1 The Assessment of Therapeutic Compliance Based upon the Analysis of Drug Concentrations in Hair
John Williams, Ph.D.
CONTENTS
1.1 Major Issues of Therapeutic Noncompliance
1.2 Established Methods of Monitoring Therapeutic Compliance
1.2.1 Indirect Methods of Assessment
1.2.2 Direct Methods of Assessment
1.3 History of the Use of Hair in the Detection of Drugs
1.4 Physiology of Hair
1.5 Mechanism of Drug Incorporation into Hair
1.6 Studies on the Relationship between Drug Intake and Hair Concentration
1.7 A Prospective Study to Assess the Relationship between the Prescribed Dose of Carbamazepine and the Concentration of the Drug in Respective Samples of Hair and Plasma
1.8 Segmental Analysis of Hair and Its Temporal Relationship to Drug Taking
1.9 Overall Assessment of the Technique
References
1.1 MAJOR ISSUES OF THERAPEUTIC NONCOMPLIANCE
Compliance has been defined as âthe extent to which a patientâs behavior (in terms of medications, following diets, or executing life-style changes) coincides with the medical or health advice given.â In terms of therapeutic compliance, it relates to the taking of the prescribed medication as instructed by the clinician. Failure to adhere to these instructions, whether deliberately or unintentionally, is referred to as noncompliance.
This problem is not just a feature of recent times. The Greek physician Hippocrates wrote, âKeep watch also on the fault of patients which often make them lie about the taking of things prescribed,â as early as the 5th century B.C.
The reasons for noncompliance are diverse and are influenced by a variety of mitigating factors. In many cases, it is attributed to unintentional factors such as forgetfulness, particularly in the elderly where the problem can be further exacerbated by the complexity of the regimen. The greater the frequency that medication has to be taken, the greater the degree of noncompliance.1 Where patients are being treated for more than one clinical condition, noncompliance is invariably exacerbated.
In many cases, patients contradict the clinical diagnosis and become convinced that the medication is unnecessary. In a 1982 study, the American Association of Retired Persons,2 reported that 21 percent of patients over 45 years of age chose not to follow the recommendations of the physician from the outset and in effect became the primary decision makers.
Other reasons for noncompliance are that the patient perceives that the condition has improved. Very often there is concern about side effects either from personal experience or emanating from information published in newspapers or highlighted on television. About 10 percent can be attributed to the cost of the medication.
There is however little evidence to suggest that noncompliance is related to income, social class, occupation, or educational background.3
Whatever the reason for noncompliance, it presents a major problem in many areas of therapeutic medicine, and although technology and the pharmaceutical industries have gone to great lengths to devise methods of improving compliance, noncompliance remains as ...