1.Complexation of lappaconitine with glycyrrhizic acid: stability and reactivity studies.
Polyakov NE;Khan VK;Taraban MB;Leshina TV;Salakhutdinov NF;Tolstikov GA J Phys Chem B. 2005 Dec 29;109(51):24526-30.
NMR and UV-vis spectroscopy have been used to study the complexation of antiarrhythmic alkaloid lappaconitine with an efficient complexing agent from licorice, glycyrrhizic acid, which is known to profoundly influence the therapeutic activity of the alkaloid in the complex. In MeOH, DMSO, or aqueous solutions, lappaconitine has been shown to form a stable complex with glycyrrhizic acid with 1:1 stoichiometry over a broad concentration range from 1 microM to 300 microM. The stability constant K(11) equals 2.0 x 10(5) M(-1) in aqueous solution. A similar complex of lappaconitine hydrobromide--the pharmaceutical formulation used in the treatment of arrhythmia--is 2 orders of magnitude less stable than pure lappaconitine. A notable decrease in the rate of the photoinduced electron-transfer reaction between lappaconitine in a complex with glycyrrhizic acid and tyrosine allows the suggestion of an explicit interrelation between the suppressed chemical reactivity of the bound alkaloid and the changes of its therapeutic efficiency.
2.[The Study of Evidence Base for the Use of Lappaconitine Hydrobromide in Patients With Atrial Fibrillation].
Erlikh AD Kardiologiia. 2016 Mar;56(3):48-53.
Lappaconitine Hydrobromide (LH, allapinin) has been included by authors of National Guidelines on Diagnosis and Treatment of Atrial Fibrillation (AF), 2012 in the number of medications recommended for use in patients with AF for rhythm control. Moreover, LH is also included into the List of Vital and Essential Medicinal Drugs (VEMD) 2015. However, LH is not mentioned in corresponding guidelines of the European Society of Cardiology (ESC). Aim of the present review was to explore evidence base underlining use of LH in the context of AF and to understand reason for LH-related discrepancy between European and domestic guidelines.;RESULTS: ;Literature search has indicated that efficacy of LH was assessed only in small open studies. None of prospective trials included more than 100 patients. For more than 25 years of presence on the market slightly more than 400 patients were administered LH in clinical studies. In the only trial, designated as randomized number of participants (only men younger than 60 years) was small and the comparator was quinidine that presently is not used for maintenance of sinus rhythm in AF. Another study referenced in domestic guidelines on management of AF was observational and not intended for comparison of antiarrhythmic activity of drugs.
3.Pharmacokinetic study of lappaconitine hydrobromide in mice by LC-MS.
Wang Q;Li ZJ;Sun L;Gao LY;Li MH;Hao JJ;Zhang X;Sun YM Yao Xue Xue Bao. 2011 Apr;46(4):432-7.
A high sensitive and rapid method was developed for the analysis of lappaconitine in mouse plasma using liquid chromatography coupled to mass spectrometry (LC-MS). Detection was performed by positive ion electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode, monitoring the transitions m/z 585 --> m/z 535 and m/z 356 --> m/z 192, for the quantification of lappaconitine and tetrahydropalmatine (internal standard, IS), respectively. The method was linear over the concentration range of 3.0-2000.0 ng x mL(-1). The lower limit of quantification was 3.0 ng x mL(-1). Intra- and inter-run precisions (RSD) were both less than 9.9% and accuracy (RE) within +/- 4.8%. After single intravenous injections of lappaconitine hydrobromide at 1.0, 2.0 and 4.0 mg x kg(-1), the elimination half-lives (t(1/2)) were 0.47, 0.48 and 0.49 h, and the areas under the curve (AUC(0-t)) were 55.5, 110.5 and 402.9 ng x h x mL(-1), separately. The pharmacokinetic profile of lappaconitine was linear at relatively lower dose levels (1.0-2.0 mg x kg(-1)). When the dose increased farther to 4.0 mg x kg(-1), the Vz and CL decreased, and the increase fold of the AUC was much larger than that of the dose.