A critical evaluation of the cardiac toxicity of citalopram: part 1

How to Utilize Clinical and Genetic Information for Personalized Treatment of Major Depressive Disorder: Step by Step Strategic Approach

Depression is the single largest contributor to non-fatal health loss and affects 322 million people globally. The clinical heterogeneity of this disorder shows biological correlates and it makes the personalization of antidepressant prescription an important pillar of treatment. There is increasing evidence of genetic overlap between depression, other psychiatric and non-psychiatric disorders, which varies across depression subtypes. Therefore, the first step of clinical evaluation should include a careful assessment of psychopathology and physical health, not limited to previously diagnosed disorders. In part of the patients indeed the pathogenesis of depression may be strictly linked to inflammatory and metabolic abnormalities, and the treatment should target these as much as the depressive symptoms themselves. When the evaluation of the symptom and drug tolerability profile, the concomitant biochemical abnormalities and physical conditions is not enough and at least one pharmacotherapy failed, the genotyping of variants in CYP2D6/CYP2C19 (cytochromes responsible for antidepressant metabolism) should be considered. Individuals with altered metabolism through one of these enzymes may benefit from some antidepressants rather than others or need dose adjustments. Finally, if available, the polygenic predisposition towards cardio-metabolic disorders can be integrated with non-genetic risk factors to tune the identification of patients who should avoid medications associated with this type of side effects. A sufficient knowledge of the polygenic risk of complex medical and psychiatric conditions is becoming relevant as this information can be obtained through direct-to-consumer genetic tests and in the future it may provided by national health care systems.

Trend of antidepressants before, during, and after pregnancy across two decades-A population-based study

INTRODUCTION

Factors that influence antidepressant (AD) prescription and use during pregnancy are multiple including, in particular, the balance between the potential risk of untreated depression and the potential risk of AD treatment. Surveillance of temporal trends of AD use might identify areas requiring further research. We studied the use of ADs before, during, and after pregnancy using national data across two decades in Denmark.

METHODS

We included 1,232,233 pregnancies leading to live birth in Denmark between 1 January 1997 and 31 December 2016. Information on redemption of AD prescriptions was obtained from the Danish National Prescription Register.

RESULTS

We identified 29,504 (2.4%) pregnancies having at least one AD prescription (96,232 AD prescriptions) during pregnancy. The majority redeemed more than one prescription (69.7%) often for a single kind of AD (83.5%), and in 94% of the AD-exposed pregnancies, the estimated duration of treatment was 1 month or longer. Prescription of ADs during pregnancy increased steadily from 0.4% in 1997 to 4.6% in 2011, but decreased thereafter to 3.1% in 2016. The proportion of pregnancies with ADs in 2011 was 6.05-fold higher than that in 1997. The temporal trends in AD prescription in the years before and after pregnancy were similar to the trend during pregnancy. The decreasing use of ADs during pregnancy after 2011 was mainly driven by a decrease in the use of selective serotonin reuptake inhibitors (SSRIs), especially citalopram, the main type of SSRIs used in Denmark.

CONCLUSION

Prescription of ADs during pregnancy in Denmark increased steadily from 1997 to 2011 but decreased sharply thereafter. More research is needed to show whether the same trend exists in other populations, like women of reproductive age, men of reproductive age, and old people, and other countries. We also need to find explanation for the decreasing trend in recent years and potential risk for untreated depression.

Antidepressant Controlled Trial For Negative Symptoms In Schizophrenia (ACTIONS): a double-blind, placebo-controlled, randomised clinical trial

BACKGROUND

Negative symptoms of schizophrenia represent deficiencies in emotional responsiveness, motivation, socialisation, speech and movement. When persistent, they are held to account for much of the poor functional outcomes associated with schizophrenia. There are currently no approved pharmacological treatments. While the available evidence suggests that a combination of antipsychotic and antidepressant medication may be effective in treating negative symptoms, it is too limited to allow any firm conclusions.

OBJECTIVE

To establish the clinical effectiveness and cost-effectiveness of augmentation of antipsychotic medication with the antidepressant citalopram for the management of negative symptoms in schizophrenia.

DESIGN

A multicentre, double-blind, individually randomised, placebo-controlled trial with 12-month follow-up.

SETTING

Adult psychiatric services, treating people with schizophrenia.

PARTICIPANTS

Inpatients or outpatients with schizophrenia, on continuing, stable antipsychotic medication, with persistent negative symptoms at a criterion level of severity.

INTERVENTIONS

Eligible participants were randomised 1 : 1 to treatment with either placebo (one capsule) or 20 mg of citalopram per day for 48 weeks, with the clinical option at 4 weeks to increase the daily dosage to 40 mg of citalopram or two placebo capsules for the remainder of the study.

MAIN OUTCOME MEASURES

The primary outcomes were quality of life measured at 12 and 48 weeks assessed using the Heinrich's Quality of Life Scale, and negative symptoms at 12 weeks measured on the negative symptom subscale of the Positive and Negative Syndrome Scale.

RESULTS

No therapeutic benefit in terms of improvement in quality of life or negative symptoms was detected for citalopram over 12 weeks or at 48 weeks, but secondary analysis suggested modest improvement in the negative symptom domain, avolition/amotivation, at 12 weeks (mean difference -1.3, 95% confidence interval -2.5 to -0.09). There were no statistically significant differences between the two treatment arms over 48-week follow-up in either the health economics outcomes or costs, and no differences in the frequency or severity of adverse effects, including corrected QT interval prolongation.

LIMITATIONS

The trial under-recruited, partly because cardiac safety concerns about citalopram were raised, with the 62 participants recruited falling well short of the target recruitment of 358. Although this was the largest sample randomised to citalopram in a randomised controlled trial of antidepressant augmentation for negative symptoms of schizophrenia and had the longest follow-up, the power of statistical analysis to detect significant differences between the active and placebo groups was limited.

CONCLUSION

Although adjunctive citalopram did not improve negative symptoms overall, there was evidence of some positive effect on avolition/amotivation, recognised as a critical barrier to psychosocial rehabilitation and achieving better social and community functional outcomes. Comprehensive assessment of side-effect burden did not identify any serious safety or tolerability issues. The addition of citalopram as a long-term prescribing strategy for the treatment of negative symptoms may merit further investigation in larger studies.

FUTURE WORK

Further studies of the viability of adjunctive antidepressant treatment for negative symptoms in schizophrenia should include appropriate safety monitoring and use rating scales that allow for evaluation of avolition/amotivation as a discrete negative symptom domain. Overcoming the barriers to recruiting an adequate sample size will remain a challenge.

TRIAL REGISTRATION

European Union Drug Regulating Authorities Clinical Trials (EudraCT) number 2009-009235-30 and Current Controlled Trials ISRCTN42305247.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 29. See the NIHR Journals Library website for further project information.

Evaluation of QTc prolongation and dosage effect with citalopram

Introduction:

Recently, controversy has surrounded a 2011 Food and Drug Administration warning against using citalopram at doses >40 mg/day due to QTc prolonging effects.

Methods:

Patients ≥18 years old at the VA North Texas Health Care System were included in this retrospective review if they had received at least 1 prescription for a 30-day supply of citalopram between January 1, 2007, and February 29, 2012, and had a baseline electrocardiogram (ECG) within 1 year before initiation or dose increase of citalopram and at least 1 repeat ECG within 3 months after citalopram initiation or dose increase. The primary endpoint was the prevalence of QTc prolongation (QTc interval ≥470 ms for men and ≥480 ms for women) after initiation or a dose increase of citalopram. For secondary objectives, Fisher exact tests were used determine if there was a dose-dependent difference in prevalence of QTc prolongation among the whole study sample and among the subgroup of patients ≥60 years old.

Results:

Among the entire study sample, QTc prolongation was identified in 12 patients (16.4%) after initiation or a dose increase of citalopram. In the subgroup of patients ≥60 years old, QTc prolongation was identified in 7 patients (21.9%). Prevalence of QTc prolongation increased with dose in the entire study population (P = .016) and in patients ≥60 years (not significant).

Discussion:

This retrospective study suggests that citalopram produces a dose-dependent increase in QTc interval.

The effectiveness and limitations of regulatory warnings for the safe prescribing of citalopram

Background

Citalopram is the most commonly prescribed antidepressant in Canada. Concerns have been raised about its cardiac safety, and a dose-dependent prolongation of the QT interval has been documented. Drug interactions involving concomitant use of other medications that prolong the QT interval or increase citalopram levels by interfering with its metabolism increase the cardiac risk. Regulatory bodies (Health Canada and the US Food and Drug Administration) issued warnings and required labeling changes in 2011/2012, suggesting maximum citalopram doses (<40 mg for those <65 years; <20 mg for those ≥65 years) and avoiding drug interactions that increase cardiac risk. The purpose of this study is to assess the impact of these warnings on citalopram prescribing practices.

Methods

A quasi-experimental interrupted time series analysis was conducted using all citalopram prescribing data from the population of Manitoba, Canada from 1999 to 2014. This allowed for the examination of high-dose prescribing (above regulatory warning levels) and the number of interacting medications per citalopram prescription.

Results

There was a dramatic decline in the prescribing of high doses in both age groups, with a 64.8% decline in those <65 years and 33.6% in those ≥65 years. Segmented regression models indicated significant breakpoints in the third quarter of 2011 for both age groups (P<0.0001), corresponding to the time the regulatory warnings were issued. There appeared to be no impact of the warnings on the prescribing of interacting medications. The number of interacting medications actually increased in the postwarning period (<65, 0.78–0.81 interactions per citalopram prescription; ≥65, 0.93–0.94, P<0.001).

Conclusion

Regulatory changes appear to have produced an important reduction in the high-dose prescribing of citalopram. In contrast to this relatively simple dosage change, there was no indication that the more complex issue of resolving drug–drug interactions was impacted by regulatory warnings.

QTc Prolongation in Veterans With Heroin Dependence on Methadone Maintenance Treatment

Background:

QTc prolongation and Torsade de Ppointes have been reported in patients on methadone maintenance.

Objectives:

In this study, QTc was compared before and after the veteran (n = 49) was on a stable dosage of methadone for 8.72 ± 4.50 years to treat heroin dependence. Risk factors were correlated with the QTc once the veteran was on a stable dose of methadone. Differences in the clinical risk factors in subgroups of veterans with below and above mean QTc change was compared.

Patients and Methods:

ECG data was obtained from a 12-lead electrocardiogram (pre-methadone and on methadone) on 49 veterans. Data and risk factors were retrospectively collected from the medical records.

Results:

The mean QTc at baseline (pre-methadone) was 426 ± 34 msec and after being on methadone for an average of 8.72 ± 4.50 years was significantly higher at 450 ± 35 msec. No significant relationships were found between QTc prolongation and risk factors except for calcium. The methadone dosage was significantly higher in veterans with a QTc change above the mean change of ≥ 24 msec (88.48 ± 27.20 mg v.s 68.96 ± 19.84 mg). None of the veterans experienced cardiac arrhythmias.

Conclusions:

The low complexity of medical co-morbidities may explain the lack of a significant correlation between any risk factor with the QTc except calcium and methadone dosage. The absence of TdP may be explained by the low prevalence of QTc values > 500 msec as well as the retrospective design of the study. During long-term methadone treatment, there was a slight increase in the QTc interval but we did not find evidence of increased cardiac toxicity as a reason for treatment termination.

Implementation of warnings from Dear Doctor Letters (Rote-Hand-Briefe): an analysis of medication data from a large cohort of elderly patients

BACKGROUND

Dear Doctor Letters (also known as Direct Healthcare Professional Communications) inform physicians about significant newly discovered drug risks and about measures to take to reduce these risks. How far these warnings actually influence prescribing behavior is unclear.

METHOD

The Geriatrics in Bavaria-Database (GiB-DAT, Geriatrie in Bayern Datenbank) collects data from more than 50 centers offering inpatient geriatric health care. Based on GiB-DAT data, the discharge medication of 76 568 patients (81 ± 8 years, 67% women) was recorded in a standardized manner and analyzed for the implementation of information contained in two Dear Doctor Letters about the risks of dose-related or drug interaction-related QT interval prolongation caused by citalopram or escitalopram.

RESULTS

Patients were discharged with a median of 8 drugs. In the four quarters of 2012 following release of the Dear Doctor Letters, in comparison to the four quarters before their publication, a marked drop from 9.8% to 4.1% was seen in prescriptions for >20 mg/day citalopram--a dosage no longer recommended in elderly patients--and a similar drop from 23.6% to 12.8% in prescriptions for >10 mg/day escitalopram (p<0.0001). Co-prescription of either of these two drugs with other QT interval-prolonging drugs, which was now contraindicated, remained almost unchanged (citalopram: 19.3% [95% confidence interval (CI): 17.9-20.9%] versus 18.4% [95% CI: 17.0-19.8%]; escitalopram: 17.6% [95% CI: 15.8-19.6%] versus 17.1% [95% CI: 14.5-19.9%]).

CONCLUSION

Simple information in Dear Doctor Letters, such as a reduction of the maximum daily dose, was better implemented than complicated information regarding contraindicated co-medication. Quality assurance systems such as the GiB-DAT network make it possible to identify problems of this kind. Licensing authorities and pharmaceutical companies should should improve the clinical usability, e.g., by providing official reference lists of drugs with safety warnings.

A comparison of the risk of QT prolongation among SSRIs

OBJECTIVE

To report QT prolongation potential in selective serotonin reuptake inhibitors (SSRIs) in order to advise clinicians on safe use of SSRIs other than citalopram in light of citalopram warnings.

DATA SOURCES

Primary literature and case reports were identified through a systematic search. Data from drug manufacturers, package inserts, and the ArizonaCERT database were also utilized.

STUDY SELECTION AND DATA EXTRACTION

English-language studies and case reports were included.

DATA SYNTHESIS

Studies demonstrate possible dose-related clinically significant QT prolongation with escitalopram. Fluoxetine, fluvoxamine, and sertraline at traditional doses demonstrate a lack of clinically significant increases in QTc in the majority of studies. Further, paroxetine monotherapy shows a lack of clinically significant QTc prolongation in all studies. However, case reports or reporting tools still link these SSRIs with QTc prolongation. Fluoxetine, escitalopram, and sertraline used in post-acute coronary syndrome patients did not demonstrate risk of QTc prolongation.

CONCLUSION

For clinicians who choose not to use citalopram due to recent Food and Drug Administration (FDA) recommendations, other antidepressants within this class may be considered. When citalopram is not utilized based on risk factors for TdP, use of escitalopram is not likely the safest alternative. Based on current literature, fluoxetine, fluvoxamine, and sertraline appear to have similar, low risk for QT prolongation, and paroxetine appears to have the lowest risk. However, there are significant limitations in interpreting the studies, including varying definitions of significant QT prolongation. Therefore, choice of an alternative SSRI should be based on individual risk factors for arrhythmias and other patient-specific factors.

Citalopram, QTc interval prolongation, and torsade de pointes. How should we apply the recent FDA ruling?

Recently, both the manufacturer of citalopram and the US Food and Drug Administration have warned health care providers and patients about new information implicating drug-induced QTc interval prolongation and torsade de pointes when using citalopram in doses >40 mg/day. This warning is not placed in the context of either benefits or risks in real-world clinical practice, leaving clinicians with an untenable choice between depriving patients of high-dose citalopram or malpractice litigation. We reviewed the literature and found no cases of citalopram-induced sudden cardiac death among patients taking up to 60 mg/day of citalopram and free of risk factors for QTc interval prolongation and torsade de pointes. Because psychotropic drug-induced sudden cardiac death is an outlier in the absence of identified risk factors for QTc interval prolongation and torsade de pointes, we do not believe current Phase 3 and Phase 4 studies provide sufficient information to limit current prescribing practices for citalopram (20 mg to 60 mg/day). We urge drug manufacturers and regulatory agencies to periodically publish full case reports of psychotropic drug-induced QTc interval prolongation, torsade de pointes, and sudden cardiac death so that clinicians and investigators may better understand the clinical implications of prescribing such drugs as citalopram.

FDA drug safety communications: a narrative review and clinical considerations for older adults

BACKGROUND

The US Food and Drug Administration (FDA) has new regulatory authorities intended to enhance drug safety monitoring in the postmarketing period. This has resulted in an increase in communication from the FDA in recent years about the safety profile of certain drugs. It is important to stay abreast of the current literature on drug risks to effectively communicate these risks to patients, other health care providers, and the general public.

OBJECTIVE

To summarize 4 new FDA drug safety communications by describing the evidence supporting the risks and the clinical implications for older adults.

METHODS

The FDA Web site was reviewed for new drug safety communications from May 2011 to April 2012 that would be relevant to older adults. Approved labeling for each drug or class was obtained from the manufacturer, and PubMed was searched for primary literature that supported the drug safety concern.

RESULTS

FDA drug safety communications for 4 drugs were chosen because of the potential clinical importance in older adults. A warning for citalopram was made because of potential problems with QT prolongation in patients taking less than 40 mg per day. The evidence suggests minor changes in QT interval. Given the flat dose-response curve in treating depression with citalopram, the new 20-mg/d maximum dose in older adults is sensible. Another warning was made for proton pump inhibitors (PPIs) and an increased risk of Clostridium difficile infection. A dose-response relationship was found for this drug risk. With C. difficile infections on the rise in older adults, along with other safety risks of PPI therapy, PPIs should only be used in older adults indicated for therapy for the shortest duration possible. In addition, a warning about dabigatran was made. There is strong evidence from a large clinical trial, as well as case reports, of increased bleeding risk in older adults taking dabigatran, especially in older adults with decreased renal function. This medication should be used with caution in older adults. Finally, several warnings were made about statins. Routine periodic monitoring of liver enzymes does not appear to be effective in detecting or preventing serious liver injury from statin use; thus, liver enzymes are no longer recommended to be routinely monitored. Statin-induced cognitive changes are rare, and insufficient evidence is currently available to establish causality. Statins appear to moderately increase the risk of developing diabetes (versus placebo), and regular screening for diabetes should be considered, especially for patients taking high-dose statins and patients with multiple risk factors for diabetes.

CONCLUSION

FDA drug safety communications incorporate complex methodologies that investigate the risks (and relative benefits) of medication therapy. Clinicians caring for older adults need to be aware of the most current evidence behind these drug risks to effectively communicate with and care for their patients.

A question about the potential cardiac toxicity of escitalopram

Previous reviews have focused on the potential cardiac toxicity of the racemic drug citalopram (Celexa(®)). Evaluating the safety of escitalopram (Lexapro(®)) is an important issue to consider, since it is the S-enantiomer of citalopram. Escitalopram has a small effect on the QTc interval. A prolonged QTc was seen in 2% to 14% of escitalopram overdose cases, without serious cardiac sequelae. The QTc prolongation effect of citalopram in beagle dogs has been attributed to the minor metabolite racemic didemethylcitalopram (DDCT). Whether the escitalopram minor metabolite S-DDCT has this effect is not known. Concentrations of S-DDCT are lower than DDCT, but for a broad range of doses of escitalopram and citalopram, the S-DDCT and DDCT concentrations are well below the QTc prolonging concentrations reported in dogs. There is no strong evidence from human and animal studies that the cardiac safety of escitalopram is significantly superior to that of citalopram.

A critical evaluation of the cardiac toxicity of citalopram: part 2

In August 2011, the U.S. Food and Drug Administration issued a drug safety communication that the antidepressant drug citalopram (Celexa®) should not be used at dosages greater than 40 mg per day (or greater than 20 mg per day for patients 60 and older) because higher doses have been associated with abnormal heart rhythms. Clinical studies using citalopram in patients with cardiac disease and in older patients do not confirm such a risk. The major metabolite of citalopram is demethylcitalopram, which is subsequently metabolized to the minor metabolite didemethylcitalopram (DDCT). High DDCT concentrations have been associated with QT interval prolongation in beagle dogs. Therapeutic drug monitoring study data suggest that routine or even high oral doses of citalopram are unlikely to result in cardiotoxic concentrations of the DDCT metabolite. Based on evidence taken from a wide variety of studies, the citalopram dose limitations described in the safety announcement do not have strong clinical justification.