Scharman E J, Hutzler J M, Rosencrance J G, Tracy T S
West Virginia Poison Center, Charleston, USA.
Ther Drug Monit. 2000 Oct;22(5):566-73. doi: 10.1097/00007691-200010000-00011.
Syrup of ipecac (SI) has been used medicinally since the 1500s; however, little is known about the pharmacokinetics in humans of SI's active ingredients, emetine and cephaeline. The objective of this study was to evaluate the rate of absorption and the rate of elimination of emetine and cephaeline. Ten healthy, adult, human volunteers between 18 and 45 years of age who were of ideal body weight (body mass index 20-25) completed this study. After an overnight fast, 30 mL SI were ingested. Blood samples were collected 30, 45, 60, 90, 120, 150, and 180 minutes post-ingestion and urine was collected throughout the study period. Plasma and urine concentrations of emetine and cephaeline were measured by reverse-phase HPLC with fluorescence detection. In virtually all subjects, emetine and cephaeline were detected within 5-10 minutes of dosing with the time to maximum concentration being approximately 20 minutes. The mean areas under the concentration-time curve (AUC) for both emetine and cephaeline were similar; however, the ratio of mean cephaeline maximum concentration (Cmax) to emetine Cmax was approximately 1.5. Four of the ten subjects exhibited a type of concentration-time profile in which the levels of cephaeline were substantially higher than those of emetine and the levels of cephaeline were substantially higher than noted for the other six subjects. In these remaining six subjects, the levels of emetine and cephaeline were lower than 10 ng/mL at all time-points. An initial elimination phase was noted in some subjects but not in others. Individuals in whom an initial elimination phase was not observed also exhibited low levels of both alkaloids as compared with the other subjects suggestive of a slower distribution phase. Less than 0. 15% of the administered emetine and cephaeline was recovered in the urine at 3 hours. No relationship between vomiting episodes and peak concentrations of emetine or cephaeline was found. Administration of SI results in rapid appearance and disappearance of emetine and cephaeline in plasma becoming almost undetectable at 3 hours. Very little of either alkaloid is eliminated in the urine within this time period, suggesting extensive distribution. The length of time that an administered dose of SI can result in the detection of emetine and/or cephaeline in the urine has not been determined; future studies in humans are required.
吐根糖浆（SI）自16世纪起就被用于医学；然而，对于SI的活性成分吐根碱和吐根酚碱在人体中的药代动力学却知之甚少。本研究的目的是评估吐根碱和吐根酚碱的吸收速率和消除速率。10名年龄在18至45岁之间、体重理想（体重指数20 - 25）的健康成年志愿者完成了本研究。经过一夜禁食后，受试者摄入30 mL SI。在摄入后30、45、60、90、120、150和180分钟采集血样，并在整个研究期间收集尿液。采用反相高效液相色谱荧光检测法测定血浆和尿液中吐根碱和吐根酚碱的浓度。几乎在所有受试者中，给药后5 - 10分钟内检测到吐根碱和吐根酚碱，达到最大浓度的时间约为20分钟。吐根碱和吐根酚碱的平均浓度 - 时间曲线下面积（AUC）相似；然而，吐根酚碱的平均最大浓度（Cmax）与吐根碱Cmax的比值约为1.5。10名受试者中有4名呈现出一种浓度 - 时间曲线特征，即吐根酚碱的水平显著高于吐根碱，且吐根酚碱的水平显著高于其他6名受试者。在其余6名受试者中，吐根碱和吐根酚碱在所有时间点的水平均低于10 ng/mL。在一些受试者中观察到了初始消除相，但在另一些受试者中未观察到。未观察到初始消除相的个体与其他受试者相比，两种生物碱的水平也较低，这表明其分布相较慢。给药后3小时，尿液中回收的吐根碱和吐根酚碱不到给药量的0.15%。未发现呕吐发作与吐根碱或吐根酚碱的峰值浓度之间存在关联。服用SI后，血浆中吐根碱和吐根酚碱迅速出现和消失，3小时时几乎无法检测到。在此时间段内，两种生物碱在尿液中的消除量极少，表明分布广泛。服用一定剂量的SI后，吐根碱和/或吐根酚碱在尿液中能够被检测到的时间长度尚未确定；未来需要在人体中进行研究。
