目的︰鋰鹽已是廣被接受的情緒穩定劑，對於急性或慢性之情感性精神病有治療與維持作用。在國內外許多文獻報告過鋰鹽中毒，尤其是有關電解質之不平衡，造成之鋰鹽中毒或是腎臟功能異常而發生之鋰鹽中毒，但有關藥物互相作用而發生之鋰鹽中毒在國內並不多見，尤其是鋰鹽與抗生素互相作用而造成鋰鹽中毒，更是少見。病例報告︰一位躁鬱症病患，於鋰鹽同時併用四環黴素後，出現鋰鹽中毒之情況，文中並討論造成此種中毒之可能機轉。結論︰提醒臨床精神科醫師，須對鋰鹽與抗生素同時使用之病患，密切注意血中之鋰鹽濃度。

　　　　　Objective: Lithium is a well-known and widely used mood stabilizer. It has been used in acute treatment and long-term prophylactic treatment of affective disorders. Lithium intoxication occurs frequently in electrolyte imbalance and renal function impairment. Lithium intoxication cases have been extensively reported all over the world. However, drug interaction with lithium has rarely been reported in Taiwan. Case Report: In this case, lithium intoxication occurred in a manic depressive psychosis patient who was taking tetracycline and lithium. Conclusion: We would like to remind every psychiatrist to frequently monitor serum lithium levels of the patients who are taking lithium and antibiotics at the same time.