Metabolism of anxiolytics and hypnotics: benzodiazepines, buspirone, zoplicone, and zolpidem

Selective Extraction of Diazepam and Its Metabolites from Urine Samples by a Molecularly Imprinted Solid-Phase Extraction (MISPE) Method

In this research, a molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using oxazepam (OZ) as a template molecule and was subsequently applied as a selective sorbent for the extraction of diazepam (DZP) and its metabolites in urine samples using an SPE cartridge. OZ, temazepam (TZ), nordiazepam (NZ) and DZP were analyzed in the final extracts by high-performance liquid chromatography with diode array detection (HPLC-DAD). The SPE extraction steps were optimized, and the evaluation of an imprinting factor was carried out. The selectivity of the method for OZ versus structurally related benzodiazepines (BZDs), such as bromazepam (BRZ), tetrazepam (TTZ) and halazepam (HZ), was investigated. Under the optimum conditions, the proposed methodology provided good linearity in the range of 10-1500 ng/mL, with limit of detection values between 13.5 and 21.1 ng/mL and recovery levels for DZP and its metabolites from 89.0 to 93.9% (RSD ≤ 8%) at a concentration level of 1000 ng/mL. The proposed method exhibited good selectivity, precision and accuracy and was applied to the analysis of urine samples from a real case of DZP intake.

Concordance between controlled substance receipt and post-mortem toxicology in opioid-detected overdose deaths: A statewide analysis

BACKGROUND

Opioid overdoses are a leading cause of preventable death in the United States. There is limited research linking decedents' receipt of controlled substances and presence of controlled substances on post-mortem toxicology (PMT).

METHODS

We linked data on opioid-detected deaths in Connecticut between May 3, 2016, and December 31, 2017 from the Office of the Chief Medical Examiner, Department of Consumer Protection, and Department of Mental Health and Addiction Services. Exposure was defined as receipt of an opioid or benzodiazepine prescription within 90 days prior to death. Our primary outcome was concordance between medication received and metabolites in PMT.

RESULTS

Our analysis included 1412 opioid-detected overdose deaths. 47 % received an opioid or benzodiazepine 90 days prior to death; 36 % received an opioid and 27 % received a benzodiazepine. Concordance between receipt of an opioid or benzodiazepine and its presence in PMT was observed in 30 % of opioid-detected deaths. Concordance with an opioid was present in 17 % of opioid-detected deaths and concordance with a benzodiazepine was present in 21 % of opioid-detected deaths. Receipt of an opioid or benzodiazepine and concordance with PMT were less common in fentanyl or heroin-detected deaths and more common in pharmaceutical opioid-detected deaths.

DISCUSSION

Our results suggest medically supplied opioids and benzodiazepines potentially contributed to a substantial number, though minority, of opioid-detected deaths during the study period. Efforts to reduce opioid and benzodiazepine prescribing may reduce risk of opioid-detected deaths in this group, but other approaches will be needed to address most opioid-detected deaths that involved non-pharmaceutical opioids.

Pharmacologic predictors of benzodiazepine response trajectory in anxiety disorders: a Bayesian hierarchical modeling meta-analysis

BACKGROUND

Despite frequent benzodiazepine use in anxiety disorders, the trajectory and magnitude of benzodiazepine response and the effects of benzodiazepine potency, lipophilicity, and dose on improvement are unknown.

METHODS

We performed a meta-analysis using weekly symptom severity data from randomized, parallel group, placebo-controlled trials of benzodiazepines in adults with anxiety disorders. Response was modeled for the standardized change in continuous measures of anxiety using a Bayesian hierarchical model. Change in anxiety was evaluated as a function of medication, disorder, time, potency, lipophilicity, and standardized dose and compared among benzodiazepines.

RESULTS

Data from 65 trials (73 arms, 7 medications, 7110 patients) were included. In the logarithmic model of response, treatment effects emerged within 1 week of beginning treatment (standardized benzodiazepine-placebo difference = -0.235 ± 0.024, CrI: -0.283 to -0.186, P < .001) and placebo response plateaued at week 4. Doses <6 mg per day (lorazepam equivalents) produced faster and larger improvement than higher doses (P = .039 for low vs medium dose and P = .005 for high vs medium dose) and less lipophilic benzodiazepines (beta = 0.028 ± 0.013, P = .030) produced a greater response over time. Relative to the reference benzodiazepine (lorazepam), clonazepam (beta = -0.217 ± 0.95, P = .021) had a greater trajectory/magnitude of response (other specific benzodiazepines did not statistically differ from lorazepam).

CONCLUSIONS

In adults with anxiety disorders, benzodiazepine-related improvement emerges early, and the trajectory and magnitude of improvement is related to dose and lipophilicity. Lower doses and less lipophilic benzodiazepines produce greater improvement.

Cod liver oil nano-structured lipid carriers (Cod-NLCs) as a promising platform for nose to brain delivery: Preparation, in vitro optimization, ex vivo cytotoxicity & in vivo biodistribution utilizing radioiodinated zopiclone

Nano-structured lipid carriers containing zopiclone were prepared as a targeted drug delivery system to convey zopiclone directly to brain via nasal route. Nano-structured lipid carriers were constructed adopting hot emulsification-ultrasonication method using palmitic acid in place of the solid lipid, cod liver oil as liquid lipid, and poloxamer 407 as a surfactant. A three-factor three-level central composite face-centered design was used to optimize the formulated nano-structured lipid carriers. The independent factors were lipid amount (X₁), surfactant amount (X₂), and sonication time (X₃). The examined responses were entrapment efficiency (EE,Y₁,%), particle size (PS,Y₂,nm), zeta potential(mV), polydispersity index(PDI,Y₃), in vitro release(Q8h,Y₄,%) and dissolution efficiency (DE,Y₅,%). The optimum formula showed high entrapment efficiency of 94.31% ± 2.44, in vitro drug release of 83.89% ± 1.77 with dissolution efficiency equals 88.63% ± 2.01, small particle size of 71.27 nm ± 13.57 and low polydispersity index 0.097 ± 0.15. In vivo biodistribution in mice was evaluated by a radiobiological technique using radioiodinated zopiclone([¹³¹I]iodo-ZP). Results revealed the superiority of the intranasal route to deliver zopiclone directly to brain faster and higher brain uptake (6.9 ± 1.02%ID/g at 5 min post-administration). The current study confirmed that intranasal administration of nano-structured lipid carriers had great potential as an effective tool for targeted brain zopiclone delivery for insomnia treatment.

The role of cytochromes P450 in metabolism of selected antidepressants and anxiolytics under psychological stress

In today's modern society, it seems to be more and more challenging to cope with life stresses. The effect of psychological stress on emotional and physical health can be devastating, and increased stress is associated with increased rates of heart attack, hypertension, obesity, addiction, anxiety and depression. This review focuses on the possibility of an influence of psychological stress on the metabolism of selected antidepressants (TCAs, SSRIs, SNRIs, SARIs, NDRIs a MMAs) and anxiolytics (benzodiazepines and azapirone), as patients treated with antidepressants and/or anxiolytics can still suffer from psychological stress. Emphasis is placed on the drug metabolism mediated by the enzymes of Phase I, typically cytochromes P450 (CYPs), which are the major enzymes involved in drug metabolism, as the majority of psychoactive substances are metabolized by numerous CYPs (such as CYP1A2, CYP2B6, CYP2C19, CYP2C9, CYP2A6, CYP2D6, CYP3A4). As the data on the effect of stress on human enzymes are extremely rare, modulation of the efficacy and even regulation of the biotransformation pathways of drugs by psychological stress can be expected to play a significant role, as there is increasing evidence that stress can alter drug metabolism, hence there is a risk of less effective drug metabolism and increased side effects.

Multicentre analysis of practice patterns regarding benzodiazepine use in cardiac surgery

BACKGROUND

There is controversy regarding optimal use of benzodiazepines during cardiac surgery, and it is unknown whether and to what extent there is variation in practice. We sought to describe benzodiazepine use and sources of variation during cardiac surgeries across patients, clinicians, and institutions.

METHODS

We conducted an analysis of adult cardiac surgeries across a multicentre consortium of USA academic and private hospitals from 2014 to 2019. The primary outcome was administration of a benzodiazepine from 2 h before anaesthesia start until anaesthesia end. Institutional-, clinician-, and patient-level variables were analysed via multilevel mixed-effects models.

RESULTS

Of 65 508 patients cared for by 825 anaesthesiology attending clinicians (consultants) at 33 institutions, 58 004 patients (88.5%) received benzodiazepines with a median midazolam-equivalent dose of 4.0 mg (inter-quartile range [IQR], 2.0-6.0 mg). Variation in benzodiazepine dosage administration was 54.7% attributable to institution, 14.7% to primary attending anaesthesiology clinician, and 30.5% to patient factors. The adjusted median odds ratio for two similar patients receiving a benzodiazepine was 2.68 between two randomly selected clinicians and 4.19 between two randomly selected institutions. Factors strongly associated (adjusted odds ratio, <0.75, or >1.25) with significantly decreased likelihoods of benzodiazepine administration included older age (>80 vs ≤50 yr; adjusted odds ratio=0.04; 95% CI, 0.04-0.05), university affiliation (0.08, 0.02-0.35), recent year of surgery (0.42, 0.37-0.49), and low clinician case volume (0.44, 0.25-0.75). Factors strongly associated with significantly increased likelihoods of benzodiazepine administration included cardiopulmonary bypass (2.26, 1.99-2.55), and drug use history (1.29, 1.02-1.65).

CONCLUSIONS

Two-thirds of the variation in benzodiazepine administration during cardiac surgery are associated with institutions and attending anaesthesiology clinicians (consultants). These data, showing wide variations in administration, suggest that rigorous research is needed to guide evidence-based and patient-centred benzodiazepine administration.

Determination of zolpidem phenyl-4-carboxylic acid and zolpidem 6-carboxylic acid in hair using gas chromatography-electron ionization-tandem mass spectrometry

A gas chromatography-electron ionization-tandem mass spectrometric (GC-EI-MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC-EI-MS/MS. The linear ranges were 8-100 pg/mg for ZPCA and 16-200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra- and inter-day precisions were within 16.9 and 11.7%, while intra- and inter-day accuracies were -7.0-8.7 and -2.8-7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9-35.9 pg/mg and ZCA 16.6-21.8 pg/mg. The method proved to be suitable for picogram-level determination of ZPCA and ZCA in human hair.

The core pattern of Chinese herbal formulae and drug-herb concurrent usage in patients with dementia

More than 40% dementia patients received traditional Chinese Medicine treatment. However, the prescription pattern of Chinese herbal formulae (CHF) for treating neurocognitive or behavioral disorders in patients with dementia has not been elucidated. This large-scale survey aimed is to evaluate core patterns of CHF and drug-herb concurrent use in patients with dementia.We analyzed patients with a diagnosis of dementia from one million cohorts of the Longitudinal Health Insurance Database in the National Health Insurance Research Database, between 1997 and 2008. Of 18,141 newly diagnosed dementia patients, 3471 patients received CHF for mental and nervous system diseases. There were 13,254 outpatient visits, with 60,968 formulae prescriptions. We calculate the frequency and proportion of combined use, identify drug-herb concurrent usage, and determine core prescription patterns. Also, we drew network graphs of co-prescription pairs which occurred more than 200 times.Chinese medicine prescription patterns changed as dementia progressed.During the first 3 years after the diagnosis of dementia, Jia-Wei-Xiao-Yao-San, Gan-Mai-Da-Zao-Tang, and Ban-Xia-Bai-Zhu-Tian-Ma-Tang were the core CHF prescribed for mental and nervous system disorders. However, during the later stages of dementia, Suan-Zao-Ren-Tang, Gui-Pi-Tang, Jia-Wei-Xiao-Yao-San, and Wen-Dan-Tang were the core CHF prescribed. Benzodiazepines were the most common sedative drugs combined with traditional Chinese formulae.The results of this study suggest that TCM prescription were different in various stages of dementia, and indicated the frequently combined use of the TCM formulae and Benzodiazepines in dementia care.

Psychotropic drug therapy in patients in the intensive care unit - usage, adverse effects, and drug interactions: a review

Managing psychological problems in patients admitted to intensive care unit (ICU) is a big challenge, requiring pharmacological interventions. On the other hand, these patients are more prone to side effects and drug interactions associated with psychotropic drugs use. Benzodiazepines (BZDs), antidepressants, and antipsychotics are commonly used in critically ill patients. Therefore, their therapeutic effects and adverse events are discussed in this study. Different studies have shown that non-BZD drugs are preferred to BZDs for agitation and pain management, but antipsychotic agents are not recommended. Also, it is better not to start antidepressants until the patient has fully recovered. However, further investigations are required for the use of psychotropic drugs in ICUs.

Metabolic profile of oxazepam and related benzodiazepines: clinical and forensic aspects

Anxiolytic drugs, namely benzodiazepines, are the most commonly used psychoactive substances since anxiety disorders are prevalent mental disorders particularly in the Western world. Oxazepam is a short-acting benzodiazepine and one of the most frequently prescribed anxiolytic drugs. It is also the active metabolite of a wide range of other benzodiazepines, such as diazepam, ketazolam, temazepam, chlordiazepoxide, demoxazepam, halazepam, medazepam, prazepam, pinazepam, and chlorazepate. Therefore, relevant clinical and forensic outocomes may arise, namely those related to interference in driving performance. It is clinically available as a racemic formulation, with S-enantiomer being more active than R-enantiomer. In humans, it is mainly polimorphically metabolized by glucuronide conjugation at the 3-carbon hydroxyl group, yielding stable diastereomeric glucuronides (R- and S-oxazepam glucuronide). Relevant metabolic and stereoselective interspecies differences have been reported. In this work, the pharmacokinetics of oxazepam with particular focus on metabolic pathways is fully reviewed. Moreover, the metabolic profile of other prescribed benzodiazepines that produce oxazepam as a metabolite is also discussed. It is aimed that knowing the metabolism of oxazepam and related benzodiazepines may lead to the development of new analytical strategies for its early detection and help in further toxicological and clinical interpretations.

Prevalence and clinical correlates of flunitrazepam-related complex sleep behaviors

AIM

Complex sleep behaviors (CSB) are often associated with the use of hypnotic drugs. This study investigated the prevalence and correlates of CSB among psychiatric patients who were given flunitrazepam.

METHODS

From June 2011 to May 2012, a total of 268 psychiatric outpatients who had received flunitrazepam for at least 3 months were enrolled. Data on occurrence of CSB, demographic characteristics, flunitrazepam dosage and duration of use, psychiatric diagnoses, physical illnesses, and alcohol use were collected. Logistic regression analysis was used to examine the clinical correlates of CSB.

RESULTS

Sixty-six participants (24.6%) reported experiencing CSB. Logistic regression analysis showed that a high dosage (>2 mg/day) of flunitrazepam (odds ratio [OR] = 1.941, 95% confidence interval [CI] = 1.090-3.455, P = 0.024) and alcohol use (OR = 1.948, 95%CI = 1.023-3.709, P = 0.042) were significantly associated with the occurrence of CSB. Sex, age, duration of flunitrazepam use, psychiatric diagnoses, and physical illnesses were not significantly associated with the occurrence of CSB.

CONCLUSION

CSB among flunitrazepam users should be monitored routinely, especially among those receiving a high dosage who also consume alcohol.

CYP2C9 Genotypes Modify Benzodiazepine-Related Fall Risk: Original Results From Three Studies With Meta-Analysis

OBJECTIVE

To investigate whether the CYP2C9*2 and *3 variants modify benzodiazepine-related fall risk.

DESIGN

Three prospective studies; the Rotterdam Study, B-PROOF, and LASA.

SETTING

Community-dwelling individuals living in or near five Dutch cities.

PARTICIPANTS

There were 11,485 participants aged ≥55 years.

MEASUREMENTS

Fall incidents were recorded prospectively. Benzodiazepine use was determined using pharmacy dispensing records or interviews. Cox proportional hazard models adjusted for age and sex were applied to determine the association between benzodiazepine use and fall risk stratified for CYP2C9 genotype and comparing benzodiazepine users to nonusers. The results of the three studies were combined applying meta-analysis. Within benzodiazepine users, the association between genotypes and fall risk was also assessed.

RESULTS

Three thousand seven hundred five participants (32%) encountered a fall during 91,996 follow-up years, and 4% to 15% (depending on the study population) used benzodiazepines. CYP2C9 variants had frequencies of 13% for the *2 allele and 6% for the *3 allele. Compared to nonusers, current benzodiazepine use was associated with an 18% to 36% increased fall risk across studies with a combined hazard ratio (HR) = 1.26 (95% confidence interval [CI], 1.13; 1.40). CYP2C9*2 or *3 allele variants modified benzodiazepine-related fall risk. Compared to nonusers, those carrying a CYP2C9*2 or *3 allele and using benzodiazepines had a 45% increased fall risk (HR, 1.45 95% CI, 1.21; 1.73), whereas CYP2C9*1 homozygotes using benzodiazepines had no increased fall risk (HR, 1.14; 95% CI, 0.90; 1.45). Within benzodiazepine users, having a CYP2C9*2 or *3 allele was associated with an increased fall risk (HR, 1.35; 95% CI, 1.06; 1.72). Additionally, we observed an allele dose effect; heterozygous allele carriers had a fall risk of (HR = 1.30; 95% CI, 1.05; 1.61), and homozygous allele carriers of (HR = 1.91 95% CI, 1.23; 2.96).

CONCLUSIONS

CYP2C9*2 and *3 allele variants modify benzodiazepine-related fall risk. Those using benzodiazepines and having reduced CYP2C9 enzyme activity based on their genotype are at increased fall risk. In clinical practice, genotyping might be considered for elderly patients with an indication for benzodiazepine use. However, because the exact role of CYP2C9 in benzodiazepine metabolism is still unclear, additional research is warranted.

Increasing Benzodiazepine Prescriptions and Overdose Mortality in the United States, 1996-2013

OBJECTIVES

To describe trends in benzodiazepine prescriptions and overdose mortality involving benzodiazepines among US adults.

METHODS

We examined data from the Medical Expenditure Panel Survey and multiple-cause-of-death data from the Centers for Disease Control and Prevention.

RESULTS

Between 1996 and 2013, the percentage of adults filling a benzodiazepine prescription increased from 4.1% (95% confidence interval [CI] = 3.8%, 4.5%) to 5.6% (95% CI = 5.2%, 6.1%), with an annual percent change of 2.5% (95% CI = 2.1%, 3.0%). The quantity of benzodiazepines filled increased from 1.1 (95% CI = 0.9, 1.2) to 3.6 (95% CI = 3.0, 4.2) kilogram lorazepam equivalents per 100 000 adults (annual percent change = 9.0%; 95% CI = 7.6%, 10.3%). The overdose death rate increased from 0.58 (95% CI = 0.55, 0.62) to 3.07 (95% CI = 2.99, 3.14) per 100 000 adults, with a plateau seen after 2010.

CONCLUSIONS

Benzodiazepine prescriptions and overdose mortality have increased considerably. Fatal overdoses involving benzodiazepines have plateaued overall; however, no evidence of decreases was found in any group. Interventions to reduce the use of benzodiazepines or improve their safety are needed.

Simultaneous analysis of zolpidem and its metabolite in whole blood and oral fluid samples by SPE-LC/MS for clinical and forensic purposes

PURPOSE

The new analytical method of qualitative and quantitative determination of zolpidem and qualitative analysis of its main metabolite in blood and oral fluid samples was developed.

MATERIALS AND METHODS

Sample preparation was carried out using a polymeric ion-exchange sorbent in solid phase extraction (SPE). Analysis was realized using liquid chromatography with mass spectrometry detection (LC/MS). The method was validated in terms of few parameters. LOD, LOQ, linearity, precision, selectivity, ion suppression and stability were estimated.

RESULTS

Obtained method showed good linearity with determination coefficient (R(2)) of 0.9989 and 0.9998 for blood and oral fluid samples, respectively. LOD and LOQ of zolpidem were 0.2ng/mL and 1.0ng/mL, respectively, for both blood and oral fluid samples. SPE method recovery varies from 79.9±12.6 to 104.1±1.77 for blood sample and 80.2±0.48 to 103.8±1.51 for oral fluid sample. Samples collected from patients taking zolpidem with a prescription were analyzed. Detection of zolpidem was possible after 15h from ingestion of 10mg zolpidem tartrate in both types of samples.

CONCLUSION

The developed method allows quantitation of zolpidem in therapeutic and subtherapeutic range as well as qualitative analysis of its main metabolite in blood and oral fluid samples. This method meets criteria required for bioanalytical applications and can be used for clinical and forensic purposes.

Successful flumazenil reversal of paradoxical reaction to midazolam in a child

BACKGROUND

Greater attention to and management of anxiety and pain in pediatric patients signifies a healthy evolution in the care of children in emergency departments (EDs). Interventions to address such distress may involve unanticipated adverse effects. Midazolam, a benzodiazepine commonly administered to children for anxiolysis, may precipitate paradoxical agitation and delirium, a rare but alarming effect that warrants prompt identification and treatment.

CASE REPORT

The case presented is that of a 4-year-old girl who received oral midazolam and developed a paradoxical reaction, which was reversed successfully with flumazenil. This is the first such case report in an ED involving a child. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians must stay abreast of the adverse and unintended effects of the treatments provided. The literature on benzodiazepine-induced paradoxical reactions is reviewed, and flumazenil as well as other treatment options and anxiolytic alternatives are presented.

Does midazolam enhance pain control in prehospital management of traumatic severe pain?

PURPOSE

Midazolam comedication with morphine is a routine practice in pre and postoperative patients but has not been evaluated in prehospital setting. We aimed to evaluate the comedication effect of midazolam in the prehospital traumatic adults.

METHODS

A prehospital prospective randomized double-blind placebo-controlled trial of intravenous morphine 0.10 mg/kg and midazolam 0.04 mg/kg vs morphine 0.10 mg/kg and placebo. Pain assessment was done using a validated numeric rating scale (NRS). The primary end point was to achieve an efficient analgesic effect (NRS≤3) 20 minutes after the baseline. The secondary end points were treatment safety, total morphine dose required until obtaining NRS≤3, and efficient analgesic effect 30 minutes after the baseline.

FINDINGS

Ninety-one patients were randomized into midazolam (n=41) and placebo (n=50) groups. No significant difference in proportion of patients with a pain score≤3 was observed between midazolam (43.6%) and placebo (45.7%) after 20 minutes (P=.849). Secondary end points were similar in regard with proportion of patients with a pain score≤3 at T30, the side effects and adverse events except for drowsiness in midazolam vs placebo, 43.6% vs 6.5% (P<.001). No significant difference in total morphine dose was observed, that is, midazolam (14.09 mg±6.64) vs placebo (15.53 mg±6.27) (P=.315).

CONCLUSIONS

According to our study, midazolam does not enhance pain control as an adjunctive to morphine regimen in the management of trauma-induced pain in prehospital setting. However, such midazolam use seems to be associated with an increase in drowsiness.

Clinically significant psychotropic drug-drug interactions in the primary care setting

In recent years, the growing numbers of patients seeking care for a wide range of psychiatric illnesses in the primary care setting has resulted in an increase in the number of psychotropic medications prescribed. Along with the increased utilization of psychotropic medications, considerable variability is noted in the prescribing patterns of primary care providers and psychiatrists. Because psychiatric patients also suffer from a number of additional medical comorbidities, the increased utilization of psychotropic medications presents an elevated risk of clinically significant drug interactions in these patients. While life-threatening drug interactions are rare, clinically significant drug interactions impacting drug response or appearance of serious adverse drug reactions have been documented and can impact long-term outcomes. Additionally, the impact of genetic variability on the psychotropic drug's pharmacodynamics and/or pharmacokinetics may further complicate drug therapy. Increased awareness of clinically relevant psychotropic drug interactions can aid clinicians to achieve optimal therapeutic outcomes in patients in the primary care setting.

Pharmacokinetic drug interactions and adverse consequences between psychotropic medications and pharmacotherapy for the treatment of opioid dependence

BACKGROUND

Psychiatric comorbidities among opioid-dependent patients are common. Many medications used to treat both conditions are metabolized through complimentary cytochrome P450 isoenzymes. When medication-assisted treatment for opioid dependence is concurrently used with psychotropic medications, problematic pharmacokinetic drug interactions may occur.

METHODS

We reviewed relevant English language articles identified through the MedLine, Scopus, and Embase databases from 1950 to December 2009 using the specific generic names of medications and keywords such as pharmacokinetics and drug interactions with buprenorphine, methadone, and naltrexone. Selected references from these articles were reviewed. Additionally, a review was conducted of abstracts and conference proceedings from national and international meetings from 1990 to 2009. A total of 60 studies were identified and reviewed.

RESULTS

Clinical case series and carefully controlled pharmacokinetic interaction studies have been conducted between methadone, buprenorphine, or naltrexone and some psychoactive medications. Important pharmacokinetic drug interactions have been demonstrated within each class of medications affecting either methadone and buprenorphine or psychoactive drugs. Few studies, however, have been conducted with naltrexone.

CONCLUSIONS

Several interactions between methadone, buprenorphine, or naltrexone and psychoactive medications are described and may have important clinical consequences. To optimize care, clinicians must be alerted to these interactions.

Zolpidem, a clinical hypnotic that affects electronic transfer, alters synaptic activity through potential GABA receptors in the nervous system without significant free radical generation

Zolpidem (trade name Ambien) has attracted much interest as a sleep-inducing agent and also in research. Attention has been centered mainly on receptor binding and electrochemistry in the central nervous system which are briefly addressed herein. A novel integrated approach to mode of action is presented. The pathways to be discussed involve basicity, reduction potential, electrostatics, cell signaling, GABA receptor binding, electron transfer (ET), pharmacodynamics, structure activity relationships (SAR) and side effects. The highly conjugated pyridinium salt formed by protonation of the amidine moiety is proposed to be the active form acting as an ET agent. Extrapolation of reduction potentials for related compounds supports the premise that zolpidem may act as an ET species in vivo. From recent literature reports, electrostatics is believed to play a significant role in drug action.

The pyridinium cation displays molecular electrostatic potential which may well play a role energetically or as a bridging mechanism. An SAR analysis points to analogy with other physiologically active xenobiotics, namely benzodiazepines and paraquat in the conjugated iminium category. Inactivity of metabolites indicates that the parent is the active form of zolpidem. Absence of reactive oxygen species and oxidative stress is in line with minor side effects. In contrast, generally, the prior literature contains essentially no discussion of these fundamental biochemical relationships. Pharmacodynamics may play an important role. Concerning behavior at the blood-brain barrier, useful insight can be gained from investigations of the related cationic anesthetics that are structurally related to acetyl choline. Evidently, the neutral form of the drug penetrates the neuronal membrane, with the salt form operating at the receptor. The pathways of zolpidem have several clinical implications since the agent affects sedation, electroencephalographic activity, oxidative metabolites and receptors in the central nervous system. The drug acts at the GABA(A) receptor benzodiazepine site, displaying high and intermediate affinities to various receptor regions. Structural features for tight binding were determined. The sedative and anticonvulsant activities are due to its action on the alpha-1-GABA(A) receptors. One of the common adverse responses to zolpidem is hallucinations. Proposed mechanisms comprise changes in the GABA(A) receptor, pharmacodynamic interactions involving serotonin and neuronal-weak photon emission processes entailing redox phenomena. Reports cite cases of abuse with cravings based on anxiolytic and stimulating actions. It is important to recognize that insight concerning processes at the fundamental, molecular level can translate into beneficial results involving both positive and adverse side effects. In order for this to occur, interdisciplinary interaction is necessary. Suggestions are made for future research aimed at testing the various hypotheses.

British Association for Psychopharmacology consensus statement on evidence-based treatment of insomnia, parasomnias and circadian rhythm disorders

Sleep disorders are common in the general population and even more so in clinical practice, yet are relatively poorly understood by doctors and other health care practitioners. These British Association for Psychopharmacology guidelines are designed to address this problem by providing an accessible up-to-date and evidence-based outline of the major issues, especially those relating to reliable diagnosis and appropriate treatment. A consensus meeting was held in London in May 2009. Those invited to attend included BAP members, representative clinicians with a strong interest in sleep disorders and recognized experts and advocates in the field, including a representative from mainland Europe and the USA. Presenters were asked to provide a review of the literature and identification of the standard of evidence in their area, with an emphasis on meta-analyses, systematic reviews and randomized controlled trials where available, plus updates on current clinical practice. Each presentation was followed by discussion, aimed to reach consensus where the evidence and/or clinical experience was considered adequate or otherwise to flag the area as a direction for future research. A draft of the proceedings was then circulated to all participants for comment. Key subsequent publications were added by the writer and speakers at draft stage. All comments were incorporated as far as possible in the final document, which represents the views of all participants although the authors take final responsibility for the document.

Psychiatric pharmaceuticals in the environment

Psychiatric pharmaceuticals, such as anxiolytics, sedatives, hypnotics, and antidepressants, are among the most prescribed active substances throughout the world. The occurrence of these widely used compounds in environmental matrices (wastewaters, surface, ground and drinking waters, soils, sediments, bio-solids and tissue), as well as the first studies indicating their high persistence and toxicity to non-target organisms, justify the growing concern about these emerging environmental pollutants. Despite this increasing interest, there is a considerable lack of knowledge about the environmental fate of a large number of psychiatric pharmaceuticals and further research about this topic is needed. This paper aims to review the literature data related to the occurrence, persistence, environmental fate and toxicity for non-target organisms of this group of pharmaceuticals. The analytical methods developed for the determination of psychiatric medicines in environmental matrices are also highlighted.

Psychotropic drugs and renal failure: translating the evidence for clinical practice

INTRODUCTION

The kidney is a primary route of drug elimination; abnormal kidney function is predicted to alter the pharmacokinetics of agents metabolized and/or excreted predominantly through this route. The high prevalence of mental disorders associated with psychotropic drug use in individuals with deteriorating renal function suggests there is a need to investigate the effects of renal failure on psychotropic pharmacokinetics. The aim of this review is to provide a clinically accessible overview of the effect of chronic renal failure on the pharmacokinetics for each of the major classes of prescribed psychotropic agents.

METHODS

All English language articles published between 1977 and 2008 were searched through PubMed, using the following keywords: "renal," "kidney," "pharmacokinetics," "renal impairment," "renal insufficiency," and "renal failure." Each of these search words was cross-referenced with the non-proprietary name of each psychotropic agent. The manufacturer's product insert was also reviewed for some agents for updated dosing. Owing to the lack of adequately powered studies, an inclusive manner was used.

RESULTS

Chronic renal failure variably affects the pharmacokinetic parameters of psychotropic drugs. A review of each psychotropic drug is provided, with an emphasis on the individual pharmacokinetic parameters and recommended dosing.

CONCLUSIONS

The adjudication of safe and effective doses for any psychotropic agent needs to be individualized. Tactics including dosage adjustment, slow titration, and careful monitoring for serious adverse events should be incorporated into practice.

[Determination of diazepam and its metabolites in serum by the use of liquid chromatography-mass spectrometry method]

BACKGROUND/AIM

Diazepam is a benzodiazepine anxyolitic. Metabolism of diazepam takes place in liver which generates pharmacologically active metabolites N-desmethyldiazepam, temazepam and oxazepam. The aim of this study was to develop and validate the method of liquid chromatographymass spectrometry (LC-MS) for separation and determination of diazepam and its active metabolites in the serum of rats samples after i.p. application of diazepam in a dose of 10 mg/kg.

METHODS

The serum samples taken from Wistar rats, were used in LC-MS analysis after the application of 10 mg/kg of diazepam i.p.

RESULTS

After alkaline extraction from the serum samples with diethylether and separation on a C18 reversed-phase column by using mobile phase methanolglacial acetic acid-water (50:1:49 v/v), diazepam and its metabolites were quantified. Determination was performed in a selective ion monitoring (SIM) mode, thereby the other exogenous and endogenous compounds did not interfere with this assay. Diazepam, N-desmethyldiazepam, oxazepam and temazepam were eluted in 14 minutes. The standard curve was linear in the range from 10-2 000 ng/ml. The limits of detection for diazepam, N-desmethyldiazepam, oxazepam and temazepam were 4.37, 3.13, 4.38 and 7.31 ng/ml, respectively. The limits of quantitation for diazepam, N-desmethyldiazepam, oxazepam and temazepam were 14.58, 10.41, 14.59 and 24.36 ng/ml, respectively.

CONCLUSION

The described LC-MS is a simple, sensitive, specific and accurate method and could be used for routine identification and quantification of small concentrations of diazepam and its metabolites in biological fluids.

Pharmacologic management of insomnia: past, present, and future

Views on the etiology and morbidities associated with insomnia are evolving and affect clinicians' approach to the pharmacologic management of insomnia. Currently, benzodiazepine receptor agonists (BzRAs) and a single melatonin receptor agonist are recognized as safe and efficacious hypnotics. Variability in BzRAs, pharmacokinetics, and manipulation of dose provide clinicians with options that meet the needs of most patients. Other drugs (eg, sedating antidepressants) also are used commonly in clinical practice to treat insomnia, but evidence is lacking to support this most cases. Improvement in managing insomnia will result from systematic research with these drugs, with drugs in development, and with novel uses, such as co-therapy.

Cytochrome P450 (CYP) inhibition screening: Comparison of three tests

There are several different experimental systems for screening of in vitro inhibitory potency of drugs under development. In this study we compared three different types of cytochrome P450 (CYP) inhibition tests: the traditional single substrate assays, the fluorescent probe method with recombinant human CYPs, and a novel n-in-one technique. All major hepatic drug-metabolizing CYPs were included (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4). Six compounds (sotalol, propranolol, citalopram, fluoxetine, oxazepam and diazepam) were selected for detailed comparisons. The IC50 values of each of these compounds were measured using the three assay types. The inhibitory potencies of these model drugs were generally within the same order of magnitude and followed similar inhibition profiles in all the assay types. Clinically observed inhibitory interactions, or lack thereof, were predictable with all three assays. Comparison of potencies of 'diagnostic' inhibitors revealed also some notable differences between the assays, especially regarding CYP2E1. The potency of inhibitors towards CYP3A4 was dependent on the substrate and reaction measured. Generally all three assays gave reasonably comparable results, although some unexplained differences were also noted.

Drug interactions during therapy with three major groups of antimicrobial agents

This review focuses on drug-drug interactions with three major groups of antimicrobial agents: macrolides (including azalides and ketolides), quinolones, which are widely used for the treatment of bacterial infections, and azoles, which are used for antifungal therapy. Macrolides and the ketolide telithromycin are potent inhibitors of CYP3A4 and thus interfere with the pharmacokinetics of many other drugs that are metabolised by this enzyme. In contrast, although closely related, azithromycin is not a cytochrome inhibitor. All quinolones form complexes with di- and trivalent cations and, therefore, the absorption of quinolones can be dramatically reduced when given concomitantly with mineral antacids, zinc or iron preparations. Ciprofloxacin exhibits an inhibitory potential for the cytochrome isoenzyme 1A2, resulting in an inhibition of theophylline metabolism. Other quinolones, such as levofloxacin or moxifloxacin, do not interfere with theophylline metabolism. The systemic azoles, such as ketoconazole, itraconazole, fluconazole and voriconazole, are inhibitors of CYP isoenzymes, such as CYP3A4, CYP2C9 and CYP2C19, to varying degrees. In addition, some are substrates of the MDR-1 gene product, P-glycoprotein. These features are the basis for most of the interactions occurring during azole therapy (e.g., in severely ill patients in the hospital who are treated with multiple drugs).

Drug bioactivation, covalent binding to target proteins and toxicity relevance

A number of therapeutic drugs with different structures and mechanisms of action have been reported to undergo metabolic activation by Phase I or Phase II drug-metabolizing enzymes. The bioactivation gives rise to reactive metabolites/intermediates, which readily confer covalent binding to various target proteins by nucleophilic substitution and/or Schiff's base mechanism. These drugs include analgesics (e.g., acetaminophen), antibacterial agents (e.g., sulfonamides and macrolide antibiotics), anticancer drugs (e.g., irinotecan), antiepileptic drugs (e.g., carbamazepine), anti-HIV agents (e.g., ritonavir), antipsychotics (e.g., clozapine), cardiovascular drugs (e.g., procainamide and hydralazine), immunosupressants (e.g., cyclosporine A), inhalational anesthetics (e.g., halothane), nonsteroidal anti-inflammatory drugs (NSAIDSs) (e.g., diclofenac), and steroids and their receptor modulators (e.g., estrogens and tamoxifen). Some herbal and dietary constituents are also bioactivated to reactive metabolites capable of binding covalently and inactivating cytochrome P450s (CYPs). A number of important target proteins of drugs have been identified by mass spectrometric techniques and proteomic approaches. The covalent binding and formation of drug-protein adducts are generally considered to be related to drug toxicity, and selective protein covalent binding by drug metabolites may lead to selective organ toxicity. However, the mechanisms involved in the protein adduct-induced toxicity are largely undefined, although it has been suggested that drug-protein adducts may cause toxicity either through impairing physiological functions of the modified proteins or through immune-mediated mechanisms. In addition, mechanism-based inhibition of CYPs may result in toxic drug-drug interactions. The clinical consequences of drug bioactivation and covalent binding to proteins are unpredictable, depending on many factors that are associated with the administered drugs and patients. Further studies using proteomic and genomic approaches with high throughput capacity are needed to identify the protein targets of reactive drug metabolites, and to elucidate the structure-activity relationships of drug's covalent binding to proteins and their clinical outcomes.

Insomnia in General Practice

Insomnia is an extremely common condition with major social and economic consequences worldwide. Two large epidemiological studies (Morfeo 1 and Morfeo 2) recently performed in Italy provided much-needed novel data on the impact of insomnia in patients whose primary healthcare is provided by general practitioners (GPs). These studies found that insomnia is managed relatively well by GPs in Italy, although diagnosis and treatment can be compromised because of the lack of standardised criteria. Although a number of consensus reports on insomnia have been published, these are mainly highly specific documents that are difficult to implement in general practice. To address this, a consensus group involving 695 GPs and over 60 specialists from the Italian Association of Sleep Medicine was established. The major objectives of the consensus study were to establish basic knowledge for the diagnosis and treatment of insomnia, and to produce guidelines for the management of insomnia by GPs. This is the first time that GPs have been directly involved in producing insomnia guidelines of this type, and this approach reflects their pivotal role in the diagnosis and management of this condition. Participants were carefully selected to ensure adequate representation of sleep specialists and GPs, with the group being headed by a steering committee and an advisory board. Guideline statements were selected following careful literature review and were voted on using formalised consensus procedures. This review describes current views on the diagnosis and management of insomnia from the perspective of the GP. In addition, the results of the consensus study are presented. They include recognition of the following principles: (i) insomnia is a genuine pathology that must be appropriately diagnosed and treated; (ii) when concomitant pathologies are present, additional significance should be given to treatment of insomnia since it can influence prognosis of coexistent disorders; (iii) appropriate treatment should consider the cause of insomnia as well as the characteristics of available pharmacological agents; (iv) with regard to hypnotic drugs, preference should be given to medications with a short half-life in order to limit residual effects; (v) non-benzodiazepine hypnotics are preferred to classic benzodiazepines as they have higher selectivity and present a lower risk of undesirable effects; (vi) tablets are preferable to liquid preparations as they are less likely to lead to dependence and to overdosing by the patient; and (vi) once treatment has been initiated, insomnia patients should be carefully followed up. These statements provide much needed criteria for better management of insomnia by GPs in Italy.

Treatment of Anxiety and Depression in Transplant Patients

Depressive and anxiety disorders appear during the transplant process due to psychological stressors, medications and physiological disturbances. Treatment is necessary to prevent impact on patient compliance, morbidity and mortality. Psychotropic medications provide an effective option, although most are only available as oral formulations. Because of this, they are more susceptible to alterations in pharmacokinetic behaviour arising from organ dysfunction in the pretransplant period. Kinetics are also an issue when considering potential drug-drug interactions before and after transplantation. Prior to transplant, organ dysfunction can change the pharmacokinetic behaviour of some psychotropic agents, requiring adjustment of dosage and schedules. Thoracic or abdominal organ failure may reduce drug absorption through disturbances in intestinal motility, perfusion and function. Cirrhotic patients experience increased drug bioavailability due to portosystemic shunting, and thus dosage is adjusted downward. In contrast, dosage needs to be raised when peripheral oedema expands the drug distribution volume for hydrophilic and protein-bound agents. Drug clearance for most psychotropic medications is dependent upon hepatic metabolism, which is often disrupted by endstage organ disease. Selection of drugs or their dosage may need to be adjusted to lower the risk of drug accumulation. Further adjustments in dosage may be called for when renal failure accompanies thoracic or abdominal organ failure, resulting in further impairment of clearance. Studies regarding the treatment of anxiety and depressive disorders in the medically ill are limited in number, but recommendations are possible by review of clinical and pharmacokinetic data. Selective serotonin reuptake inhibitors are well tolerated and efficacious for depression, panic disorder and post-traumatic stress disorder. Adjustments in dosage are required when renal or hepatic impairment is present. Among them, citalopram and escitalopram appear to have the least risk of drug-drug interactions. Paroxetine has demonstrated evidence supporting its use with generalised anxiety disorder. Venlafaxine is an alternative option, beneficial in depression, post-traumatic stress and generalised anxiety disorders. Nefazodone may also be considered, but there is some risk of hepatotoxicity and interactions with immunosuppressant drugs. Mirtazapine still needs to be studied further in anxiety disorders, but can be helpful for depression accompanied by anorexia and insomnia. Bupropion is effective in the treatment of depression, but data are sparse about its use in anxiety disorders. Psychostimulants are a unique approach if rapid onset of antidepressant action is desired. Acute or short-term anxiolysis is obtained with benzodiazepines, and selection of particular agents entails consideration of distribution rate, half-life and metabolic route.

Clinically important drug interactions with zopiclone, zolpidem and zaleplon

Insomnia, an inability to initiate or maintain sleep, affects approximately one-third of the American population. Conventional benzodiazepines, such as triazolam and midazolam, were the treatment of choice for short-term insomnia for many years but are associated with adverse effects such as rebound insomnia, withdrawal and dependency. The newer hypnosedatives include zolpidem, zaleplon and zopiclone. These agents may be preferred over conventional benzodiazepines to treat short-term insomnia because they may be less likely to cause significant rebound insomnia or tolerance and are as efficacious as the conventional benzodiazepines. This review aims to summarise the published clinical drug interaction studies involving zolpidem, zaleplon and zopiclone. The pharmacokinetic and pharmacodynamic interactions that may be clinically important are highlighted. Clinical trials have studied potential interactions of zaleplon, zolpidem and zopiclone with the following types of drugs: cytochrome P450 (CYP) inducers (rifampicin), CYP inhibitors (azoles, ritonavir and erythromycin), histamine H(2) receptor antagonists (cimetidine and ranitidine), antidepressants, antipsychotics, antagonists of benzodiazepines and drugs causing sedation. Rifampicin significantly induced the metabolism of the newer hypnosedatives and decreased their sedative effects, indicating that a dose increase of these agents may be necessary when they are administered with rifampicin. Ketoconazole, erythromycin and cimetidine inhibited the metabolism of the newer hypnosedatives and enhanced their sedative effects, suggesting that a dose reduction may be required. Addition of ethanol to treatment with the newer hypnosedatives resulted in additive sedative effects without altering the pharmacokinetic parameters of the drugs. Compared with some of the conventional benzodiazepines, fewer clinically important interactions appear to have been reported in the literature with zaleplon, zolpidem and zopiclone. The fact that these drugs are newer to the market and have not been as extensively studied as the conventional benzodiazepines may be the reason for this. Another explanation may be a difference in CYP metabolism. While triazolam and midazolam are biotransformed almost entirely via CYP3A4, the newer hypnosedatives are biotransformed by several CYP isozymes in addition to CYP3A4, resulting in CYP3A4 inhibitors and inducers having a lesser effect on their biotransformation.

New drugs for insomnia: comparative tolerability of zopiclone, zolpidem and zaleplon

Insomnia affects 30-35% of people living in developed countries. The impact of insomnia on daytime functioning and its relationship with medical and psychiatric illnesses necessitate early treatment to prevent insomnia becoming persistent and to avoid the development of complications. However, pharmacological strategies must achieve a balance between sedative and adverse effects. In the last 30 years, benzodiazepines have been the preferred drugs for the treatment of insomnia. Benzodiazepines act nonselectively at two central receptor sites, named omega(1) and omega(2), which are located in different areas of the CNS. The sedative action of benzodiazepines is related to omega(1) receptors, whereas omega(2) receptors are responsible for their effects on memory and cognitive functioning. According to their pharmacokinetic profile, benzodiazepines can be classified into three groups: short half-life (<3 hours), medium half-life (8-24 hours) and long half-life (>24 hours). The newer non-benzodiazepine agents zopiclone, zolpidem and zaleplon have a hypnosedative action comparable with that of benzodiazepines, but they display specific pharmacokinetic and pharmacodynamic properties. These three 'Z' agents all share a short plasma half-life and limited duration of action. In addition, these agents are selective compounds that interact preferentially with omega(1) receptors (sedative effect), whereas benzodiazepines also interact with omega(2) receptors (adverse effects on cognitive performance and memory). Zaleplon is characterised by an ultrashort half-life (approximately 1 hour). Zolpidem and zopiclone have longer half-lives (approximately 2.4 and 5 hours, respectively). These properties, together with the low risk of residual effect, may explain the limited negative influences of these agents on daytime performance. Psychomotor tasks and memory capacities appear to be better preserved by non-benzodiazepine agents than by benzodiazepines. When present, cognitive deficits almost exclusively coincide with the peak plasma concentration. In particular, impairment can emerge in the first hours after drug administration, whereas psychomotor and memory tests carried out 7-8 hours later (i.e. in the morning) generally show no relevant alterations. As with benzodiazepines, the three 'Z' non-benzodiazepine agents should be used for a limited period, even in chronic relapsing conditions. Further evaluation is needed of the safety of hypnosedative medications in the long-term management of insomnia.

Abortion and psychiatric practice

The subject of abortion is fraught with politics, emotions, and misinformation. A widespread practice reaching far back in history, abortion is again in the news. Psychiatry sits at the intersection of the religious, ethical, psychological, sociological, medical, and legal facets of the abortion issue. Although the religions that forbid abortion are more prominent in the media, many religions have more liberal approaches. While the basic right to abortion has been upheld by the U.S. Supreme Court, several limitations have been permitted, including parental notification or consent (with the possibility of judicial bypass) for minors, waiting periods, and mandatory provision of certain, sometimes biased, information. Before the Roe v. Wade decision legalizing abortion in 1973, many women were maimed or killed by illegal abortions, and psychiatrists were sometimes asked to certify that abortions were justified on psychiatric grounds. Currently, there are active attempts to convince the public and women considering abortion that abortion frequently has negative psychiatric consequences. This assertion is not borne out by the literature: the vast majority of women tolerate abortion without psychiatric sequelae. The psychiatric outcome of abortion is best when patients are able to make autonomous, supported decisions. Psychiatrists need to know the medical and psychiatric facts about abortion. Psychiatrists can then help patients prevent unwanted pregnancies, make informed decisions consonant with their own values and circumstances when they become pregnant, and find appropriate social and medical resources whatever their decisions may be.