目的：希望能對一些與鋰鹽吸收排泄有關的特質，找出一數學模式，作為臺灣人鋰鹽處方時的參考。方法：以過去五年內曾住某醫學中心精神科之雙極型情感性精神病病人為對象，選樣之準則是：該次住院以躁期為主，沒有重大身體疾病且腎臟功能正常、沒有飲食限制、沒有使用利尿劑、使用一般劑型之鋰鹽製劑、同一鋰鹽劑量至少使用一週以上、抽血之濃度資料明確及抽血前後三天內有測量體重者。結果：共有男性68人，女性67人，平均年齡29.9 ± 11.1歲、鋰濃度0.75 ± 0.24 mEq/L、鋰鹽劑量1160.1 ± 212.7毫克、體重 57.8 ± 10.7 公斤；逐步迴歸分析得到每天之鋰鹽劑量(毫克)=7.4 X 體重(公斤) -4.1 X 年齡(歲) + 139.6 X 血中濃度(mEq/L) + 765.0(常數)，其相關係數為0.4156；血中濃度在1.0 mEq/L時，每天鋰鹽劑量(毫克)=7.4 X 體重(公斤) -4.1 X 年齡(歲) + 904.6(常數)。另取符合前述條件者共44位病賽，其中男性21人，女性23人，平均年齡35.2 ± 12.7歲代入方程，其相關係數為 0.3424 (p=0.02)，預測值與實際劑量差值小於每天 150 毫克者有22人，佔百分之五十，差值介於每天150到300毫克者有13人，佔百分之三十，差值介於每天300到600毫克者9人，佔百分之二十。結論：影響上述公式之變數，若要參考時宜注意本研究樣本及其條件，建議仍應以常規定期檢測為主。

　　　　　Objective: To find a mathematical method for predicting lithium dose requirement. Method: In this study admission charts during past five years were reviewed. The inclusion criteria were a bipolar disorder in manic or hypomanic states, no major physicla problems, no food restrictions, no use of diuretics, and normal renal function. The data were collected when using the same doses of standard form lithium (carbonate) for at least one week and the time between measuring the body weight and lithium serum level is no longer than 3 days. Results: The study group was comprised of 135 patients (68 males, 67 females) with a mean age of 29.9 ± 11.1 years. The mean body weight, serum concertration and daily lithium dose were 57.8 ± 10.7kg, 0.75 ± 0.24 mEq/L and 1160.1 ± 212.7 mg respectively. Multiple regression analysis was done using the daily dose of lithium as the dependent variable. Independent variables include sex, age, body weight, lithium concentration and the additional prescription of neuroleptics, anticholinergics and tricyclic antidepressants. The results shows that daily lithium dose (mg) equals 7.4 x body weight (kg) -4.1 x age + 139.6 x lithium concentration (mEq/L) + 765.0 (constant) with a multiple R of 0.4156. When the expected lithium concentration is set at 1.0 mEg/L, the equation is simplified as daily lithium dose (mg) equals 7.4 x body weight (kg) -4.1 x age + 904.6 (constant). Testing this equation with another group of 44 cases (21 males, 23 females) under the same critera showed a statistically significant correlation between daily dose and serum concentration (r=0.34, P=0.02). The differences between predicting and actual oral doses ranging from less than 150 mg (22 cases, 50%), to between 150 mg (22 cases, 50%), to between 150 mg and 300 mg (13 cases, 30%) and 300 mg to 600 mg (9 cases, 20%). Conclusions: This is the first study of mathematical method for predicting lithium dose requirements in Taiwan. The applications of the equation are limited to this study group only. Larger groups study including different chronic users are recommended. The different predicting equations and methods are discussed in detail.