A comparative study of non-fatal self-poisoning with antidepressants relative to prescribing in three centres in England

Suspected suicides and nonfatal suicide attempts involving antidepressants reported to United States poison control centers, 2000-2020

CONTEXT/OBJECTIVE

This study investigates characteristics of suspected suicides and nonfatal suicide attempts involving antidepressants among individuals 13 years and older reported to US poison control centers from 2000-2020.

METHODS

Data from the National Poison Data System were retrospectively analyzed.

RESULTS/DISCUSSION

There were 744,853 suspected suicides and nonfatal suicide attempts among individuals 13 years and older involving antidepressants as the first-ranked substance during the study period. Teenagers accounted for 28.6% of cases and females represented 68.7% of cases. From 2000-2019, the rate of calls received by US poison control centers for suspected suicides and nonfatal suicide attempts involving antidepressants per 100,000 US population 13 years and older increased from 17.4 to 28.4 (p < 0.0001); however, teenagers experienced the largest increase in rate from 30.4 in 2000 to 83.3 in 2019, with a rapid rate increase beginning in 2011. Individuals 60 years and older were more likely to be admitted to a health care facility than teenagers (OR: 2.18, 95% CI: 2.12-2.25). A serious medical outcome was documented in 36.3% of cases, with death occurring in 0.2% of cases. A serious medical outcome was more than twice as likely (OR: 2.57, 95% CI: 2.51-2.64) and death was 16 times more likely (OR: 16.19, 95% CI: 13.29-19.73) to occur among individuals 60 years or older than teenagers. SSRIs were most often involved (41.0%) in cases; however, TCAs had the largest proportion of serious medical outcomes (59.8%). TCAs were more likely to result in a serious medical outcome (OR: 4.36, 95% CI: 4.29-4.43) or death (OR: 12.56, 95% CI: 10.91-14.46) than SSRIs.

CONCLUSIONS

The increase in the rate of suspected suicides and nonfatal suicide attempts involving antidepressants reported to US poison control centers, particularly among teenagers, emphasizes the need for increased prevention efforts. The greater severity of medical outcomes among older adults also warrants attention.

Multivariate analysis applied in dataset of Poison Control Center of São Paulo, Brazil

Multivariate analysis techniques could be used to identify possible intercorrelations in intoxications cases. The statistical analyses used were a multiple logistic regression, multiple correspondence analysis, principal component and hierarchical cluster analysis. Of the 320 samples analysed, 192 samples were positive for some of the investigated toxic agents, of which 100 were positive for ethanol and 131 were positive for other substances. It was possible to group the patients into 3 clusters, which appears 66.5% of this information in the three first factorial axes. On the first axis, the male patients were separated from the female patients. Patients exposed to drugs, between 30 and 39 years old were grouped in the same cluster. On the second factorial axis, patients who were intoxicated with ethanol and who became intoxicated with diazepam were grouped. This work contributed to the mapping of intoxication cases at the Poison Control Centre of the São Paulo city, Brazil (CCI-SP) and serves as an initial study for the creation of a database that could be updated constantly and thus could provide a toxicovigilance system for educational policies.

Clinical management following self-harm in a UK-wide primary care cohort

BACKGROUND

Little is known about the clinical management of patients in primary care following self-harm.

METHODS

A descriptive cohort study using data from 684 UK general practices that contributed to the Clinical Practice Research Datalink (CPRD) during 2001-2013. We identified 49,970 patients with a self-harm episode, 41,500 of whom had one complete year of follow-up.

RESULTS

Among those with complete follow-up, 26,065 (62.8%, 62.3-63.3) were prescribed psychotropic medication and 6318 (15.2%, 14.9-15.6) were referred to mental health services; 4105 (9.9%, CI 9.6-10.2) were medicated without an antecedent psychiatric diagnosis or referral, and 4,506 (10.9%, CI 10.6-11.2) had a diagnosis but were not subsequently medicated or referred. Patients registered at practices in the most deprived localities were 27.1% (CI 21.5-32.2) less likely to be referred than those in the least deprived. Despite a specifically flagged NICE 'Do not do' recommendation in 2011 against prescribing tricyclic antidepressants following self-harm because of their potentially lethal toxicity in overdose, 8.8% (CI 7.8-9.8) of individuals were issued a prescription in the subsequent year. The percentage prescribed Citalopram, an SSRI antidepressant with higher toxicity in overdose, fell sharply during 2012/2013 in the aftermath of a Medicines and Healthcare products Regulatory Agency (MHRA) safety alert issued in 2011.

CONCLUSIONS

A relatively small percentage of these vulnerable patients are referred to mental health services, and reduced likelihood of referral in more deprived localities reflects a marked health inequality. National clinical guidelines have not yet been effective in reducing rates of tricyclic antidepressant prescribing for this high-risk group.

Antidepressant and QT interval prolongation, how should we look at this issue? Focus on citalopram

INTRODUCTION

Evidence increasingly points to the potential development of harmful cardiac side effects concomitant with the use of a number of psychotropic drugs, primarily traditional antipsychotics and tricyclic antidepressants.

AREAS COVERED

The US Food and Drug Administration announced safety warnings associated with the use of citalopram with QT interval prolongation in 2011 and 2012. This paper explores the clinical background of QT interval prolongation, clinical data related to antidepressants and QT interval prolongation, the clinical implications of safety issues associated with the use of antidepressants and future research directions.

EXPERT OPINION

Currently available evidence proposes that citalopram may not be definitely associated with the increase of cardiac mortality, although it should be related with increase of QT prolongation. A firm consensus regarding the cardiac safety issues associated with antidepressants has to be established in near future. Hence, the choice of an individual antidepressant regarding cardiac safety issues should be based on multiple factors; clinicians may need to select the best available antidepressant for each individual based on that patient's vulnerability, the proven efficacy and safety of each agent and a reasonable benefit:risk ratio, based on currently available findings.

A review of the suitability of duloxetine and venlafaxine for use in patients with depression in primary care with a focus on cardiovascular safety, suicide and mortality due to antidepressant overdose

Depression and anxiety disorders are among the most common disorders treated by general practitioners (GPs) in the UK. Since both disorders are associated with a significantly increased risk of suicide, including with antidepressant overdose, the safety of antidepressants in overdose is of paramount importance. Numerous updates relating to antidepressant safety have been issued by regulators in the UK which may have eroded GP confidence in antidepressants. Venlafaxine, a serotonin nor adrenaline reuptake inhibitor (SNRI) had primary care prescribing restrictions placed on it in 2004 due to concerns about cardiotoxicity and mortality in overdose. Although a review of the evidence led to a reversal of the majority of restrictions in 2006, evidence suggests GPs may still be cautious in their prescribing of venlafaxine and possibly other SNRI antidepressants for patients with depression and anxiety disorders. This paper reviews the evidence pertaining to the safety of SNRI antidepressants from a perspective of cardiovascular safety and overdose. The currently available evidence suggests a marginally higher toxicity of venlafaxine in overdose compared with another SNRI duloxetine and the selective serotonin reuptake inhibitors (SSRIs), although this may be related to differential patterns of prescribing in high-risk patients. Based on this review SNRIs have a positive risk benefit profile in the treatment of depression and generalized anxiety disorder in primary care, especially as second-line agents to SSRIs.

Epidemiology and nature of self-harm in children and adolescents: findings from the multicentre study of self-harm in England

We examined epidemiology and characteristics of self-harm in adolescents and impact of national guidance on management. Data were collected in six hospitals in three centres between 2000 and 2007 in the Multicentre Study of Self-harm in England. Of 5,205 individuals (7,150 episodes of self-harm), three-quarters were female. The female:male ratio in 10-14 year-olds was 5.0 and 2.7 in 15-18 year-olds. Rates of self-harm varied somewhat between the centres. In females they averaged 302 per 100,000 (95 % CI 269-335) in 10-14 year-olds and 1,423 (95 % CI 1,346-1,501) in 15-18 year-olds, and were 67 (95 % CI 52-82) and 466 (95 % CI 422-510), respectively, in males. Self-poisoning was the most common method, involving paracetamol in 58.2 % of episodes. Presentations, especially those involving alcohol, peaked at night. Repetition of self-harm was frequent (53.3 % had a history of prior self-harm and 17.7 % repeated within a year). Relationship problems were the predominant difficulties associated with self-harm. Specialist assessment occurred in 57 % of episodes. Self-harm in children and adolescents in England is common, especially in older adolescents, and paracetamol overdose is the predominant method. National guidance on provision of psychosocial assessment in all cases of self-harm requires further implementation.

Psychosocial assessment and repetition of self-harm: the significance of single and multiple repeat episode analyses

BACKGROUND

Self-harm is a common reason for presentation to the Emergency Department. An important question is whether psychosocial assessment reduces risk of repeated self-harm. Repetition has been investigated with survival analysis using various models, though many are not appropriate for recurrent events.

METHODS

Survival analysis was used to investigate associations between psychosocial assessment following an episode of self-harm and subsequent repetition, including (i) one repeat, and (ii) recurrent repetition (≤5 repeats) using (a) an independent episodes model, and (b) a stratified episodes model based on a conditional risk set. Data were from the Multicentre Study on Self-harm in England, 2000 to 2007.

RESULTS

Psychosocial assessment following an index episode of self-harm was associated with a 51% (95% CI 42%-58%) decreased risk of a repeat episode in persons with no psychiatric treatment history, and 26% (95% CI 8%-34%) decreased risk in those with a treatment history. For recurrent repetition, assessment was associated with a 57% (95% CI 51%-63%) decreased risk of repetition assuming independent episodes, and 13% (95% CI 1%-24%) decreased risk accounting for ordering and correlation of episodes by the same person (stratified episodes model). All models controlled for age, gender, method, history of self-harm, and centre differences.

LIMITATIONS

Some missing data on psychiatric treatment for non-assessed patients.

CONCLUSIONS

Psychosocial assessment appeared to be beneficial in reducing the risk of repetition, especially in the short-term. Findings for recurrent repetition were highly dependent on model assumptions. Analyses should fully account for ordering and correlation of episodes by the same person.

Toxicity of antidepressants: rates of suicide relative to prescribing and non-fatal overdose

BACKGROUND

Self-poisoning is a common method of suicide and often involves ingestion of antidepressants. Information on the relative toxicity of antidepressants is therefore extremely important.

AIMS

To assess the relative toxicity of specific tricyclic antidepressants (TCAs), a serotonin and noradrenaline reuptake inhibitor (SNRI), a noradrenergic and specific serotonergic antidepressant (NaSSA), and selective serotonin reuptake inhibitors (SSRIs).

METHOD

Observational study of prescriptions (UK), poisoning deaths involving single antidepressants receiving coroners' verdicts of suicide or undetermined intent (England and Wales) and non-fatal self-poisoning episodes presenting to six general hospitals (in Oxford, Manchester and Derby) between 2000 and 2006. Calculation of fatal toxicity index based on ratio of rates of deaths to prescriptions, and case fatality based on ratio of rates of deaths to non-fatal self-poisonings.

RESULTS

Fatal toxicity and case fatality indices provided very similar results (rho for relative ranking of indices 0.99). Case fatality rate ratios showed greater toxicity for TCAs (13.8, 95% CI 13.0-14.7) than the SNRI venlafaxine (2.5, 95% CI 2.0-3.1) and the NaSSA mirtazapine (1.9, 95% CI 1.1-2.9), both of which had greater toxicity than the SSRIs (0.5, 95% CI 0.4-0.7). Within the TCAs, compared with amitriptyline both dosulepin (relative toxicity index 2.7) and doxepin (2.6) were more toxic. Within the SSRIs, citalopram had a higher case fatality than the other SSRIs (1.1, 95% CI 0.8-1.4 v. 0.3, 95% CI 0.2-0.4).

CONCLUSIONS

There are wide differences in toxicity not only between classes of antidepressants, but also within classes. The findings are relevant to prescribing decisions, especially in individuals at risk, and to regulatory policy.