Department Duin & Bollenstreek, Psychiatric Centre Rivierduinen, The Netherlands.
Int Clin Psychopharmacol. 2012 Mar;27(2):121-4. doi: 10.1097/YIC.0b013e32834e8afd.
St John's wort (Hypericum perforatum) is notorious for its ability to induce the enzymes of the P450 system. Especially, it induces CYP1A2 and CYP3A4, enzymes that are closely involved in the metabolism of clozapine. We present a patient with schizophrenia, who was stable on a fixed dose with stable plasma level of clozapine, and who deteriorated after she started self-medicating with St John's wort. The reduced plasma clozapine level and the psychiatric condition normalized after the withdrawal of St John's wort. It is possible that, beside the induction of P450-enzymes, the induction of P-glycoprotein by St John's wort aggravated psychiatric deterioration of the patient. Physicians should be alert to patients self-medicating with over-the-counter medicines, especially when these medicines can lower clozapine concentrations below the therapeutic range.
贯叶连翘（贯叶金丝桃）以其诱导 P450 系统酶的能力而臭名昭著。特别是，它诱导 CYP1A2 和 CYP3A4，这两种酶与氯氮平的代谢密切相关。我们介绍了一位患有精神分裂症的患者，她在服用固定剂量且氯氮平血药浓度稳定的情况下病情稳定，但在开始自行服用贯叶连翘后病情恶化。贯叶连翘停用后，氯氮平的血药浓度降低，精神状态恢复正常。可能除了诱导 P450 酶外，贯叶连翘还诱导 P-糖蛋白，从而加重了患者的精神恶化。医生应该警惕患者自行服用非处方药，尤其是当这些药物会导致氯氮平浓度降至治疗范围以下时。
