Antidepressant blood levels in Southeast Asians. Clinical and cultural implications

After long-term treatment with tricyclic antidepressants (TCA), the TCA blood levels of 41 depressed Southeast Asian patients were determined by high-pressure liquid chromatography. No detectable medicine level was found in 25 (61%) of the patients and a therapeutic level by American standards was found in only six (15%), indicating a high incidence of noncompliance. A Cambodian subgroup, however, was significantly more compliant than either the Vietnamese or Mein patients. After patient education and a discussion of problems and benefits of medicine, compliance improved with Vietnamese and Cambodians but not with the Mien. Cultural and educational factors influence compliance with medicine and responsiveness to education. Because the Cambodians also suffered from posttraumatic stress disorder, it is probable that the presence of this illness increased compliance. Preliminary data among these patients indicate that Asians probably need the same dose of imipramine as Americans to achieve a "therapeutic" level. Reports that Asians need lower doses of TCA medicine are limited by the high noncompliance rates with Asians. These high rates probably reflect cultural beliefs about illness and medication usage. It is valuable to perform TCA blood levels on Asian patients for whom antidepressants have been prescribed to monitor compliance and to lead into a discussion of benefits and side effects of the medicine. Evidence of noncompliance can lead to a productive doctor-patient discussion about beliefs and effects of the medication.