The Pharmacology of Emetin

The maximum plasma radioactivity levels of tritium (3H)-labeled cephaeline, (24.3, 28.7 and 40.6 ng eq./mL) were reached at 2.00-3.33 hours following oral dosing of ipecac syrup. The maximum plasma radioactivity levels of 3H-emetine (2.71, 6.47 and 9.62 ng eq./mL) were reached at 1.08-2.33 hours following ipecac syrup administration. The Cmax values of 3H-cephaeline were followed by a biexponential decrease with half-lives t 1/2(lambda z) of 3.45-9.40 hours. On the other hand, the t 1/2 (lambda z)of 3H-emetine were 65.4-163 hours, which revealed a biexponential decrease. The radioactivity of both tritium-labeled compounds was distrbuted maximally in most tissues at 24 hours. For 3H-cephaeline, the maximum radioactivity levels in tissues were approximately 100-150 times greater than in plasma. For 3H-emetine, the radioactivity levels in tissues were approximately 1000-3000 times greater than in plasma. Tissue radioactivity levels decreased at a substantially slower rate than that observed in plasma. Tissue radioactivity of 3H-emetine decreased more slowly than that of 3H-cephaeline. For 3H-cephaeline, the cumulative biliary excretion of radioactivity was 57.5% at 48 hours. The cumulative urinary and fecal excretion of radioactivity in these rats was 16.5% and 29.1%, respectively, of the dose at 48 hours following dosing. For 3H-emetine, the cumulative biliary excretion of radioactivity was 12.5% at 48 hours. The cumulative urinary and fecal excretion of radioactivity was 9.4% and 34.1%, respectively, of the administered dose at 48 hours. The radioactivity level of 3H-emetine remaining in the carcasses at 48 hours was equivalent to approximately 50% of the dose. A portion of each tritium-labeled compound was subjected to entero-hepatic circulation. Thus, the absorption rate of 3H-cephaeline and 3H-emetine was estimated to be approximately 70% on the basis of the data obtained from excretion studies. There was no difference in the absorption process between these two compounds. However, the difference was admitted in the biliary clearance, which is the main excretion route of both compounds. Delayed excretion of 3H-emetine may be primarily due to its resorption as related to entero-hepatic circulation and tissue retention. This study has determined the absorption, distribution and excretion of 3H-cephaeline and 3H-emetine in rats.

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“…Additionally, Pellini et aI. 13) indicated that cephaeline showed a more potent local stimulatory effect than emetine.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, Pellini et aI. 13) have shown that these side effects occur as a result of specific inflammatory responses along the digestive tract mucosa after oral or parenteral administration of ipecac. Additionally, Pellini et aI.…”

Section: Introductionmentioning

confidence: 99%

Absorption, distribution and excretion of3H-labeled cephaeline- and emetine-spiked ipecac syrup in rats

Asano

Ishihara²,

Wakui³

et al. 2002

Eur. J. Drug Metab. Pharmacokinet.

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“…Copper sulfate has been reported to increase the intestinal content of 5-HT (29). Cephaeline and emetine elicit local irritation on the gastrointestinal mucosa, and the irritation is more potent for cephaeline than for emetine similarly to their emetic activity (30). Therefore, the possibility of local irritation by these active ingredients is undeniable in terms of the TJN-119-induced 5-HT release from EC cells, apart from the mechanism of development via the 5-HT4 receptor.…”

Section: Discussionmentioning

confidence: 99%

Studies for the Emetic Mechanisms of Ipecac Syrup (TJN-119) and Its Active Components in Ferrets: Involvement of 5-Hydroxytryptamine Receptors

Hasegawa

Sasaki

Sadakane

et al. 2002

Japanese Journal of Pharmacology

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ABSTRACT-Ipecac syrup, prepared from a galentical ipecac, contains the nauseant alkaloids cephaeline and emetine. The involvement of receptors and serotonin-and dopamine-metabolizing enzymes in the emesis induced by ipecac syrup and these components was investigated. 1) In ferrets, the selective 5-HT3-receptor antagonist ondansetron (0.5 mg /kg, p.o.) prevented each emesis induced by TJN-119 (0.5 mL /kg, p.o.), cephaeline (0.5 mg /kg, p.o.) and emetine (5.0 mg /kg, p.o.), but the intraperitoneal administration of the selective dopamine D2-receptor antagonist sulpiride failed to significantly suppress the TJN-119, cephaeline and emetine-induced emesis at a dose of 0.1 mg /kg that blocked apomorphine-induced emesis. 2) In the receptor binding assays, cephaeline and emetine had a distinct affinity to 5-HT4 receptor, but no or weak affinity to 5-HT1A, 5-HT3, nicotine, M3, >1, NK1 and D2 receptors. 3) Cephaeline and emetine did not affect activities of metabolic enzymes of 5-HT and dopamine (MAO-A, MAO-B, tryptophan 5-hydroxylase and tyrosine hydroxylase) in vitro. These results suggest that 5-HT3 receptor plays an important role in the emetic action of TJN-119, cephaeline and emetine, and the 5-HT4 receptor may be involved in their mechanisms.

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“…Currently there is great interest in molecular mixed-element oxides incorporating main group elemental oxide fragments such as M(O Ϫ ) 3 (M ϭ B, Al, Ga), MO(O Ϫ ) 3 (M ϭ P), or M(O Ϫ ) 4 (M ϭ Si, Ge, Sn), mainly as a result of potential applications in material science and catalysis. [1,2] In most cases, the preferred valence numbers within these fragments preclude a degree of branching higher than four.…”

Section: Introductionmentioning

confidence: 99%

“…[3] In one case molecular tellurasiloxanes, namely [(Me 2 SiO) 2 ] 3 Te (I), and (Me 3 SiO) 8 Te 2 O 2 (II) [4] were described and in another case a unique mixed-valence Te IV -Te VI species {OTe(C 8 H 8 )[(EtO) 2 PS 2 ]} 6 Te (III) was reported. [5] Here we present the syntheses of the first tellurastannoxanes mer-[(Bu 3 SnO) 3 Te(OH) 3 ] and trans-[(Bu 3 SnO) 2 {CH 2 -(Ph 2 SnO) 2 } 2 Te]. The former compound containing unsubstituted hydroxyl groups has potential as a building block for the preparation of ternary mixed-metal oxides, a class of compounds for which few examples are known.…”

Section: Introductionmentioning

confidence: 99%

The First Well-Defined Tellurastannoxanes: the X-ray Structure oftrans-[(Bu3SnO)2{CH2(Ph2SnO)2}2Te]

Beckmann

Dakternieks

O'Connell

et al. 2002

Eur. J. Inorg. Chem.

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The Pharmacology of Emetin

Cited by 15 publications

References 0 publications

Absorption, distribution and excretion of3H-labeled cephaeline- and emetine-spiked ipecac syrup in rats

Absorption, distribution and excretion of3H-labeled cephaeline- and emetine-spiked ipecac syrup in rats

Studies for the Emetic Mechanisms of Ipecac Syrup (TJN-119) and Its Active Components in Ferrets: Involvement of 5-Hydroxytryptamine Receptors

The First Well-Defined Tellurastannoxanes: the X-ray Structure oftrans-[(Bu3SnO)2{CH2(Ph2SnO)2}2Te]

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