This international guideline proposes improving clozapine package inserts worldwide by using ancestry-based dosing and titration. Adverse drug reaction (ADR) databases suggest that clozapine is the third most toxic drug in the United States (US), and it produces four times higher worldwide pneumonia mortality than that by agranulocytosis or myocarditis. For trough steady-state clozapine serum concentrations, the therapeutic reference range is narrow, from 350 to 600 ng/mL with the potential for toxicity and ADRs as concentrations increase. Clozapine is mainly metabolized by CYP1A2 (female non-smokers, the lowest dose; male smokers, the highest dose). Poor metabolizer status through phenotypic conversion is associated with co-prescription of inhibitors (including oral contraceptives and valproate), obesity, or inflammation with C-reactive protein (CRP) elevations. The Asian population (Pakistan to Japan) or the Americas’ original inhabitants have lower CYP1A2 activity and require lower clozapine doses to reach concentrations of 350 ng/mL. In the US, daily doses of 300–600 mg/day are recommended. Slow personalized titration may prevent early ADRs (including syncope, myocarditis, and pneumonia). This guideline defines six personalized titration schedules for inpatients: 1) ancestry from Asia or the original people from the Americas with lower metabolism (obesity or valproate) needing minimum therapeutic dosages of 75–150 mg/day, 2) ancestry from Asia or the original people from the Americas with average metabolism needing 175–300 mg/day, 3) European/Western Asian ancestry with lower metabolism (obesity or valproate) needing 100–200 mg/day, 4) European/Western Asian ancestry with average metabolism needing 250–400 mg/day, 5) in the US with ancestries other than from Asia or the original people from the Americas with lower clozapine metabolism (obesity or valproate) needing 150–300 mg/day, and 6) in the US with ancestries other than from Asia or the original people from the Americas with average clozapine metabolism needing 300–600 mg/day. Baseline and weekly CRP monitoring for at least four weeks is required to identify any inflammation, including inflammation secondary to clozapine rapid titration.

The results of the present study documented elevations of GABA levels both in the mPFC and, for the first time, in the dorsal caudate of antipsychotic-naïve patients with FEP, which normalized in both regions following 4 weeks of antipsychotic treatment.

Praziquantel (PZQ) is an important chiral active pharmaceutical ingredient for the treatment of gastrointestinal parasites, which is commercially available only in the form of its racemate. In this article, on the basis of co-crystallization experiments a convenient two-step protocol for the chiral resolution of RS-PZQ is described. Screening experiments with RS-PZQ using the liquid-assisted grinding technique revealed the formation of a diastereomeric co-crystal pair with L-malic acid (L-MA) of the compositions R-PZA:L-MA and S-PZQ:L-MA. Both co-crystals have been examined by single-crystal X-ray diffraction analysis, revealing similar unit cell parameters but differences in the supramolecular organization. Particularly the analysis of the hydrogen bonding patterns indicated overall stronger intermolecular interactions in the case of R-PZA:L-MA, which was confirmed by thermogravimetric−differential scanning calorimetry analysis giving a substantial difference in the melting point when compared to S-PZA:L-MA. After synthesis of R-and S-PZQ in enantiomerically pure form for the selective preparation of both R-PZA:L-MA and S-PZQ:L-MA, comparative solubilization experiments were carried out. Since significant variations in the solubility were found in some solvents, a procedure could be established allowing for the separation of R-PZA:L-MA by fractional crystallization. In a subsequent reaction step, the biologically active enantiomer R-PZQ was liberated from the co-crystal in the form of its hemihydrate by stirring with water. Comparison of the intrinsic dissolution rates for RS-PZQ, R-PZA•0.5H 2 O, and R-PZA:L-MA indicated that the co-crystalline phase exhibits a significantly larger rate constant than praziquantel in its enantiomerically pure form or as a racemate.

The PM frequency of CYP2D6 in the population studied was 10%, which is very similar to Spanish Caucasians. The observed frequency of the CYP2D6 alleles tested was unique for the Mexican Mestizo sample analyzed, and in accordance to the Caucasian, Asian and African admixture in this population.