Antidepressant-related deaths and antidepressant prescriptions in England and Wales, 1998-2000

Cocaine/crack cocaine consumption, treatment demand, seizures, related offences, prices, average purity levels and deaths in the UK (1990 - 2004)

A recent trend of escalating use of cocaine/crack cocaine was observed in the UK. The number of mentions on death certificates; last year use of cocaine; treatment demand, number of drug offenders, seizures, prices and average purity levels were the indicators used for this descriptive and correlational study. Figures (1990-2004) were taken from official UK sources. A total of 1022 cocaine/crack cocaine death mentions (i.e. deaths from any cause where the presence of cocaine/crack cocaine was also detected) were identified, with cocaine/crack cocaine being the sole drug mentioned in 36% of cases. The number of cocaine/crack cocaine death mentions showed a year-on-year increase and correlated positively with the following cocaine (powder) figures: last year use (p < 0.001); number of offenders (p < 0.001) and number of seizures (p < 0.001), but correlated negatively with price (p < 0.001). Furthermore, the number of cocaine/crack cocaine death mentions correlated positively with the number of crack offenders (p < 0.001) and seizures (p < 0.001), but correlated negatively with both crack purity ( p < 0.001) and price (p < 0.05). With conditions of increasing drug availability having been met in the UK, decrease in cocaine prices were associated with higher consumption levels and this, in turn, contributed to the increase in number of cocaine-related fatalities. There are limitations with the information collected, since no distinction is usually made on medical death certificates between cocaine and crack cocaine. The present study being an ecological one, it proved difficult to address the role of confounding variables that may well explain some of the associations observed.

Depressive Störungen

Das Spektrum depressiver Erkrankungen macht den Hauptteil affektiver Störungen aus und gehört mit einer Inzidenz von ca. 8–20% zu den häufigsten psychischen Erkrankungen. Depressionen werden nach wie vor zu selten einer adäquaten Therapie (Antidepressiva, störungsspezifische Psychotherapie wie z. B. kognitive Verhaltenstherapie) zugeführt.

Limitations of current medical treatments for depression: disturbed circadian rhythms as a possible therapeutic target

The proportion of diagnosed depressives prescribed antidepressants has increased markedly over the last 20 years, mainly following the introduction of the selective serotonin reuptake inhibitors. However, currently available antidepressants have notable limitations, relating to their only moderate efficacy relative to placebo, relatively slow onset of action, possible withdrawal symptoms, and problems of compliance. Sleep disturbances are often used to identify newly presenting depressive patients, and may be part of a more general alteration of bodily rhythms. There are links between pharmacological treatments and circadian rhythms in depression, which might represent another, new option for the development of a therapeutic approach to depression treatment. Many antidepressants affect sleep, some are sedative, and others have been used specifically in severely insomniac depressives. Disturbances in circadian rhythms may be an integral part of depressive mechanisms, and normalising them via an innovative mechanism of antidepressant action may be a fruitful avenue in the search for improved antidepressant agents.

Channelling of SSRIs and SNRIs use in the Tayside population, Scotland

PURPOSE

To compare the user profiles of the two classes of drug, using the Tayside Medicines Monitoring Unit (MEMO) record-linkage database.

METHODS

A cohort study was carried out in the population of Tayside in Scotland. A total of 13 901 selective serotonin re-uptake inhibitor (SSRI) users and 1417 selective norepinephrine re-uptake inhibitor (SNRI) users were identified during the period of December 2000 to November 2001. A logistic regression model was used to assess the association between drug use and patients profiles and a Cox regression model was employed to examine the effect of drug use and mortality outcome.

RESULTS

Compared to SNRI patients, SSRI patients were significantly older (28.8% >/= 60 year vs. 26.2%), more likely to be female (70.9% vs. 67.8%), had more cardiovascular disease history (10.1% vs. 8.5%), but were less deprived (9.7% in the highest deprivation category vs. 12.4%), had less digestive disease (27.9% vs. 31.0%) and less history of drug overdose hospitalisation (7.2% vs. 11.9%). SNRI patients had more drug switching than SSRI patients (62.0% for recent users, 33.2% for prevalent users vs. 39.1%, 26.1%, respectively). The age-standardised mortality rates during the follow-up period until December 2003 were 5.3% for SSRI and 5.9% for SNRI users.

CONCLUSION

There was clear evidence that SSRI and SNRI were used in patient groups with different characteristics. This channelling sometimes favoured an improved mortality outcome and sometimes favoured a worse outcome. Overall there was no mortality difference between the two classes of drugs.

Cardiovascular toxicity due to venlafaxine poisoning in adults: a review of 235 consecutive cases

AIMS

Venlafaxine may increase the risk of arrhythmia in certain patients. We sought to characterize the cardiovascular effects of venlafaxine overdose in adults.

METHODS

A retrospective casenote review of patients admitted to the Royal Infirmary of Edinburgh between January 2000 and June 2006. Haemodynamic and electrocardiographic data were examined in the whole group and a subset that ingested venlafaxine alone.

RESULTS

Two hundred and thirty-five patients (65 men) with median (interquartile range) age 34 years (27-43 years) had ingested venlafaxine 1500 mg (919-2800 mg). Tachycardia (40.0%), high blood pressure (28.4%) and mydriasis (36.6%) were common. Corrected QT >450 ms occurred in seven men (11.1%) and 17 women (10.5%) and transient arrhythmia in three patients. There was a positive correlation between stated quantity of venlafaxine ingested and heart rate [rho = 0.195, 95% confidence interval (CI) 0.054, 0.328] and QTc (rho = 0.314, 95% CI 0.089, 0.509).

CONCLUSIONS

Venlafaxine overdose is associated with sympathomimetic cardiovascular effects and prolonged QTc, irrespective of coingested drugs. These mechanisms might pose an increased risk of arrhythmia and require further exploration.

Risk of acute liver injury associated with the use of drugs: a multicentre population survey

BACKGROUND

Acute liver injury of uncertain aetiology is often drug related and quantitative information about the associated risk is scarce.

AIM

To estimate the risk of acute liver injury associated with the use of drugs.

METHODS

In a population survey study, 126 cases of acute liver injury were prospectively assembled from January 1993 to December 1999, in patients over 15 years of age, in 12 hospitals in Barcelona (Spain). We estimated the relative risk for each drug as the ratio between the incidence of acute liver injury among the exposed population to the drug and the incidence of acute liver injury among those not exposed to it. Drug consumption data were used to estimate the exposed population.

RESULTS

Isoniazid, pyrazinamide, rifampicin, amoxicillin with clavulanic acid, erythromicin, chlorpromazine, nimesulide, and ticlopidine presented the highest risk (point relative risk > 25). Amoxicillin, metoclopramide, captopril and enalapril, furosemide, hydrochlorothiazide, fluoxetine, paroxetine, diazepam, alprazolam, lorazepam, metamizole, low-dose acetylsalicylic acid and salbutamol showed the lowest risk (point relative risk < 5).

CONCLUSIONS

This study provides a risk estimation of serious liver disease for various drugs that will be useful in its diagnosis and management, and when comparing with the drug therapeutic benefit in each indication. Some observed associations would be worth specific studies.

The burden of severe depression: a review of diagnostic challenges and treatment alternatives

Among the factors making recognition of severe depression problematic for clinicians are the heterogeneous nature of the condition, lack of standardized definitions, and concomitant comorbidities that confound differential diagnosis of symptoms. The spectrum of severity in depressive disorders is extraordinarily broad, and severity assessment is comprised of several metrics including symptom intensity, diagnostic subtypes, suicidality risk, and hospitalization status. The overall diagnosis is achieved through consideration of symptom types and severities together with the degree of functional impairment as assessed by the psychiatric interview. It is likely that no single fundamental neurobiological defect underlies severe depression. The chronicity and heterogeneity of this disorder lead to frequent clinic visits and a longer course of treatment; therefore, successful approaches may require an arsenal of treatments with numerous mechanisms of action. The categories of drugs used to treat severe depression are detailed herein, as are several non-pharmacologic options including a number of experimental treatments. Pharmacotherapies include tricyclic antidepressants, selective serotonin reuptake inhibitors, atypical antidepressants such as serotonin-norepinephrine reuptake inhibitors and monoamine oxidase inhibitors, and combination and augmentation therapies. Drugs within each class are not equivalent, and efficacy may vary with symptom severity. Patient adherence makes tolerability another critical consideration in antidepressant choice. The role of non-pharmacological treatments such as electroconvulsive therapy, vagus nerve stimulation, transcranial magnetic stimulation, and deep brain stimulation remain active avenues of investigation. Improved knowledge and treatment approaches for severe depression are necessary to facilitate remission, the ideal treatment goal.

Bipolar depression: diagnostic and treatment considerations

Bipolar affective disorder is a recurrent, disabling, and potentially lethal illness that typically begins early in life. Although the disorder is defined by the manic and hypomanic episodes, for most people the depression episodes are the more virulent aspect of the illness. Specifically, the depressive episodes are more numerous, last longer, and are more difficult to treat than the manias, and depression is the principal cause of the illness's increased mortality due to suicide. For people with early-onset depression, predictors of subsequent bipolarity include a family history, psychotic features, and reverse neurovegetative features. Initial episodes of depression are commonly misdiagnosed, which often delays initiation of appropriate therapy and increases the likelihood of treatment with antidepressants alone. Unfortunately, the correct diagnosis is often not made until there has been a treatment-emergent affective switch. There are no treatments specifically approved for bipolar disorder in youth and, among antidepressants, only fluoxetine has received approved. When bipolarity is suspected, treatment with mood stabilizers, both conventional (i.e., lithium, valproate, and carbamazapine) and more recently classified (lamotrigine) and atypical antipsychotics should be prioritized. When antidepressants are indicated in combination with mood stabilizers, first choice options include bupropion and the selective serotonin reuptake inhibitors. Studies of adults indicate that several forms of focused psychotherapy may improve longer term outcomes.

Risk of serotonin syndrome with concomitant administration of linezolid and serotonin agonists

Linezolid, an antimicrobial used to treat resistant gram-positive bacteria, can inhibit monoamine oxidase, an enzyme that metabolizes serotonin and other biogenic amines. Inhibition of this enzyme can predispose patients who are concomitantly taking serotonin agonists to serotonin syndrome. Because of the potential of linezolid to inhibit monoamine oxidase, premarketing studies were conducted with drugs such as selective serotonin reuptake inhibitors. No cases of serotonin syndrome were recorded. After linezolid was released to the United States market, several case reports of serotonin syndrome emerged. A literature search revealed 13 cases of serotonin syndrome occurring with the concomitant use of linezolid and drugs possessing serotonergic properties. To direct clinical management of this potential drug interaction, we reviewed reports of serotonin syndrome to determine relevant drug interactions with linezolid and serotonergic drugs and to characterize similarities and differences in the reported cases. Clinicians should obtain complete drug histories to identify patients at risk, strictly monitor drug therapy including concomitant drugs, and receive education about this potential drug interaction and the symptoms of serotonin syndrome.

Is there evidence for negative effects of antidepressants on suicidality in depressive patients? A systematic review

The role of antidepressants in suicide prevention is a major public health question given the high prevalence of both depression and depression-related suicidality. Therefore all available means should be utilised to clarify the influence of antidepressants on suicidality, especially in view of the ongoing intensive debate about possible suicidality-inducing effects of antidepressants that may outweigh their traditionally hypothesised beneficial effects. This paper gives a systematic and comprehensive review of the empirical data which might indicate that antidepressants have negative effects on suicidality. First, principal methodological issues related to this research question are discussed. Thereafter, the results of controlled trials and epidemiological and cohort studies are presented. Altogether, there seems to be only a small amount of evidence from different research approaches that antidepressants, not only serotonin reuptake inhibitors (SSRIs), might induce, aggravate or increase the risk of suicidal ideation and suicide attempts. As to suicide, there are no hints in this direction. TCAs have a higher risk of fatal outcome in overdose compared to SSRIs, which, in case of mono-intoxication, carry almost no risk of lethal consequences. The ongoing discussion about suicidality-inducing effects should not prevent physicians from prescribing SSRIs and other antidepressants to their patients if they are clinically indicated. However, they should take into account potential risks and manage them by good clinical practice.

Medication errors in mental healthcare: a systematic review

BACKGROUND

It has been estimated that medication error harms 1-2% of patients admitted to general hospitals. There has been no previous systematic review of the incidence, cause or type of medication error in mental healthcare services.

METHODS

A systematic literature search for studies that examined the incidence or cause of medication error in one or more stage(s) of the medication-management process in the setting of a community or hospital-based mental healthcare service was undertaken. The results in the context of the design of the study and the denominator used were examined.

RESULTS

All studies examined medication management processes, as opposed to outcomes. The reported rate of error was highest in studies that retrospectively examined drug charts, intermediate in those that relied on reporting by pharmacists to identify error and lowest in those that relied on organisational incident reporting systems. Only a few of the errors identified by the studies caused actual harm, mostly because they were detected and remedial action was taken before the patient received the drug. The focus of the research was on inpatients and prescriptions dispensed by mental health pharmacists.

CONCLUSION

Research about medication error in mental healthcare is limited. In particular, very little is known about the incidence of error in non-hospital settings or about the harm caused by it. Evidence is available from other sources that a substantial number of adverse drug events are caused by psychotropic drugs. Some of these are preventable and might probably, therefore, be due to medication error. On the basis of this and features of the organisation of mental healthcare that might predispose to medication error, priorities for future research are suggested.

Antidepressants and risk of upper gastrointestinal bleeding

Selective serotonin reuptake inhibitors (SSRIs) are nowadays the most widely used antidepressants in the world, mainly because they have a better adverse reaction profile and a higher safety margin in overdoses, when compared to other antidepressants. These drugs recently have been the target of important debates concerning safety issues, among them the possibility that they may increase the risk of bleeding. Over the 1990s, an increasing number of individual cases of bleeding disorders were reported in the literature and to the pharmacovigilance programmes which prompted several epidemiological and pharmacological studies. In this review we have examined all available data. The whole evidence supports the hypothesis that antidepressants with a relevant blockade action on serotonin reuptake mechanism increase the risk of bleeding. Such disorders may have different degrees of severity and may be located anywhere in the body. The epidemiological evidence is, however, more robust for upper gastrointestinal bleeding. It has been estimated that upper gastrointestinal bleeding may occur at a frequency ranging from 1 in 100 to 1 in 1,000 patient-years of exposure to high-affinity drugs (the SSRIs), with the very old patients being in the highest part of the range. The increased risk may be of particular relevance when the SSRIs are associated with NSAIDs as well as low-dose aspirin.

Intralipid outperforms sodium bicarbonate in a rabbit model of clomipramine toxicity

STUDY OBJECTIVE

Previous investigators have demonstrated amelioration of lipid-soluble drug toxidromes with infusion of lipid emulsions. Clomipramine is a lipid-soluble tricyclic antidepressant with significant cardiovascular depressant activity in human overdose. We compare resuscitation with Intralipid versus sodium bicarbonate in a rabbit model of clomipramine toxicity.

METHODS

Thirty sedated and mechanically ventilated New Zealand White rabbits were infused with clomipramine at 320 mg/kg per hour. At target mean arterial pressure of 50% initial mean arterial pressure, animals were rescued with 0.9% NaCl 12 mL/kg, 8.4% sodium bicarbonate 3 mL/kg, or 20% Intralipid 12 mL/kg. Pulse rate, mean arterial pressure, and QRS duration were sampled at 2.5-minute intervals to 15 minutes. In the second phase of the experiment, 8 sedated and mechanically ventilated rabbits were infused with clomipramine at 240 mg/kg per hour to a mean arterial pressure of 25 mm Hg. Animals received either 2 mL/kg 8.4% sodium bicarbonate or 8 mL/kg 20% Intralipid as rescue therapy. External cardiac compression and intravenous adrenaline were administered in the event of cardiovascular collapse.

RESULTS

Mean difference in mean arterial pressure between Intralipid- and saline solution-treated groups was 21.1 mm Hg (95% confidence interval [CI] 13.5 to 28.7 mm Hg) and 19.5 mm Hg (95% CI 10.5 to 28.9 mm Hg) at 5 and 15 minutes, respectively. Mean difference in mean arterial pressure between Intralipid- and bicarbonate-treated groups was 19.4 mm Hg (95% CI 18.8 to 27.0 mm Hg) and 11.5 mm Hg (95% CI 2.5 to 20.5 mm Hg) at 5 and 15 minutes. The rate of change in mean arterial pressure was greatest in the Intralipid-treated group at 3 minutes (6.2 mm Hg/min [95% CI 3.8 to 8.6 mm Hg/min] Intralipid versus -0.25 mm Hg/min [95% CI -1.9 to 1.4 mm Hg/min] saline solution) and 5 minutes (4.4 mm Hg/min [95% CI 3.0 to 5.9 mm Hg/min] Intralipid versus 0.06 mm Hg/min [95% CI -0.9 to 1.1 mm Hg/min] saline solution). In the second phase of the experiment spontaneous circulation was maintained in all Intralipid-treated rabbits (n=4). All animals in the bicarbonate-treated group developed pulseless electrical activity and proved refractory to resuscitation at 10 minutes (n=4, P=.023).

CONCLUSION

In this rabbit model, Intralipid infusion resulted in more rapid and complete reversal of clomipramine-induced hypotension compared with sodium bicarbonate. Additionally, Intralipid infusion prevented cardiovascular collapse in a model of severe clomipramine toxicity.

Citalopram and suicidality in adult major depression and anxiety disorders

The suicide-related data on citalopram from controlled clinical trials in depression and anxiety disorders were analysed. Safety data from placebo-controlled and relapse prevention citalopram trials in depression/major depressive disorder (MDD) and anxiety were searched for specific events relating to fatal suicide, non-fatal self-harm or suicidal thoughts. Efficacy data (item 10, suicidal thoughts, on the Montgomery-Asberg Depression Rating Scale [MADRS]) were also analysed. In the clinical trial database, the number of adverse events (fatal suicide, non-fatal self-harm or suicidal thoughts) was low, both during the first 2 weeks of treatment and during the full treatment period, with no statistically significant differences between citalopram and placebo. There was one fatal suicide during treatment (after 12 weeks of double-blind treatment in a relapse-prevention trial) for a patient treated with citalopram (incidence: 0.4%; rate: 0.010) and none on placebo. Citalopram was significantly more efficacious than placebo in lowering suicidal thoughts, based on efficacy rating (MADRS, item 10). There was no indication from this review of clinical trial data that citalopram may increase the risk of suicide in patients with MDD or anxiety. However, the patients in these clinical trials represent a selected group, as those patients with a significant risk of suicide were excluded at trial onset.

Selective serotonin reuptake inhibitors and suicidality in juveniles: review of the evidence and implications for clinical practice

This article reviews the existing evidence regarding whether selective serotonin reuptake inhibitors increase suicidal behaviors in children and examines the implications of the findings for clinical practice and research. When balanced against the fact that depression in the young is a serious, recurring condition that produces personal suffering and can lead to suicide, the overall weight of the evidence favors pharmacologic treatment over nontreatment in moderate to severe depression. Nevertheless, the need for careful clinical monitoring of suicidality and attention to behavioral activation, manic switching, and medication compliance or withdrawal are clearly warranted.

Dual serotonin and noradrenaline reuptake inhibitors: Focus on their differences

There are three non-tricyclic dual serotonin (5-HT) and noradrenaline (NA) reuptake inhibitors (SNRIs) currently used in human therapeutics for psychiatric disorders. These medications differ in their in vitro potency to inhibit 5-HT and NA reuptake with differential ratios of activity. Using in vivo studies carried out in laboratory animals, which better reflect human physiology than experiments using lysed tissue in a test tube, venlafaxine is about three times more potent on 5-HT than NA reuptake, duloxetine five times, and milnacipran is about twice more potent on NA than 5-HT reuptake. Sustained administration of SNRIs induces different adaptive effects on presynaptic 5-HT and NA receptors controlling the function of 5-HT and NA neurons, suggesting that they may differentially affect transmission of these two neuronal systems. In the treatment of depression, SNRIs appear to have similar effectiveness and when compared to selective 5-HT reuptake inhibitors, they generally exert a superior antidepressant effect. Taken together, these observations suggest that individual patients not responding to a SNRI may present a favourable response to another agent within that family. SNRIs have different pharmacokinetic properties and exert distinct effects on the activity of liver metabolic enzymes. These features of SNRIs can help clinicians tailor treatment to individual patients.

Heroin dependence in an English town: 33-year follow-up

BACKGROUND

There has been no long-term study of people addicted to injected heroin who have been treated without the prescribing of substitute opioids.

AIMS

To investigate the outcome for patients treated for injected heroin addiction 33 years after they were first seen, and 26 years after they were first followed up, in terms of sustained abstinence, continuing maintenance on methadone and deaths.

METHOD

Eighty-six people with heroin addiction first seen in in 1966-1967 in a small town in the south-east of England were located and their clinical state assessed using multiple sources, including personal interviews with a proportion of the cohort.

RESULTS

Forty-two per cent of the cohort had been abstinent for at least 10 years; 10% were taking methadone and were classified as addicted; and 22% had died. Eight percent of the cohort could not be located.

CONCLUSIONS

Results proved favourable in the above three parameters compared with other long-term studies.

SNRIs: their pharmacology, clinical efficacy, and tolerability in comparison with other classes of antidepressants

The class of serotonin and norepinephrine reuptake inhibitors (SNRIs) now comprises three medications: venlafaxine, milnacipran, and duloxetine. These drugs block the reuptake of both serotonin (5-HT) and norepinephrine with differing selectivity. Whereas milnacipran blocks 5-HT and norepinephrine reuptake with equal affinity, duloxetine has a 10-fold selectivity for 5-HT and venlafaxine a 30-fold selectivity for 5-HT. All three SNRIs are efficacious in treating a variety of anxiety disorders. There is no evidence for major differences between SNRIs and SSRIs in their efficacy in treating anxiety disorders. In contrast to SSRIs, which are generally ineffective in treating chronic pain, all three SNRIs seem to be helpful in relieving chronic pain associated with and independent of depression. Tolerability of an SNRI at therapeutic doses varies within the class. Although no direct comparative data are available, venlafaxine seems to be the least well-tolerated, combining serotonergic adverse effects (nausea, sexual dysfunction, withdrawal problems) with a dose-dependent cardiovascular phenomenon, principally hypertension. Duloxetine and milnacipran appear better tolerated and essentially devoid of cardiovascular toxicity.

Bipolar depression: issues in diagnosis and treatment

Although bipolar affective disorder is defined by the history of manic or hypomanic episodes, depression is arguably a more important facet of the illness. Depressive episodes, on average, are more numerous and last longer than manic or hypomanic episodes, and most suicides occur during these periods. Misdiagnosis of major depressive disorder delays initiation of appropriate therapy, further worsening prognosis. Distinguishing features of bipolar depression include earlier age of onset, a family history of bipolar disorder, presence of psychotic or reverse neurovegetative features, and antidepressant-induced switching. Bipolar I depressions should initially be treated with a mood stabilizer (carbamazapine, divalproex, lamotrigine, lithium, or an atypical antipsychotic); antidepressant monotherapy is contraindicated. More severe or "breakthrough" episodes often require a concomitant antidepressant, such as bupropion or a selective serotonin reuptake inhibitor (SSRI). The first treatment specifically approved for bipolar depression is a combination of the SSRI fluoxetine and the atypical antipsychotic olanzapine. For refractory depressive episodes, venlafaxine, the monoamine oxidase inhibitor tranylcypromine, and ECT are most widely recommended. The optimal duration of maintenance antidepressant therapy has not been established empirically and, until better evidence-based guidelines are established, should be determined on a case-by-case basis.

Newer antidepressants: evaluation of fatal toxicity index and interaction with alcohol based on Finnish postmortem data

Finnish postmortem toxicology data from 1995 to 2002 was analyzed to obtain improved estimates of fatal toxicity indices for the newer antidepressants and to evaluate their interaction with alcohol. Altogether 284 fatal poisonings were attributed to 12 different newer antidepressants. Venlafaxine, mianserin, moclobemide, and mirtazapine were responsible for significantly more deaths than expected from their sales. Their fatal toxicity indices were higher than those of selective serotonin reuptake inhibitors (SSRIs) but lower than those of tricyclic antidepressants. In fatal poisonings involving alcohol in combination with venlafaxine, mianserin, moclobemide, or mirtazapine, the median blood alcohol concentration (BAC) ranged from 2.35 to 2.7 mg/g, whereas in those involving alcohol in combination with citalopram or fluoxetine the median BAC was 2.9 and 3.4 mg/g, respectively. The BAC was significantly lower in venlafaxine-related deaths than in those involving fluoxetine or citalopram. We conclude that among the newer antidepressants differences are present both in toxicity and in interaction potential with alcohol. The SSRIs appear to present a low risk of fatal poisoning when taken alone or in combination with alcohol, whereas venlafaxine is associated with an elevated risk.

Prevalence of risk factors for suicide in patients prescribed venlafaxine, fluoxetine, and citalopram

PURPOSE

Three recent observational studies reported that the risk of fatal overdose is greater with venlafaxine than SSRI use. It is not clear whether patient factors could account for this finding. We evaluated whether risk factors for suicide are more prevalent among patients prescribed venlafaxine than patients prescribed fluoxetine or citalopram.

METHODS

Using data from the UK General Practice Research Database (GPRD), we identified patients who were first prescribed any of the three drugs between January 1995 and April 2002. We ascertained risk factors for suicide documented in the 1 year before that first prescription. Separate analyses compared venlafaxine (N = 27 096) and fluoxetine (N = 134 996) cohorts, and venlafaxine and citalopram (N = 52 035) cohorts.

RESULTS

Previous suicidal behaviors were documented for 1.0% of the venlafaxine cohort compared to 0.4% of the fluoxetine cohort (OR 2.8, 95%CI: 2.4, 3.2) and 0.4% citalopram cohorts (OR 2.4, 95%CI: 2.0, 2.9). 72.5% of venlafaxine patients had been prescribed at least one other antidepressant compared to 27.6% of fluoxetine (OR 6.9, 95%CI: 6.7, 7.1) and 39.5% of citalopram (OR 4.0, 95%CI: 3.9, 4.2) patients. Venlafaxine patients were also four to six times as likely to have been previously hospitalized for depression.

CONCLUSION

In the UK, venlafaxine has been selectively prescribed to a patient population with a higher burden of suicide risk factors than patients prescribed fluoxetine and citalopram. Unless baseline population differences are accounted for, observational studies that compare the risk of suicide in patients receiving these agents may produce biased results.

Tricyclic Antidepressant Poisoning

All tricyclic drugs are potentially able to cause the main acute CNS toxic syndromes of coma and convulsions. Dosulepin (dothiepin) seems more likely to cause convulsions than other drugs in this class, and amitriptyline also appears a more toxic tricyclic agent. Coma is the most useful sign indicative of toxic risk and appears to predict severe toxic complications (fits and arrhythmias) more reliably than ECG changes. Prophylactic therapy against convulsions has not been shown to be effective. Use of an anticholinesterase (physostigmine) is not recommended for management of coma. There is no good evidence base to support a particular anticonvulsant.

Results of a naturalistic longitudinal study of benzodiazepine and SSRI use in the treatment of generalized anxiety disorder and social phobia

The past decade has brought major new developments in the psychopharmacologic management of generalized anxiety disorder and social phobia. We examined medication-prescribing patterns for the treatment of these anxiety disorders for 12 years to assess changes in patients' anti-anxiety psychotropic medication usage during that period of evolving practice guidelines. We examined psychotropic medication use in 305 patients with generalized anxiety disorder and 232 with social phobia enrolled in the Harvard/Brown Anxiety Disorders Research Project (HARP), a prospective, longitudinal study of anxiety disorders. Psychotropic treatment patterns seem to have remained relatively stable over 12 years with benzodiazepines the medications most commonly used for both generalized anxiety disorder and social phobia. Comparatively, selective serotonin reuptake inhibitor (SSRI) and venlafaxine usage as stand-alone medications for these disorders remained low throughout the follow-up period. At the 12-year follow-up, 24% of patients with generalized anxiety disorder and 30% of patients with social phobia were utilizing neither an SSRI/selective norepinephrine reuptake inhibitor (SNRI) nor a benzodiazepine. Treatment recommendations for use of SSRIs and venlafaxine in the management of generalized anxiety disorder and social phobia initially promulgated in 1998 had a modest impact on changes in psychopharmacologic practice 4-5 years later. Difficulties in the implementation of treatment guidelines are discussed.