapy being used (e.g. duplicate therapy): The patient is taking a drug therapy that is unnecessary given his or her present condition

a. no medical indication

b. duplicate therapy

c. Non-drug therapy indicated

d. treating avoidable adverse drug reaction

Effectiveness

3. Ineffective drug therapy (wrong drug including dosage form): The patient has a medical condition for which the wrong drug is being taken

a. requires different drug product

b. more effective drug available

c. condition refractory to drug

d. dosage form inappropriate

e. not effective for condition

4. Dosage too low (dose, frequency, duration): The patient has a medical condition for which too little of the correct drug is being taken

a. wrong dose

b. frequency inappropriate

c. duration inappropriate

d. drug interaction

Safety

5. Adverse drug reaction: The patient has a medical condition resulting from an adverse drug reaction

a. undesirable effect

b. unsafe drug for patient

c. dose changed too quickly

d. allergic reaction

e. contraindications present

6. Drug interaction (pharmaceutic, pharmacodynamic, pharmacokinetic): The patient has a medical condition resulting from clinically significant drug interactions.

7. Dosage too high (dose, frequency, duration): The patient has a medical condition for which too much of the correct drug is being taken

a. wrong dose

b. frequency inappropriate

c. incorrect administration

d. drug interaction

Convenience

8. Adherence to therapy: The patient has a medical condition resulting from not taking the drug appropriately (explore missed doses and reasons).

a. directions not understood

b. patient prefers not to take

c. patient forgets to take

d. drug product too expensive

e. cannot swallow/administer

f. drug product not available

Causes Of Drug Therapy Problem

The causes of drug-related problems are multifactorial. In this post, let us look at each drug therapy problem and the cause.

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Unnecessary drug therapy

1. No medical indication

2. Addiction/recreational drug use

3. Non-drug therapy more appropriate 

4. Duplicate therapy

5. Treating avoidable adverse reaction

Wrong drug

1. Dosage form inappropriate

2. Contraindication present

3. Condition refractory to drug 

4. Drug not indicated for condition

5. More effective drug available

Dosage too high

1. Wrong dose

2. Frequency inappropriate

3. Duration inappropriate

4. Drug interaction

Adverse drug reaction

1. Unsafe drug for patient

2. Allergic reaction

3. Incorrect administration

4. Drug interaction

5. Dose increased/decreased too quickly

6. Undesirable effect

Inappropriate adherence

1. Drug product not available

2. Cannot afford drug product

3. Cannot swallow/ administer drug 

4. Does not understand instructions

5. Patient prefers not to take drug

Needs additional drug therapy

1. Untreated condition

2. Synergistic therapy

3. Prophylactic therapy

Identifying Drug Therapy Problems

Identifying a drug therapy problem is a clinical judgment that requires the practitioner to identify an association between the patient's medical condition and the patient's pharmacotherapy. Medication management services add value to the care of individual patients by identifying, resolving, and preventing drug therapy problems. Identifying, resolving, and preventing drug therapy problems are the unique contributions of the pharmaceutical care practitioner.

All practitioners who deliver pharmaceutical care must be capable of identifying, preventing, and resolving all of the seven types of drug therapy problems for a given patient. A correctly stated drug therapy problem includes

a) a description of the patient's condition or problem

b) the drug therapy involved, and

c) the specific association between the drug therapy and the patient's condition.

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How the practitioner describes the drug therapy problem influences the selection of interventions to resolve the problem. When multiple drug therapy problems exist, priority is given the problem that is most important to the patient and/or is critical to the health of the patient. Patients who have no drug therapy problems still require a care plan and follow-up evaluation to ensure that the goals of therapy continue to be met and no new drug therapy problems develop.

Skills Needed To Identify Drug Therapy Problem

Pharmacists are better equipped to identify actual and potential drug therapy problems. Equipe with patients' data and critical thinking skills, resolving drug therapy problems is a must. Crosscheck medical condition/complain with all indicated drugs and see if all condition is treated with or without drug and that every condition is under treatment.

The analysis begins with each indication. If all drugs are necessary, then what about the dose and frequency. What about the safety, efficacy, cost effectiveness, availability, etc.

Then move over to possible side effects and or actual side effects and interaction with other drugs. Look at the compliance level of the patient to see and find out the reason if there is failure. Could the frequency be too high, drugs too expensive, foul odour, colour or dosage form of drug is not comfortable with the patient?. Lastly, check to see if there is any complaint or medical condition not yet treated.