When the Patient Won't Take the Medicine
In light of the importance of drug therapyin clinical disease, nonadherencehas become a major public healthproblem. Nonadherence is estimated at~40%, with some studies showing that itmay be as high as 75%.1-3 In terms ofcost, nonadherence rivals that of cancer,Alzheimer's disease, and diabetes.4 Itresults in reduced efficacy or diseasedeterioration, with detrimental effects onpatient health and quality of life, as wellas increased morbidity and mortality.
Nonadherence is a precursor to increaseddrug expenditures. The averagemonthly cost of drugs prescribed fornonadherent patients is almost 3 timeshigher than the cost of drugs for thosepatients who adhere to their drug regimen.3,5 Studies have shown that $11 billionis spent annually servicing poortherapeutic outcomes associated withnonadherence.2,5
Reasons for Nonadherence
All patients should be screened formedication adherence. Patients with thehighest risk for nonadherence are as follows6,7:
- The elderly
- Patients taking >3 medications
- Patients seeing multiple physicians
- Patients with multiple disease state
- Patients with poor recall of their drugregimen
- Patients who develop excessive sideeffects or drug interactions
One study revealed that 59% of theelderly on long-term therapy make >1errors when taking their medications,with 26% making a potentially seriouserror and 66% of these errors beingerrors of omission.8-10 Many elderlypatients who omit medications do sodeliberately. Many think that they do notneed the medication or that the dose istoo strong.
A large percentage of patients, especiallythe elderly, lack basic informationabout their medications. Many are notinformed about the drug name, purpose,dosage schedule, duration of therapy,side effects, and adverse consequences(eg, what happens if they stop taking themedication).
In a Seattle, Wash, study, only 44% ofpatients using prescription drugs couldrecall a pharmacist instructing them onthe drugs' use, whereas 80% recalledthat their physician had done so. Only52% reported that their physician hadinstructed them about possible sideeffects, and only 30% reported receivingthis information from their pharmacist.3,11
Nonadherence-induced disease deteriorationhas been observed in patientswith hypertension, diabetes, seizures,and HIV, as well as in patients who havehad an acute myocardial infarction (AMI).
A study by Newby and colleagues12showed that long-term adherence to secondary-prevention therapies for coronaryartery disease (CAD) remains poor. Nearly50% of the patients with CAD in the 7-year study admitted that they did notconsistently take -blockers, lipid-loweringtherapy, aspirin, or angiotensin-convertingenzyme inhibitors. The study alsorevealed that nonadherence was greateramong people with the highest risk ofpoor outcomes, who could benefit fromincreased medication adherence.
The results of 2 other studies showedthat nonadherence to medications iscommon among recent AMI patients andin patients with diabetes, resulting inhigher mortality. Nonadherence in theAMI study resulted in an almost fourfoldincrease in the death rate in the first yearafter hospital discharge.13 The diabetesstudy showed almost a twofold increasein mortality following nonadherence.14
A study by Chapman and associates15showed that, within 3 months of startingboth antihypertensive and lipid-loweringtherapies, less than half of the patientswere taking both medications as prescribed.
Nonadherence actually increases thepatient's risk of receiving additionalunnecessary medications. Nonadherenceand the disease deterioration itcauses can lead to the following6:
- Continuing existing drug therapy atan increased dose
- Adding a new medication to theregimen
- Stopping the initial medication that isperceived as ineffective and replacingit with another medication
Because polypharmacy can result innonadherence, a patient's drug regimenshould be assessed periodically, and thefollowing questions should be asked16:
- Is each drug necessary?
- Is the medication contraindicated inthe elderly?
- Does the patient have duplicatemedications in the regimen?
- Is the patient taking the lowesteffective dose?
- Is the medication intended to treat aside effect of another medication?
- Can the drug regimen be simplified?
- Does the regimen have potentialdrug interactions?
- Is the patient being adherent?
- Is the patient taking any OTC products,herbals, or other medications?
In order to increase medication adherence,cost needs to be considered.Researchers in Canada17 looked at 290chronically ill patients discharged fromthe hospital. The investigators discoveredthat drug cost was the primary reasongiven for nonadherence to their drugtreatment.
Physicians and pharmacists need toinquire about patients' ability to affordthe medications prescribed. The followingquestions may provide importantinformation18:
- Are there circumstances that makeit difficult for you to fill your prescriptions?
- If I changed your medication to a lessexpensive drug, would it be helpful?
- (For patients on managed care plans)Do you exceed your monthly orquarterly cap for medication coverage?
- (For patients with poorly controlleddiabetes) Are you testing your bloodsugar less often because you are tryingto conserve supplies?
Physicians and pharmacists must functionas teachers, motivators, and persuaders.Indeed, these health care professionalsare asking patients to takemedications for chronic disease fordecades. Communication is among themost important factors in order forpatients to adhere to their drug regimens.
Many elderly patients suffer from poorhearing, vision, and joint mobility. Patientsshould be asked to repeat informationthey are told to make sure that theyunderstand. Studies have demonstratedthat, if patients know why they are takinga medication, they will be more adherentand less likely to have another medicationprescribed.6,19,20 Patients with arthritisshould be asked whether they canopen containers with a childproof cap.
Dr. Dutcher is a clinical pharmacistfor B&B Clinical Consultants, PuntaGorda, Fla.
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