Orengedoku-to augmentation in cases showing partial response to yokukan-san treatment: a case report and literature review of the evidence for use of these Kampo herbal formulae

Background: Yokukan-san, a Japanese traditional herbal (Kampo) prescription, has recently gathered increasing attention due to accumulating reports showing its remarkable efficacy in treating a wide variety of diseases refractory to conventional medicine as well as the behavioral and psychological symptoms of dementia. As yokukan-san has become broadly integrated with conventional medicine, augmentation therapy with other Kampo prescriptions has become necessary when the yokukan-san has been only partially efficacious. In this paper, we report three cases in which the addition of orengedoku-to, another Kampo formula, to yokukan-san was remarkably effective. Cases: Case 1 was an 85-year-old man with Alzheimer-type dementia who had become aggressive during the past 2 years. Three milligrams of aripiprazole completely suppressed his problematic behaviors but had to be stopped because of extrapyramidal symptoms. In the second case, a 44-year-old man with methamphetamine-induced psychosis had suffered from serious tardive dystonia for 2 years. No conventional approach had improved his tardive dystonia. The third case was a 29-year-old engineer who often failed to resist aggressive impulses and was diagnosed with intermittent explosive disorder. He was prescribed 5 mg of olanzapine, which did not suppress his extraordinary anger and caused somnolence even though the dose was low. Interventions and outcomes: Yokukan-san was complementarily added to the patients' regular medication and exerted a definitive but partial effect in all cases. The addition of orengedoku-to to yokukan-san exerted the same efficacy as aripiprazole in controlling aggressiveness in Case 1, improved the tardive dystonia by 80% in Case 2, and was completely effective in controlling the patient's aggressive impulses in Case 3. Conclusion: Together with empirical evidence demonstrating the effectiveness of both yokukan-san and orengedoku-to in reducing irritability, impulsivity, and aggression, these three cases suggest that orengedoku-to augmentation can be an effective option in cases that are partially responsive to yokukan-san treatment.