TY  - JOUR
AU  - Panić, Bojana
AU  - Jovanović, Marija
AU  - Lukić, Vera
AU  - Vučićević, Katarina
AU  - Miljković, Branislava
AU  - Milovanović, Srđan
PY  - 2023
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/5040
AB  - Purpose: The goal of the study was to examine clozapine (CLZ) and norclozapine (NCLZ) therapeutic drug monitoring (TDM) data and associated sources of pharmacokinetic variability, particularly the impact of valproic acid (VPA) use. Methods: This study included 126 patients with psychiatric disorders on mono- or co-therapy with CLZ. Patients’ data during routine TDM were collected retrospectively from clinical records. The descriptive and statistical analysis was computed using IBM SPSS Statistics software (version 22, NY, USA). Multiple linear regression, based on the last observations, was used to assess correlation between demographic characteristics, life habits and co-therapy with dose-corrected serum levels (C/D) of CLZ and NCLZ, as well as CLZ/NCLZ. Results: A total of 295 CLZ concentrations were measured in 126 patients, with a mean of 275.5 ± 174.4 µg/L, while 124 NCLZ concentrations were determined in 74 patients, with a mean of 194.6 ± 149.8 µg/L. A statistically significant effect on ln-transformed CLZ C/D was confirmed for sex and smoking, whereas sex, smoking and VPA therapy were associated with ln-transformed NCLZ C/D. According to the final models, lower values of NCLZ C/D for about 45.9% can be expected in patients receiving VPA. Concomitant use of VPA was the only factor detected to contribute in CLZ/NCLZ variability. Conclusion: The results of this study may help clinicians interpret TDM data and optimize CLZ dosing regimens, especially in patients concomitantly treated with VPA. Our results show that VPA primarily decreases NCLZ levels, while alteration of the parent drug is not statistically significant.
PB  - Springer
T2  - European Journal of Clinical Pharmacology
T1  - Association of clozapine and norclozapine levels with patient and therapy characteristics—focus on interaction with valproic acid
DO  - 10.1007/s00228-023-03569-2
ER  - 

@article{
author = "Panić, Bojana and Jovanović, Marija and Lukić, Vera and Vučićević, Katarina and Miljković, Branislava and Milovanović, Srđan",
year = "2023",
abstract = "Purpose: The goal of the study was to examine clozapine (CLZ) and norclozapine (NCLZ) therapeutic drug monitoring (TDM) data and associated sources of pharmacokinetic variability, particularly the impact of valproic acid (VPA) use. Methods: This study included 126 patients with psychiatric disorders on mono- or co-therapy with CLZ. Patients’ data during routine TDM were collected retrospectively from clinical records. The descriptive and statistical analysis was computed using IBM SPSS Statistics software (version 22, NY, USA). Multiple linear regression, based on the last observations, was used to assess correlation between demographic characteristics, life habits and co-therapy with dose-corrected serum levels (C/D) of CLZ and NCLZ, as well as CLZ/NCLZ. Results: A total of 295 CLZ concentrations were measured in 126 patients, with a mean of 275.5 ± 174.4 µg/L, while 124 NCLZ concentrations were determined in 74 patients, with a mean of 194.6 ± 149.8 µg/L. A statistically significant effect on ln-transformed CLZ C/D was confirmed for sex and smoking, whereas sex, smoking and VPA therapy were associated with ln-transformed NCLZ C/D. According to the final models, lower values of NCLZ C/D for about 45.9% can be expected in patients receiving VPA. Concomitant use of VPA was the only factor detected to contribute in CLZ/NCLZ variability. Conclusion: The results of this study may help clinicians interpret TDM data and optimize CLZ dosing regimens, especially in patients concomitantly treated with VPA. Our results show that VPA primarily decreases NCLZ levels, while alteration of the parent drug is not statistically significant.",
publisher = "Springer",
journal = "European Journal of Clinical Pharmacology",
title = "Association of clozapine and norclozapine levels with patient and therapy characteristics—focus on interaction with valproic acid",
doi = "10.1007/s00228-023-03569-2"
}

Panić, B., Jovanović, M., Lukić, V., Vučićević, K., Miljković, B.,& Milovanović, S.. (2023). Association of clozapine and norclozapine levels with patient and therapy characteristics—focus on interaction with valproic acid. in European Journal of Clinical Pharmacology
Springer..
https://doi.org/10.1007/s00228-023-03569-2

Panić B, Jovanović M, Lukić V, Vučićević K, Miljković B, Milovanović S. Association of clozapine and norclozapine levels with patient and therapy characteristics—focus on interaction with valproic acid. in European Journal of Clinical Pharmacology. 2023;.
doi:10.1007/s00228-023-03569-2 .

Panić, Bojana, Jovanović, Marija, Lukić, Vera, Vučićević, Katarina, Miljković, Branislava, Milovanović, Srđan, "Association of clozapine and norclozapine levels with patient and therapy characteristics—focus on interaction with valproic acid" in European Journal of Clinical Pharmacology (2023),
https://doi.org/10.1007/s00228-023-03569-2 . .

TY  - CONF
AU  - Panić, Bojana
AU  - Jovanović, Marija
AU  - Lukić, Vera
AU  - Bulat, Zorica
AU  - Vučićević, Katarina
AU  - Miljković, Branislava
AU  - Milovanović, Srđan
PY  - 2022
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/4507
AB  - The atypical antipsychotic clozapine (CLZ) is primarily used for the treatment-
resistant schizophrenia. Due to low therapeutic index and high pharmacokinetic variability,
therapeutic drug monitoring (TDM) is highly recommended (1). The aim of this retrospective
study was to analyze TDM data of CLZ and its active metabolite norclozapine (NCLZ) in adult
patient with schizophrenia. The study included CLZ TDM data obtained from 69 patients (22-
67 years) treated at the Clinic for Psychiatry, Clinical Center of Serbia, while NCLZ data were
available from 43 patients. Serum concentrations were determined at the Institute of
Forensic Medicine, Belgrade, Serbia using liquid chromatography with tandem mass
spectrometry (LC‐MS/MS). Statistical analysis was performed by SPSS software® (version
18). The daily doses of CLZ ranged between 37.5 and 600 mg. The mean value of CLZ and
NCLZ levels were 0.285 ± 0.174 mg/L and 0.189 ± 0.132 mg/L, respectively. 73.06% and
26.83% of measured CLZ and NCLZ concentrations were outside reference range (mostly
below), respectively. Significant positive correlation (p<0.05) was observed between daily
dose and CLZ levels, as well as between dose and NCLZ levels. Significant correlations of dose
and CLZ levels were confirmed in males and females, smokers and nonsmokers, separately.
Parent drug and metabolite levels varied 13 and 16-fold in patients receiving 300 mg/day,
respectively. The results indicate considerable variability in CLZ and NCLZ concentrations in
adult patients with schizophrenia, and positive association with dose. Further multivariate
analysis is required to assess, in addition to dose, potential influences of other patient and
co-therapy factors.
AB  - Atipični antipsihotik klozapin (clozapine, CLZ) se primarno koristi kod shizofrenije
rezistentne na terapiju. Zbog niskog terapijskog indeksa i velike farmakokinetičke
varijabilnosti, terapijsko prać enje lekova (therapeutic drug monitoring, TDM) se preporučuje
(1). Cilj ovog retrospektivnog istraživanja je bio ispitivanje TDM podataka o CLZ i njegovom
aktivnom metabolitu norklozapinu (norclozapine, NCLZ) kod odraslih pacijenata sa
shizofrenijom. Studija je obuhvatila TDM podatke o CLZ dobijene od 69 pacijenata (22-67
godina) lečenih na Klinici za psihijatriju Kliničkog centra Srbije, dok su podaci za NCLZ bili
dostupni od 43 pacijenta. Koncentracije u serumu su merene na Institutu za sudsku
medicinu, Beograd, Srbija tečnom hromatografijom sa tandem masenom spektrometrijom
(LC‐MS/MS). Statistička analiza je izvršena pomoć u softvera SPSS® (verzija 18). Dnevne doze
CLZ kretale su se između 37,5 i 600 mg. Srednja vrednost je bila 0,285 ± 0,174 mg/L za CLZ i
0,189 ± 0,132 mg/L za NCLZ. 73,06% i 26,83% izmerenih koncentracija CLZ i NCLZ bile su
izvan referentnog opsega (uglavnom ispod), respektivno. Detektovana je pozitivna korelacija
(p<0,05) između dnevne doze i nivoa CLZ, kao i doze i nivoa NCLZ. Značajna korelacija doze i
nivoa CLZ je potvrđena i pri odvojenom ispitivanju kod muškaraca, žena, pušača i nepušača.
Nivoi leka i metabolita varirali su 13 i 16 puta kod pacijenata koji su uzimali 300 mg/dan,
respektivno. Rezultati ukazuju na značajnu varijabilnost u koncentracijama CLZ i NCLZ kod
odraslih pacijenata sa shizofrenijom i pozitivnu povezanost sa dozom. Potrebna je dalja
multivarijantna analiza da bi se procenili, pored doze, potencijalni uticaji karakteristika
pacijenata i kombinovane terapije.
PB  - Savez farmaceutskih udruženja Srbije (SFUS)
C3  - Arhiv za farmaciju
T1  - Analysis of clozapine and norclozapine concentrations in adult patients with schizophrenia
T1  - Analiza koncentracija klozapina i norklozapina kod odraslih pacijenata sa shizofrenijom
VL  - 72
IS  - 4 suplement
SP  - S225
EP  - S226
UR  - https://hdl.handle.net/21.15107/rcub_farfar_4507
ER  - 

@conference{
author = "Panić, Bojana and Jovanović, Marija and Lukić, Vera and Bulat, Zorica and Vučićević, Katarina and Miljković, Branislava and Milovanović, Srđan",
year = "2022",
abstract = "The atypical antipsychotic clozapine (CLZ) is primarily used for the treatment-
resistant schizophrenia. Due to low therapeutic index and high pharmacokinetic variability,
therapeutic drug monitoring (TDM) is highly recommended (1). The aim of this retrospective
study was to analyze TDM data of CLZ and its active metabolite norclozapine (NCLZ) in adult
patient with schizophrenia. The study included CLZ TDM data obtained from 69 patients (22-
67 years) treated at the Clinic for Psychiatry, Clinical Center of Serbia, while NCLZ data were
available from 43 patients. Serum concentrations were determined at the Institute of
Forensic Medicine, Belgrade, Serbia using liquid chromatography with tandem mass
spectrometry (LC‐MS/MS). Statistical analysis was performed by SPSS software® (version
18). The daily doses of CLZ ranged between 37.5 and 600 mg. The mean value of CLZ and
NCLZ levels were 0.285 ± 0.174 mg/L and 0.189 ± 0.132 mg/L, respectively. 73.06% and
26.83% of measured CLZ and NCLZ concentrations were outside reference range (mostly
below), respectively. Significant positive correlation (p<0.05) was observed between daily
dose and CLZ levels, as well as between dose and NCLZ levels. Significant correlations of dose
and CLZ levels were confirmed in males and females, smokers and nonsmokers, separately.
Parent drug and metabolite levels varied 13 and 16-fold in patients receiving 300 mg/day,
respectively. The results indicate considerable variability in CLZ and NCLZ concentrations in
adult patients with schizophrenia, and positive association with dose. Further multivariate
analysis is required to assess, in addition to dose, potential influences of other patient and
co-therapy factors., Atipični antipsihotik klozapin (clozapine, CLZ) se primarno koristi kod shizofrenije
rezistentne na terapiju. Zbog niskog terapijskog indeksa i velike farmakokinetičke
varijabilnosti, terapijsko prać enje lekova (therapeutic drug monitoring, TDM) se preporučuje
(1). Cilj ovog retrospektivnog istraživanja je bio ispitivanje TDM podataka o CLZ i njegovom
aktivnom metabolitu norklozapinu (norclozapine, NCLZ) kod odraslih pacijenata sa
shizofrenijom. Studija je obuhvatila TDM podatke o CLZ dobijene od 69 pacijenata (22-67
godina) lečenih na Klinici za psihijatriju Kliničkog centra Srbije, dok su podaci za NCLZ bili
dostupni od 43 pacijenta. Koncentracije u serumu su merene na Institutu za sudsku
medicinu, Beograd, Srbija tečnom hromatografijom sa tandem masenom spektrometrijom
(LC‐MS/MS). Statistička analiza je izvršena pomoć u softvera SPSS® (verzija 18). Dnevne doze
CLZ kretale su se između 37,5 i 600 mg. Srednja vrednost je bila 0,285 ± 0,174 mg/L za CLZ i
0,189 ± 0,132 mg/L za NCLZ. 73,06% i 26,83% izmerenih koncentracija CLZ i NCLZ bile su
izvan referentnog opsega (uglavnom ispod), respektivno. Detektovana je pozitivna korelacija
(p<0,05) između dnevne doze i nivoa CLZ, kao i doze i nivoa NCLZ. Značajna korelacija doze i
nivoa CLZ je potvrđena i pri odvojenom ispitivanju kod muškaraca, žena, pušača i nepušača.
Nivoi leka i metabolita varirali su 13 i 16 puta kod pacijenata koji su uzimali 300 mg/dan,
respektivno. Rezultati ukazuju na značajnu varijabilnost u koncentracijama CLZ i NCLZ kod
odraslih pacijenata sa shizofrenijom i pozitivnu povezanost sa dozom. Potrebna je dalja
multivarijantna analiza da bi se procenili, pored doze, potencijalni uticaji karakteristika
pacijenata i kombinovane terapije.",
publisher = "Savez farmaceutskih udruženja Srbije (SFUS)",
journal = "Arhiv za farmaciju",
title = "Analysis of clozapine and norclozapine concentrations in adult patients with schizophrenia, Analiza koncentracija klozapina i norklozapina kod odraslih pacijenata sa shizofrenijom",
volume = "72",
number = "4 suplement",
pages = "S225-S226",
url = "https://hdl.handle.net/21.15107/rcub_farfar_4507"
}

Panić, B., Jovanović, M., Lukić, V., Bulat, Z., Vučićević, K., Miljković, B.,& Milovanović, S.. (2022). Analysis of clozapine and norclozapine concentrations in adult patients with schizophrenia. in Arhiv za farmaciju
Savez farmaceutskih udruženja Srbije (SFUS)., 72(4 suplement), S225-S226.
https://hdl.handle.net/21.15107/rcub_farfar_4507

Panić B, Jovanović M, Lukić V, Bulat Z, Vučićević K, Miljković B, Milovanović S. Analysis of clozapine and norclozapine concentrations in adult patients with schizophrenia. in Arhiv za farmaciju. 2022;72(4 suplement):S225-S226.
https://hdl.handle.net/21.15107/rcub_farfar_4507 .

Panić, Bojana, Jovanović, Marija, Lukić, Vera, Bulat, Zorica, Vučićević, Katarina, Miljković, Branislava, Milovanović, Srđan, "Analysis of clozapine and norclozapine concentrations in adult patients with schizophrenia" in Arhiv za farmaciju, 72, no. 4 suplement (2022):S225-S226,
https://hdl.handle.net/21.15107/rcub_farfar_4507 .