Pharmacokinetic Variability of Sulthiame: The Impact of Age, Drug-Drug Interactions, and Biochemical Markers of Toxicity in Patients with Epilepsy.

PURPOSE: Sulthiame is an antiseizure medication increasingly used for epilepsy. The aim of this study was to investigate the pharmacokinetic variability of sulthiame in children and adults with epilepsy with respect to age, comedication, dose, serum concentration, and biochemical markers of toxicity in a clinical setting. METHOD: Retrospective quantitative data from the therapeutic drug monitoring (TDM) database at the Section for Clinical Pharmacology, the National Center for Epilepsy, Norway (2015-2021), were used. RESULTS: TDM data from 326 patients (127 female/199 male) were included [mean age, 11.4 (range 2-44) years; mean weight, 41 (range 14-109) kg]. Interindividual pharmacokinetic variability in the concentration/(dose/body weight) (C/(D/kg)) ratio was 16-fold; intraindividual variability was up to 8-fold (coefficient of variation = 10%-78%). Young children (younger than 6 years) had a significantly lower C/(D/kg) ratio than older age groups ( P < 0.05). Various comedications did not significantly affect the C/(D/kg) ratio, possibly owing to the small sample size. However, CYP2C19-mediated inhibition by sulthiame was indicated because patients using clobazam and sulthiame (n = 28) had a 3.5-fold higher N-desmethylclobazam C/(D/kg) ratio than those using neutral comedication (n = 45; P < 0.001). Patients with pH values below the adjusted normal range (7.32-7.42; n = 15) had a 33% higher sulthiame concentration than those with normal pH values (n = 22; P < 0.05). Blood gas measurements, especially pH, may serve as markers of toxicity and can be used in combination with clinical data when toxicity is suspected. CONCLUSIONS: This study revealed the extensive intraindividual and interindividual pharmacokinetic variability of sulthiame, with age as a contributing factor. Sulthiame has clinically relevant interactions with clobazam. The use of TDM and pH as a biochemical marker may contribute to individualized and safe sulthiame treatment.

Effect and tolerability of perampanel in patients with drug-resistant epilepsy.

OBJECTIVE: Perampanel is one of the most recently approved antiseizure medications. The aim of the present study was to assess clinical efficacy and tolerability, in combination with pharmacokinetic variability, of perampanel treatment in patients at a tertiary referral center for epilepsy. METHODS: We performed a retrospective observational study of patients given perampanel as adjunctive treatment in the period January 2013 - February 2019 at the National Center for Epilepsy at Oslo University Hospital, Norway. RESULTS: Clinical data were available for 175 mainly adult patients with drug-resistant epilepsy with mean treatment duration of 16.1 months. We found that 23% (40 patients) were responders (i.e., achieving more than 50% reduction in seizure frequency), four of whom became seizure free, 29% (51 patients) experienced a modest effect, whereas for 29% (50 patients) perampanel had no seizure-reducing effect. A paradoxical effect, with seizure aggravation, was reported in 9% (15 patients). The responder rate was significantly higher in those with slow vs. fast dosage titration. Logistic regression analysis showed better efficacy among those with generalized vs. those with focal epilepsy. Adverse effects were reported by 135 patients (77%), ranging from mild (34%), to moderate (41%) and severe (2%). In 55 patients (41%), these adverse effects resulted in discontinuation of treatment with perampanel. The most frequent adverse effects were psychiatric symptoms (34%), dizziness (31%), and sleepiness (26%). Of the 31 patients for whom serum concentration measurements were available, the mean daily perampanel dose was 6.3 mg (SD 3.0), with a mean serum concentration at steady state of 1.03 µmol/L (range: 0.15-3.59 µmol/L). There were pronounced differences between patients, as demonstrated by a 12-fold variability in the range of concentration/dose (C/D)-ratios (0.06 to 0.69 µmol/L/mg), where enzyme inducers contributed. CONCLUSION: Our results demonstrate that perampanel had a modest seizure-reducing effect in this very treatment-resistant patient group. Predictors of treatment success were generalized epilepsy and slow dosage titration. In patients without a history of psychiatric problems, clinicians could consider increasing dose of perampanel beyond 6 mg daily, taking co-medication and serum concentrations into account.

Antibiotic dosing ­ theory and practice. / Antibiotikadosering ­ teori og praksis.

Antimicrobial resistance constitutes one of the most serious threats to public health. Few new antimicrobial drugs are being developed, and the problems of resistance are increasing. Rational use of existing antimicrobials is therefore of growing importance. Basing the use of antimicrobial drugs on their pharmokinetic and pharmacodynamic properties will most often provide a better therapeutic effect and may also help reduce resistance and adverse effects.

Detection Time of Oxazepam and Zopiclone in Urine and Oral Fluid after Experimental Oral Dosing.

Data from previous experimental studies on the detection time of oxazepam and zopiclone in biological matrices are limited. The aim of this study was to examine the detection time in urine and oral fluid after single oral doses of oxazepam and zopiclone. Ten healthy volunteers received 25 mg of oxazepam in the evening of Day 1 and 7.5 mg of zopiclone in the evening of Day 3. Urine and oral fluid samples were collected twice daily for 9 days, with an additional sampling the day after ingestion of zopiclone. A total of 19 samples of both urine and oral fluid from each participant were analyzed using fully validated chromatographic methods. The median detection time for oxazepam was 91 h (range 73-108) in urine and 67 h (range 50-98) in oral fluid. The median detection time for zopiclone in urine was 49 h (range 25-98) and 59 h (range 48-146) in oral fluid. The metabolite zopiclone N-oxide showed a detection time of 36 h (range 25-84) in urine. The area under the concentration-time curve (AUCTotal) in urine corrected for creatinine was 150 µmol/L/mmol/L*h (range 105-216) for oxazepam and 1.60 µmol/L/mmol/L*h (range 0.79-4.53) for zopiclone. In oral fluid, the AUCtotal was 673 nmol/L*h (range 339-1,316) for oxazepam and 2,150 nmol/L*h (range 493-4,240) for zopiclone. In conclusion, oxazepam can be detected longer in urine than in oral fluid, while zopiclone can be detected longer in oral fluid than in urine. The high AUCTotal for zopiclone in oral fluid shows that the transfer into oral fluid is significant. In certain individuals the detection time of zopiclone in oral fluid is long. These results can be helpful when interpreting drug testing analyzes.

An Experimental Study of Diazepam and Alprazolam Kinetics in Urine and Oral Fluid Following Single Oral Doses.

Benzodiazepines are commonly seen in samples submitted for drug testing of patients, people involved in child welfare cases, work-place drug testing, as well as in drug-facilitated assaults. Limited previous experimental studies are available regarding the excretion of benzodiazepines in urine and oral fluid. The aim of this study was to investigate the concentrations of diazepam and alprazolam in oral fluid and urine for up to 2 weeks after ingestion of a single oral dose in healthy volunteers. A total of 11 healthy volunteers ingested 10 mg diazepam at the start of the study and 0.5 mg alprazolam on Day 3 of the study. A total number of 10 oral fluid samples and 17 urine samples were collected from each participant. The samples were analyzed by liquid chromatography with tandem mass spectroscopy and ultra-high performance liquid chromatography tandem mass spectrometry methods. The median detection time was 252 h for the longest detected diazepam metabolite in urine (oxazepam, range 203-322) and 132 h in oral fluid (N-desmethyldiazepam, range 109-136). For alprazolam, the median detection time was 36 h (metabolite α-OH-alprazolam, range 26-61) in urine and 26 h (alprazolam, range 4-37) in oral fluid. These results show that detection times are only 36 h for alprazolam in urine after intake of a single therapeutic oral dose. For diazepam in urine, detection times were 11 days. Detection times were generally shorter in oral fluid compared to urine. The results could be helpful in the interpretation of diazepam or alprazolam findings in drug testing cases involving urine or oral fluid.

Life satisfaction and resilience in medical school--a six-year longitudinal, nationwide and comparative study.

BACKGROUND: This study examined the relationship between life satisfaction among medical students and a basic model of personality, stress and coping. Previous studies have shown relatively high levels of distress, such as symptoms of depression and suicidal thoughts in medical undergraduates. However despite the increased focus on positive psychological health and well-being during the past decades, only a few studies have focused on life satisfaction and coping in medical students. This is the first longitudinal study which has identified predictors of sustained high levels of life satisfaction among medical students. METHODS: This longitudinal, nationwide questionnaire study examined the course of life satisfaction during medical school, compared the level of satisfaction of medical students with that of other university students, and identified resilience factors. T-tests were used to compare means of life satisfaction between and within the population groups. K-means cluster analyses were applied to identify subgroups among the medical students. Analysis of Variance (ANOVA) and logistic regression analyses were used to compare the subgroups. RESULTS: Life satisfaction decreased during medical school. Medical students were as satisfied as other students in the first year of study, but reported less satisfaction in their graduation year. Medical students who sustained high levels of life satisfaction perceived medical school as interfering less with their social and personal life, and were less likely to use emotion focused coping, such as wishful thinking, than their peers. CONCLUSION: Medical schools should encourage students to spend adequate time on their social and personal lives and emphasise the importance of health-promoting coping strategies.