Therapeutic drug monitoring in Italian psychiatry

A Survey of Therapeutic Drug Monitoring Status in China

OBJECTIVE

To understand the status of therapeutic drug monitoring (TDM) in China Mainland, and thus lay down the foundation for further improvement in TDM.

METHODS

In the present study, a nationwide questionnaire survey was conducted, which was distributed and collected using a mobile-based application. Clinicians, pharmacists, and clinical laboratory physicians belonging to different levels of public hospitals were involved as subjects/objects. The contents of the survey included TDM implementation in their hospital and information regarding their opinions and suggestions on TDM work. Mann-Whitney test was used to compare the difference between top tertiary hospitals and non-top tertiary hospitals.

RESULTS

A total of 475 questionnaires were collected, 383 from top tertiary hospitals (3A hospitals) and 92 from non-top tertiary hospitals (other than 3A hospitals). A total of 240 clinicians, TDM pharmacists, and clinical laboratory physicians were involved, with an effective rate of 50.5%. Top tertiary hospitals were associated with certain advantages, such as the number of TDM testing facilities, annual sample size, number of monitoring varieties, and interpretation rate of monitoring reports, compared with non-top tertiary hospitals. In particular, β-lactamase inhibitor, olanzapine, carbamazepine, and glucocorticoids seemed to be the main projects that clinicians wanted to assess. The drugs for which TDM was commonly performed included vancomycin, valproic acid, carbamazepine, phenytoin sodium, and methotrexate. The most commonly used detection methods include high-performance liquid chromatography, immunization, 2D-LC, and LC-MS. The monitoring concentration range was found to be inconsistent for most of the drugs. Currently, no unified regulation exists for TDM charges in China, which is no more than ¥200 in general. Clinicians rely on pharmacists for professional guidance. Importantly, improvement in the interpretation of monitoring reports, proficiency testing, and cooperation with clinical departments may aid in improving the level of TDM service.

CONCLUSIONS

This survey objectively reflected the current status of TDM work in hospitals in China, and provided a strong reference base for devising strategies for improvement and effective execution of TDM work.

Current Status of Therapeutic Drug Monitoring in Mental Health Treatment: A Review

Therapeutic drug monitoring (TDM) receives growing interest in different psychiatric clinical settings (emergency, inpatient, and outpatient services). Despite its usefulness, TDM remains underemployed in mental health. This is partly due to the need for evidence about the relationship between drug serum concentration and efficacy and tolerability, both in the general population and even more in subpopulations with atypical pharmacokinetics. This work aims at reviewing the scientific literature published after 2017, when the most recent guidelines about the use of TDM in mental health were written. We found 164 pertinent records that we included in the review. Some promising studies highlighted the possibility of correlating early drug serum concentration and clinical efficacy and safety, especially for antipsychotics, potentially enabling clinicians to make decisions on early laboratory findings and not proceeding by trial and error. About populations with pharmacokinetic peculiarities, the latest studies confirmed very common alterations in drug blood levels in pregnant women, generally with a progressive decrease over pregnancy and a very relevant dose-adjusted concentration increase in the elderly. For adolescents also, several drugs result in having different dose-related concentration values compared to adults. These findings stress the recommendation to use TDM in these populations to ensure a safe and effective treatment. Moreover, the integration of TDM with pharmacogenetic analyses may allow clinicians to adopt precise treatments, addressing therapy on an individual pharmacometabolic basis. Mini-invasive TDM procedures that may be easily performed at home or in a point-of-care are very promising and may represent a turning point toward an extensive real-world TDM application. Although the highlighted recent evidence, research efforts have to be carried on: further studies, especially prospective and fixed-dose, are needed to replicate present findings and provide clearer knowledge on relationships between dose, serum concentration, and efficacy/safety.

Venlafaxine and O-desmethylvenlafaxine serum levels are positively associated with antidepressant response in elder depressed out-patients

BACKGROUND

Therapeutic Drug Monitoring (TDM) represents one of the most promising tools in clinical practice to optimise antidepressant treatment. Nevertheless, little is still known regarding the relationship between clinical efficacy and serum concentration of venlafaxine (VEN). The aim of our study was to investigate the association between serum concentration of venlafaxine + O-desmethylvenlafaxine (SCVO) and antidepressant response (AR).

METHODS

52 depressed outpatients treated with VEN were recruited and followed in a naturalistic setting for three months. Hamilton Depression Rating Scale-21 was administered at baseline, at month 1 and at month 3 to assess AR. SCVO was measured at steady state. Linear regression analysis and nonlinear least-squares regression were used to estimate association between SCVO and AR.

RESULTS

Our results showed an association between AR and SCVO that follows a bell-shaped quadratic function with a progressive increase of AR within the therapeutic reference range of SCVO (i.e. 100-400 ng/mL) and a subsequent decrease of AR at higher serum levels.

DISCUSSION

This study strongly suggests that TDM could represent a more appropriate tool than the oral dosage to optimise the treatment with VEN. Specifically, highest efficacy might be achieved by titrating patients at SCVO levels around 400 ng/mL.

Quantitative microsampling for bioanalytical applications related to the SARS-CoV-2 pandemic: Usefulness, benefits and pitfalls

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SARS-CoV-2 emergency sparks the need for diagnostic and therapeutic actions.

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Microsampling is emerging in as an attractive alternative to traditional sampling.

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Advantages and challenges of the main microsampling techniques are reported.

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Available microsampling applications of interest for SARS-CoV-2 are described.

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Most useful information for researchers and clinicians are gathered and provided.

The multiple pathological effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and its total novelty, mean that currently a lot of diagnostic and therapeutic tools, established and tentative alike, are needed to treat patients in a timely, effective way. In order to make these tools more reliable, faster and more feasible, biological fluid microsampling techniques could provide many advantages. In this review, the most important microsampling techniques are considered (dried matrix spots, volumetric absorptive microsampling, microfluidics and capillary microsampling, solid phase microextraction) and their respective advantages and disadvantages laid out. Moreover, currently available microsampling applications of interest for SARS-CoV-2 therapy are described, in order to make them as much widely known as possible, hopefully providing useful information to researchers and clinicians alike.

Prevalence of Therapeutic Drug Monitoring for Lithium and the Impact of Regulatory Warnings: Analysis Using Japanese Claims Database

Background:

Therapeutic drug monitoring (TDM) for lithium is recommended in guidelines; however, the prevalence of TDM for lithium is seldom reported. We have therefore investigated the prevalence of TDM for lithium and evaluated the impact of the regulatory warnings requiring routine TDM for lithium.

Methods:

Monthly claims data covering around 1.7 million persons aged 20–74 years old during the period January 1, 2005, and March 31, 2015, were evaluated. All patients who had at least one prescription for lithium were selected and included to calculate the annual prevalence of TDM for lithium. Also we assessed whether the 2 regulatory warnings requiring routine TDM for lithium and issued in April 2012 and September 2012 had an impact on TDM for lithium, using segmented regression analysis.

Results:

Between 2005 and 2014, 136,956 prescriptions of lithium were issued to 5823 patients, and the annual prevalence of TDM for lithium was 14.9% (95% confidence interval, 14.7%–15.1%). The analysis revealed that the mean prevalence increased abruptly by 6.9% (P = 0.001) after the regulatory warning in April 2012, whereas that the warning in September 2012 decreased by 1.2% (P = 0.47). There was no significant change in trends of period prevalence after the warning in April 2012 (April 2012–August 2012) compared with prevalence before the warning (April 2010–March 2012). Similarly, no significant change was observed in the trends before (April 2012–August 2012) and after (September 2012–March 2014) the subsequent warning in September 2012.

Conclusions:

Results showed that the prevalence of TDM for lithium was low, although TDM for lithium was strongly recommended by the guidelines. Regulatory warnings requiring compliance with the measurement of blood levels during treatment with lithium, issued twice during the five-month period, were associated with an increase in the prevalence of TDM for lithium. However, the impact of the second warning was not remarkable compared with the first warning.

Patterns of Prescription of Psychotropic Medications and Their Adherence among Patients with Schizophrenia in Two Psychiatric Hospitals in Accra, Ghana: A Cross-Sectional Survey

Background

Patients with schizophrenia are managed with antipsychotics and other psychotropic medications.

Objectives

This study aimed to assess the commonly prescribed psychotropic medications for patients with schizophrenia, explore the types of therapeutic monitoring that were performed, and find out whether the side effects experienced by the patients played any role in their adherence behaviour.

Methods

This hospital-based cross-sectional study enrolled 259 patients with schizophrenia from Accra Psychiatric Hospital and Pantang Psychiatric Hospital. Data were collected on mental status, side effects, types of therapeutic monitoring performed, and adherence behaviour.

Results

Olanzapine was the commonly prescribed psychotropic medication. Most of respondents (73.4%) experienced mild levels of side effects. The negative effects were predominantly genitourinary (26%) and gastrointestinal (17.2%). Blood pressure and heart rate measures were the main types of monitoring performed but no measurement of drug levels was reported. About 98.1% of the participants poorly adhered to their medications and the major reasons for poor adherence were economic challenges, forgetfulness, and the feeling of wellness.

Conclusion

Adherence to medication is a major health problem among patients with schizophrenia and there is a need to improve adherence and treatment outcomes.

Antipsychotic plasma levels in the assessment of poor treatment response in schizophrenia

OBJECTIVE

Treatment resistance is a challenge for the management of schizophrenia. It is not always clear whether inadequate response is secondary to medication ineffectiveness, as opposed to medication underexposure due to non-adherence or pharmacokinetic factors. We investigated the prevalence of subtherapeutic antipsychotic plasma levels in patients identified as treatment-resistant by their treating clinician.

METHOD

Between January 2012 and April 2017, antipsychotic plasma levels were measured in 99 individuals provisionally diagnosed with treatment-resistant schizophrenia by their treating clinicians, but not prescribed clozapine. Patients were followed up to determine whether they were subsequently admitted to hospital.

RESULTS

Thirty-five per cent of plasma levels were subtherapeutic, and of these, 34% were undetectable. Black ethnicity (P = 0.006) and lower dose (P < 0.001) were significantly associated with subtherapeutic/undetectable plasma levels. Individuals with subtherapeutic/undetectable levels were significantly more likely to be admitted to hospital (P = 0.02).

CONCLUSION

A significant proportion of patients considered treatment-resistant have subtherapeutic antipsychotic plasma levels, and this is associated with subsequent admission. The presence of subtherapeutic plasma levels may suggest a need to address adherence or pharmacokinetic factors as opposed to commencing clozapine treatment. While antipsychotic levels are not recommended for the routine adjustment of dosing, they may assist with the assessment of potential treatment resistance in schizophrenia.

Prevalence of Therapeutic Drug Monitoring for Antidepressants and Antipsychotics in Stockholm, Sweden: A Longitudinal Analysis

Background:

Although therapeutic drug monitoring (TDM) is considered an underused tool in psychiatric care, the prevalence of TDM is largely unknown. The aim of this study was to analyze the prevalence of TDM for antidepressants and antipsychotics during 2006–2013.

Methods:

The study population consisted of individuals ≥5 years of age residing in Stockholm County. The prevalence of TDM for each study year was calculated with the number of individuals in whom TDM had been performed as nominator (extracted from the TDM database at Karolinska University Laboratory) and the number of treated individuals as denominator (extracted from the Swedish Prescribed Drug Register). All data were obtained at the third and the fifth level of the anatomical therapeutic chemical classification system (pharmacological subgroup and chemical substance, respectively). The prevalence of TDM was compared between substances according to the level of TDM recommendation by guidelines.

Results:

For antidepressants, the prevalence of TDM decreased from 0.48% (95% confidence interval, 0.45%–0.52%) in 2006 to 0.36% (0.33%–0.39%) in 2013 (among 133,275 and 162,998 treated individuals, respectively). For antipsychotics, the prevalence of TDM increased from 2.3% (2.2%–2.5%) to 4.1% (3.9%–4.3%) (31,463 and 32,534 treated individuals). For both drug groups, TDM was more common in men than in women. The most frequently analyzed drugs were clozapine, perphenazine, zuclopenthixol, nortriptyline, and flupentixol. Although not reaching statistical significance, the TDM prevalence was greater for substances strongly recommended for TDM than for substances with a lower level of recommendation, median (interquartile range): 5.6% (2.8%–22%) versus 1.1% (0.2%–2.2%), P = 0.063.

Conclusions:

The prevalence of TDM is generally low, more frequent, and increasing for antipsychotics, and more frequent for men and substances where TDM is strongly recommended.

Antipsychotic therapeutic drug monitoring: psychiatrists' attitudes and factors predicting likely future use

BACKGROUND

This study aimed to explore predictive factors for future use of therapeutic drug monitoring (TDM) and to further examine psychiatrists' current prescribing practices and perspectives regarding antipsychotic TDM using plasma concentrations.

METHOD

A cross-sectional study for consultant psychiatrists using a postal questionnaire was conducted in north-west England. Data were combined with those of a previous London-based study and principal axis factor analysis was conducted to identify predictors of future use of TDM.

RESULTS

Most of the 181 participants (82.9%, 95% confidence interval 76.7-87.7%) agreed that 'if TDM for antipsychotics were readily available, I would use it'. Factor analysis identified five factors from the original 35 items regarding TDM. Four of the factors significantly predicted likely future use of antipsychotic TDM and together explained 40% of the variance in a multivariate linear regression model. Likely future use increased with positive attitudes and expectations, and decreased with potential barriers, negative attitudes and negative expectations. Scientific perspectives of TDM and psychiatrist characteristics were not significant predictors.

CONCLUSION

Most senior psychiatrists indicated that they would use antipsychotic TDM if available. However, psychiatrists' attitudes and expectations and the potential barriers need to be addressed, in addition to the scientific evidence, before widespread use of antipsychotic TDM is likely in clinical practice.

Treatment resistant or resistant to treatment? Antipsychotic plasma levels in patients with poorly controlled psychotic symptoms

A large proportion of individuals with schizophrenia show an inadequate response to treatment with antipsychotics. It can be unclear whether this is secondary to subtherapeutic antipsychotic plasma levels or to medication ineffectiveness. The purpose of the present study was to determine the extent of subtherapeutic antipsychotic plasma levels in a group of patients clinically identified as treatment-resistant. In addition we investigated the frequency of antipsychotic plasma level monitoring in standard clinical practice. Antipsychotic plasma levels were measured in 36 patients identified as having treatment-resistant schizophrenia by their treating clinicians. Sixteen (44%) patients showed either undetectable (19%) or subtherapeutic levels (25%), and 20 (56%) patients had levels in the therapeutic range. Subtherapeutic plasma levels were significantly associated with black ethnicity, shorter duration of current treatment and antipsychotics other than olanzapine and amisulpride. Antipsychotic plasma levels had been measured in only one patient in the year prior to our study. We found over one-third of patients identified as treatment-resistant have subtherapeutic antipsychotic levels. This indicates that they may be under-treated rather than treatment-resistant, and thus should receive different management. Currently the measurement of antipsychotic levels may be under-utilised.

Olanzapine and risperidone plasma concentration therapeutic drug monitoring: A feasibility study

BACKGROUND

This study aimed to develop a clinically acceptable method of therapeutic drug monitoring (TDM) for olanzapine and risperidone and to evaluate the feasibility of its implementation.

METHOD

A non-randomised study of inpatients from five Mental Health Trusts was conducted, with a clinical interview at the time of TDM and a subsequent 6-week follow-up review of clinical notes. The TDM intervention comprised: (a) a venous blood sample taken 12 hours post-dose, 7-10 days after drug initiation, and (b) rapid results feedback, with interpretation algorithm guidance.

RESULTS

Thirty-two participants provided samples (19 prescribed olanzapine, 13 risperidone). Twenty-six participants remained on the target drug at study end, with seven experiencing a dose change, for whom only four of the TDM results were confirmed as having been checked. Mean dose increased for olanzapine (0.9 mg/day, range 0-10) and decreased for risperidone (-0.3 mg/day, range -4-3).

CONCLUSION

TDM can be implemented as part of routine clinical practice for both drugs. However, the lack of robust supporting evidence for or against antipsychotic TDM has probably led to a lack of enthusiasm for and interest in the results. Nevertheless, the advent of less invasive measures and the targeting of patients who might be more likely to benefit may facilitate uptake.

Current advances in biosampling for therapeutic drug monitoring of psychiatric CNS drugs

Many CNS drugs are effective for the treatment of psychiatric disorders. Psychotropic drugs work differently, thus clinical outcomes for many patients may be insufficient. For this reason it could be useful the measurement of drug levels for clinical decision-making. Analytical goals in therapeutic drug monitoring (TDM) should be established by selecting the appropriate biological matrix. The aim of this review is to highlight the usefulness of TDM for antiepileptics, antidepressants and antipsychotics, with a focus on current advances in biosampling. The literature on TDM was reviewed up to March 2015. An overview on the use of alternative biological matrices is provided to address the current issues and advances in the field of biosampling for psychiatric CNS drug TDM.

Therapeutic drug monitoring: perspectives of psychiatrists in Turkey

OBJECTIVES

Although the medical and economic implications of therapeutic drug monitoring have been intensely discussed over the past years, little is known about the experiences and attitudes of psychiatrists in their clinical practice. The aim of this study was to investigate psychiatrists' daily practice with therapeutic drug monitoring in Turkey.

METHODS

A nation-wide cross-sectional survey among adult and child psychiatry specialist psychiatrists in Turkey was conducted.

RESULTS

We found that 98.4% (n = 380) of the study participants used TDM in clinical practice and 1.6% (n = 6) did not. However, TDM use is limited to mood stabilizers (lithium 96.3%, valproate 97.6%) to a great extent. Only a small number of psychiatrists perform TDM for other psychotropic drugs, e.g., clozapine 2.4%, tricyclic antidepressants 1.3%, benzodiazepines 1.1%, and selective serotonin reuptake inhibitors 0,8%.

CONCLUSIONS

Most of the psychiatrists in Turkey have a positive attitude toward use of therapeutic drug monitoring although there is also a considerable difficulty to reach services for the therapeutic drug monitoring of psychotropics other than mood stabilizers.

Dried blood spot testing: a novel approach for the therapeutic drug monitoring of ziprasidone-treated patients

Background: A novel analytical approach, based on dried blood spot (DBS) testing, has been developed, validated and applied for the first time to the analysis of ziprasidone (ZPR) for the therapeutic drug monitoring (TDM) of schizophrenic patients. DBS represent a more feasible but reliable matrix, alternative to blood and plasma. Methods: The assays were carried out using an HPLC method with native fluorescence. Blood drops were applied to DBS cards and dried by microwaves, an internal standard solution was added to the DBS and 5-mm punches were cut out for analysis. ZPR was extracted from DBS with methanol, giving good extraction yields, precision and selectivity results. Results: The method was applied with satisfactory results to DBS samples from psychiatric patients to determine ZPR levels for therapy optimization. Conclusion: This innovative methodology provides reliable and significant TDM information, with important advantages over classical blood sampling in terms of collection, storage and processing.