Pharmacokinetic drug interactions with oral haloperidol in adults: dose correction factors from a combined weighted analysis

The impact of pregnancy on the pharmacokinetics of antiseizure medications: A systematic review and meta-analysis of data from 674 pregnancies

OBJECTIVE

Increasing evidence suggests that the physiological changes of pregnancy may impact pharmacokinetics of antiseizure medications (ASM), and this may affect treatment outcomes. The aim of this study was to quantify the pregnancy impact on the ASM pharmacokinetics.

METHODS

A systematic literature search was conducted in PubMed/EMBASE in November 2022 and updated in August 2023 for studies comparing levels of ASM in the same individuals during pregnancy and in the preconception/postpartum period. Alteration ratios between the 3rd trimester and baseline were estimated. We also performed a random-effects meta-analysis calculating between-timepoint differences in mean differences (MDs) and 95% confidence intervals (95%CIs) for dose-adjusted plasma concentrations (C/D ratios). Study quality was assessed using the ClinPK guidelines.

RESULTS

A total of 65 studies investigating 15 ASMs in 674 pregnancies were included. The largest differences were reported for lamotrigine, oxcarbazepine and levetiracetam (alteration ratio 0.42, range 0.07-2.45, 0.42, range 0.08-0.82 and 0.52, range 0.04-2.77 respectively): accordingly, C/D levels were lower in the 3rd trimester for lamotrigine, levetiracetam and the main oxcarbazepine metabolite monohydroxycarbazepine (MD = -12.33 × 10-3, 95%CI = -16.08 to -8.58 × 10-3 (μg/mL)/(mg/day), p < 0.001, MD = -7.16 (μg/mL)/(mg/day), 95%CI = -9.96 to -4.36, p < 0.001, and MD = -4.87 (μg/mL)/(mg/day), 95%CI = -9.39 to -0.35, p = 0.035, respectively), but not for oxcarbazepine (MD = 1.16 × 10-3 (μg/mL)/(mg/day), 95%CI = -2.55 to 0.24 × 10-3, p = 0.10). The quality of studies was acceptable with an average rating score of 11.5.

CONCLUSIONS

Data for lamotrigine, oxcarbazepine (and monohydroxycarbazepine) and levetiracetam demonstrate major changes in pharmacokinetics during pregnancy, suggesting the importance of therapeutic drug monitoring to assist clinicians in optimizing treatment outcomes.

Optimisation of pharmacotherapy in psychiatry through therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests: focus on antipsychotics

BACKGROUND

For psychotic disorders (i.e. schizophrenia), pharmacotherapy plays a key role in controlling acute and long-term symptoms. To find the optimal individual dose and dosage strategy, specialized tools are used. Three tools have been proven useful to personalize drug treatments: therapeutic drug monitoring (TDM) of drug levels, pharmacogenetic testing (PG), and molecular neuroimaging.

METHODS

In these Guidelines, we provide an in-depth review of pharmacokinetics, pharmacodynamics, and pharmacogenetics for 50 antipsychotics. Over 30 international experts in psychiatry selected studies that have measured drug concentrations in the blood (TDM), gene polymorphisms of enzymes involved in drug metabolism, or receptor/transporter occupancies in the brain (positron emission tomography (PET)).

RESULTS

Study results strongly support the use of TDM and the cytochrome P450 (CYP) genotyping and/or phenotyping to guide drug therapies. Evidence-based target ranges are available for titrating drug doses that are often supported by PET findings.

CONCLUSION

All three tools discussed in these Guidelines are essential for drug treatment. TDM goes well beyond typical indications such as unclear compliance and polypharmacy. Despite its enormous potential to optimize treatment effects, minimize side effects and ultimately reduce the global burden of diseases, personalized drug treatment has not yet become the standard of care in psychiatry.

Pharmacokinetics, pharmacodynamics, safety, and tolerability of dopamine-receptor antagonists for the prevention of chemotherapy-induced nausea and vomiting

INTRODUCTION

Dopamine (D)2,3-receptor antagonists (RAs) were the first antiemetics used in the prophylaxis of chemotherapy-induced nausea and vomiting (CINV).

AREAS COVERED

Eight D2,3-RAs, amisulpride, domperidone, droperidol, haloperidol, metoclopramide, metopimazine, olanzapine and prochlorperazine are reviewed focusing on pharmacokinetics, pharmacodynamics, antiemetic effect and side effects.

EXPERT OPINION

Since the introduction of D2,3-RAs, antiemetics such as corticosteroids, 5-hydroxytryptamine (5-HT)3-RAs and neurokinin (NK)1-RAs have been developed. The classical D2,3-RAs are recommended in the prophylaxis of CINV from low emetic risk chemotherapy, but not as a fixed component of an antiemetic regimen for moderately or highly (HEC) emetic risk chemotherapy. D2,3-RAs are also used in patients with breakthrough nausea and vomiting. It should be emphasized, that most of these drugs are not selective for dopamine receptors.The multi-receptor targeting agent, olanzapine, is recommended in the prophylaxis of HEC-induced CINV as part of a four-drug antiemetic regimen, including a 5-HT3-RA, dexamethasone and a NK1-RA. Olanzapine is the most effective agent to prevent chemotherapy-induced nausea.Side effects differ among various D2,3-RAs. Metopimazine and domperidone possess a low risk of extrapyramidal side effects. Domperidone and metoclopramide are prokinetics, whereas metopimazine delays gastric emptying and haloperidol does not influence gastric motility. Many D2,3-RAs increase the risk of prolonged QTc interval; other side effects include sedation and orthostatic hypotension.

Transfer of anticonvulsants and lithium into amniotic fluid, umbilical cord blood & breast milk: A systematic review & combined analysis

OBJECTIVE

Data on the ability of anticonvulsants and lithium to enter fetal and newborn circulation has become increasingly available; here we estimated penetration ratios in a series of matrices from combined samples of pregnant/breastfeeding women treated with anticonvulsants or lithium.

METHODS

We conducted a systematic literature search in PubMed/EMBASE for studies with concentrations of anticonvulsants/lithium from maternal blood, amniotic fluid, umbilical cord blood and/or breast milk. Penetration ratios were calculated by dividing the concentrations in amniotic fluid, umbilical cord plasma or breast milk by the maternal concentrations. When data from multiple studies were available, we calculated combined penetration ratios, weighting studies' mean by study size.

RESULTS

Ninety-one eligible studies for brivaracetam, carbamazepine, clonazepam, ethosuximide, gabapentin, lacosamide, lamotrigine, levetiracetam, lithium, oxcarbazepine, perampanel, phenobarbital, phenytoin, pregabalin, primidone, topiramate, valproate, vigabatrin and zonisamide were identified. For amniotic fluid, the highest penetration ratios were estimated for levetiracetam (mean 3.56, range 1.27-5.85, n = 2) and lowest for valproate (mean 0.11, range 0.02-1.02, n = 57). For umbilical cord plasma, oxcarbazepine had the highest ratio (mean 1.59, range 0.11-4.33, n = 12) with clonazepam having the lowest (mean 0.55, range 0.52-0.59, n = 2). For breast milk, the highest ratios were observed for oxcarbazepine (mean 3.75, range 0.5-7.0, n = 2), whereas the lowest were observed for valproate (mean 0.04, range 0.01-0.22, n = 121).

DISCUSSION

We observed substantial variability between anticonvulsants and lithium regarding their ability to enter fetal/newborn circulation. Assessing concentrations of anticonvulsants and lithium in maternal samples can provide a surrogate of fetal/infant exposure, although patterns of concentration-dependent effects for maternal/neonatal safety are lacking.