Neuron-specific deletion of VEGF or its receptor Flk-1 occludes the antidepressant-like effects of desipramine and fluoxetine in mice

Vascular endothelial growth factor (VEGF) signaling is known to be involved in the antidepressant-like effects of conventional antidepressants, such as desipramine (DMI), a tricyclic antidepressant, and fluoxetine (FLX), a selective serotonin reuptake inhibitor; however, the precise role of neuronal VEGF signaling in mediating these effects remains unclear. Using mice with excitatory neuron-specific deletion of VEGF and its receptor, fetal liver kinase 1 (Flk-1) in the forebrain, we examined the effects of forebrain excitatory neuron-specific deletion of VEGF or Flk-1 on the antidepressant-like effects of repeated DMI and chronic FLX administration in the forced swim test (FST). Repeated intraperitoneal (i.p.) injections of DMI (10, 10, and 20 mg/kg at 24, 4, and 1 h before the FST, respectively) significantly decreased immobility in control mice; however, this effect was completely blocked in mice with neuron-specific VEGF or Flk-1 deletion. Although chronic treatment with FLX (18 mg/kg/day, i.p.) did not impact immobility in control mice 1 day after the 22nd injection, immobility was significantly reduced 1 day after the preswim and the 23rd FLX injection. However, in mice with neuron-specific Flk-1 deletion, chronic FLX treatment significantly increased immobility in the preswim and failed to produce antidepressant-like effects. Collectively, these findings indicate that neuronal VEGF-Flk-1 signaling contributes to the antidepressant-like actions of conventional antidepressants.

Novel hyperpigmentation pathophysiology following a prolonged course of imipramine therapy

Imipramine is a tricyclic antidepressant typically reserved for patients with treatment-resistant mood disorders. A rare side effect of long-term use of imipramine is a slowly progressive melanin-associated, slate gray-blue hyperpigmentation of the skin in a photo-distributed pattern. We report a case of imipramine-induced hyperpigmentation developing 50 years after initiating imipramine therapy, whose lesions were essentially devoid of melanin on histopathological exam. This differs from all other reported cases of imipramine-induced hyperpigmentation in two notable respects. First, the time between initiating imipramine therapy and the onset of pigmentation changes was nearly 30 years longer than prior case reports. Second, the lack of melanin in our samples suggests a divergence from the hypothesized melanin-imipramine complex mechanism of hyperpigmentation. Instead, we propose a novel pathogenesis of imipramine-induced hyperpigmentation that is unrelated to melanin.

False-positive results for pheochromocytoma associated with norepinephrine reuptake blockade

Measurements of plasma metanephrines and methoxytyramine provide a sensitive test for diagnosis of pheochromocytoma/paraganglioma. False-positive results remain a problem, particularly in patients taking norepinephrine reuptake-blocking drugs. Therefore, in this retrospective observational study, we measured plasma metanephrines and methoxytyramine in 61 patients taking norepinephrine reuptake blockers (tricyclic antidepressants or serotonin-norepinephrine reuptake inhibitors) and 17 others taking selective serotonin reuptake inhibitors, all without pheochromocytoma/paraganglioma. We highlight a singular case with strongly elevated plasma normetanephrine and methoxytyramine concentrations associated with norepinephrine reuptake blockade. Data were compared to results from 252 and 1804 respective patients with and without tumors. Plasma normetanephrine was 40% higher (P < 0.0001) in patients on norepinephrine reuptake blockers and methoxytyramine was 127% higher (P = 0.0062) in patients taking tricyclic antidepressants compared to patients not taking uptake blockers and without tumors. The corresponding false-positive rates rose (P < 0.0001) from 4.8% to 23.0% for normetanephrine and from 0.9% to 28.6% for methoxytyramine. Selective serotonin reuptake inhibitors did not increase plasma concentrations of metabolites. In the highlighted case, plasma normetanephrine and methoxytyramine were elevated more than six times above upper reference limits. A pheochromocytoma/paraganglioma, however, was excluded by functional imaging. All biochemical test results normalized after discontinuation of norepinephrine reuptake blockers. These findings clarify that norepinephrine reuptake blockers usually result in mild elevations of normetanephrine and methoxytyramine that, nevertheless, significantly increase the number of false-positive results. There can, however, be exceptions where increases in normetanephrine and methoxytyramine reach pathological levels. Such exceptions may reflect failure of centrally mediated sympathoinhibition that normally occurs with the norepinephrine reuptake blockade.

Duloxetine and Amitriptyline Reduce Neuropathic Pain by Inhibiting Primary Sensory Input to Spinal Dorsal Horn Neurons via α1- and α2-Adrenergic Receptors

Antidepressants, such as duloxetine and amitriptyline, are effective for treating patients with chronic neuropathic pain. Inhibiting norepinephrine and serotonin transporters at presynaptic terminals raises extracellular concentrations of norepinephrine. The α1- and α2-adrenergic receptor agonists inhibit glutamatergic input from primary afferent nerves to the spinal dorsal horn. However, the contribution of spinal α1- and α2-adrenergic receptors to the analgesic effect of antidepressants and associated synaptic plasticity remains uncertain. In this study, we showed that systemic administration of duloxetine or amitriptyline acutely reduced tactile allodynia and mechanical and thermal hyperalgesia caused by spinal nerve ligation in rats. In contrast, duloxetine or amitriptyline had no effect on nociception in sham rats. Blocking α1-adrenergic receptors with WB-4101 or α2-adrenergic receptors with yohimbine at the spinal level diminished the analgesic effect of systemically administered duloxetine and amitriptyline. Furthermore, intrathecal injection of duloxetine or amitriptyline similarly attenuated pain hypersensitivity in nerve-injured rats; the analgesic effect was abolished by intrathecal pretreatment with both WB-4101 and yohimbine. In addition, whole-cell patch-clamp recordings in spinal cord slices showed that duloxetine or amitriptyline rapidly inhibited dorsal root-evoked excitatory postsynaptic currents in dorsal horn neurons in nerve-injured rats but had no such effect in sham rats. The inhibitory effect of duloxetine and amitriptyline was abolished by the WB-4101 and yohimbine combination. Therefore, antidepressants attenuate neuropathic pain predominantly by inhibiting primary afferent input to the spinal cord via activating both α1- and α2-adrenergic receptors. This information helps the design of new strategies to improve the treatment of neuropathic pain.

Management of treatment-resistant nocturnal enuresis

Nocturnal enuresis is defined as intermittent urinary incontinence during sleep in children 5 years of age and older, occurring at least once a month for at least 3 months. In Japan, pediatricians who do not specialize in nocturnal enuresis have become more proactive in treating the condition since 2016, when the guidelines for treating it were revised for the first time in 12 years. For monosymptomatic nocturnal enuresis, the first step is lifestyle guidance, with a focus on the restriction of fluid intake at night; however, if lifestyle guidance does not decrease the frequency of nocturnal enuresis, aggressive treatment should be added. The first choice of aggressive treatment is oral desmopressin, an antidiuretic hormone preparation, or alarm therapy. However, there remain patients whose wet nights do not decrease with oral desmopressin or alarm therapy. In such cases, it is necessary to reconfirm the method of desmopressin administration and check for factors that may decrease the efficacy of desmopressin. If alarm therapy does not increase the number of dry nights, it is possible that the patient is fundamentally unsuitable for alarm therapy. If dry nights do not increase with oral desmopressin or alarm therapy, the next treatment strategy should be considered immediately to keep the patient motivated for treatment.

Comparison of Clinical Manifestations of Patients Poisoned with Tricyclic Antidepressants Alone or with Benzodiazepine Intoxication According to the Dose of Benzodiazepines

Objective

Tricyclic antidepressants poisoning (TCA) is associated with cardiovascular complications, electrocardiographic abnormalities, and central nervous system toxicity. This study aimed to compare the clinical manifestations of poisoned patients with tricyclic antidepressants alone or with benzodiazepine (BZD) intoxication according to the dose of BZDs.

Methods

In this case-control study, 120 patients with TCA poisoning were divided into four groups: the first group of TCA poisoning alone, the second group of TCA and BZD poisoning of <7.75 mg, the third group of TCA and B poisoning of 7.75 to 80 mg, and the fourth group of more than 80 mg of TCA and BZD poisoning. Patients' demographic, clinical, and cardiac information was extracted from their records at admission and 6 h after admission.

Findings

Cardiac complications 6 h after referral and total cardiac complications between TCA and TCA low-dose BZD groups were significantly reduced in the low-dose BZD poisoning group. Comparison of TCA and TCA groups with a moderate dose of BZD showed a significant reduction in time six and total cardiac complications. However, due to the significant difference in TCA values between the two groups, the results are not significant. Comparing the two groups of TCA and TCA with a high dose of BZD, both 6-hour cardiac complications and total cardiac complications in the high-dose BZD group, it was significantly reduced. However, the loss of consciousness was also considerably greater in the high-dose BZD group than in the TCA group.

Conclusion

Concomitant BZDs with TCA can reduce cardiovascular complications from TCA poisoning. However, with high doses of BZDs, there is a greater loss of consciousness.

Tricyclic Antidepressant Overdose Manikin Simulation in Student Pharmacists

Background: Pharmacists must be knowledgeable of medication use within the scope of both typical dosing and atypical dosing. In the United States, antidepressants are the fourth most common substance in overdose situations and are ranked first for serious exposures per year. Objective: The purpose of this study is to design, implement, and assess the efficacy of an antidepressant overdose simulation using a high-fidelity manikin. Methods: This was a single-center, prospective, observational, cross-sectional study of third-year student pharmacists in spring 2021. This study was determined to be exempt by the institutional review board. Students who did not participate in the manikin simulation or complete both the pre- and postsimulation surveys were excluded. Student pharmacists were expected to identify the type of overdose, identify probable offending agent, and evaluate the hemodynamic status. Primary objectives compared student pharmacist knowledge, confidence in recognizing overdose, and confidence in managing overdose pre- and post-antidepressant overdose manikin simulation. Results: Twenty-three students completed both surveys and participated in the simulation. The knowledge total score was 2.1 ± 1.3 in the presimulation and 2.9 ± 0.9 in the postsimulation (P < 0.001). The recognition confidence was 2.0 ± 1.3 in the presimulation and 3.7 ± 0.7 in the postsimulation (P < 0.001). The management confidence was 1.8 ± 1.0 in the presimulation and 3.5 ± 0.5 in the postsimulation (P < 0.001). Limitations in this study were small sample size, lack of rubric, and a case prompt. Conclusion: The outcomes were statistically significant postsimulation. Manikin simulations may have a larger impact on a pharmacy curriculum.

Inhibition of TRPC4 channel activity in colonic myocytes by tricyclic antidepressants disrupts colonic motility causing constipation

Tricyclic antidepressants (TCAs) have been used to treat depression and were recently approved for treating irritable bowel syndrome (IBS) patients with severe or refractory IBS symptoms. However, the molecular mechanism of TCA action in the gastrointestinal (GI) tract remains poorly understood. Transient receptor potential channel canonical type 4 (TRPC4), which is a Ca²⁺‐permeable nonselective cation channel, is a critical regulator of GI excitability. Herein, we investigated whether TCA modulates TRPC4 channel activity and which mechanism in colonic myocytes consequently causes constipation. To prove the clinical benefit in patients with diarrhoea caused by TCA treatment, we performed mechanical tension recording of repetitive motor pattern (RMP) in segment, electric field stimulation (EFS)‐induced and spontaneous contractions in isolated muscle strips. From these recordings, we observed that all TCA compounds significantly inhibited contractions of colonic motility in human. To determine the contribution of TRPC4 to colonic motility, we measured the electrical activity of heterologous or endogenous TRPC4 by TCAs using the patch clamp technique in HEK293 cells and murine colonic myocytes. In TRPC4‐overexpressed HEK cells, we observed TCA‐evoked direct inhibition of TRPC4. Compared with TRPC4‐knockout mice, we identified that muscarinic cationic current (mI_cat) was suppressed through TRPC4 inhibition by TCA in isolated murine colonic myocytes. Collectively, we suggest that TCA action is responsible for the inhibition of TRPC4 channels in colonic myocytes, ultimately causing constipation. These findings provide clinical insights into abnormal intestinal motility and medical interventions aimed at IBS therapy.

Effectiveness of a clinical decision-support tool on adherence to prescribing and practice guidelines of high-risk antidepressant medications in geriatric patients

Introduction

TCAs and paroxetine, a SSRI, are associated with safety risks in geriatric patients because of anticholinergic properties. The purpose of this project was to evaluate the impact of a clinical decision-support tool (CDST) on adherence with medication prescribing and practice guidance to enhance patient safety.

Methods

Mental health clinical pharmacy specialists and clinical pharmacy leadership led a multidisciplinary creation and integration of a CDST within a Veterans Health Administration EHR. The CDST focused on the following elements when prescribing TCAs and paroxetine in geriatric patients: clinical justification for initiation of the medication, provision of patient/caregiver education specific to the medication prescribed, evaluation of comprehension of education provided, medication reconciliation, and follow-up completed within 30 days of medication initiation. Following activation of the CDST in the EHR, measures were evaluated before intervention and after intervention.

Results

After intervention, an increase was observed in the primary outcome of the proportion of patients having documentation of all of the following: clinical justification for medication initiation, provision of patient/caregiver education, evaluation of comprehension of education provided, medication reconciliation, and follow-up completed within 30 days of medication initiation (P = .01). Individual proportions of patients with documented medication reconciliation and follow-up completed within 30 days significantly increased. All other secondary outcomes numerically increased but did not reach statistical significance.

Discussion

Improvement was seen in adherence with prescribing and practice guidance following the implementation of the CDST. This suggests the beneficial role of CDSTs within the EHR to optimize patient safety.

Veno-arterial extracorporeal membrane oxygenation and targeted temperature management in tricyclic antidepressant-induced cardiac arrest: A case report and literature review

RATIONALE

Cardiotoxicity is a common cause of death in tricyclic antidepressant (TCA) intoxication. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is effective in critically ill poisoned patients who do not respond to conventional therapies, and targeted temperature management (TTM) is associated with improved neurological outcomes and mortality in comatose out-of-hospital cardiac arrest survivors. However, few reports have documented cases of TCA intoxication that required intensive care, including VA-ECMO or TTM.

PATIENT CONCERNS

A 19-year-old Japanese man with a history of depression was brought to our hospital because he was in a comatose state with a generalized seizure. Before admission, he had taken an unknown amount of amitriptyline.

DIAGNOSIS

After intubation, the electrocardiogram (ECG) displayed a wide QRS complex tachycardia, and the patient suffered from cardiovascular instability despite intravenous bolus of sodium bicarbonate. At 200 minutes after ingestion, he experienced a TCA-induced cardiac arrest.

INTERVENTIONS

We initiated VA-ECMO 240 minutes after ingestion. The hemodynamic status stabilized, and the ECG abnormality improved gradually. In addition, we initiated targeted temperature management (TTM) with a target temperature of 34°C.

OUTCOMES

Twenty seven hours after starting the pump, the patient was weaned off the VA-ECMO. After completing the TTM, his mental status improved, and he was extubated on day 5. He was discharged on day 15 without neurological impairment, and the post-discharge course was uneventful.

LESSONS

First, VA-ECMO is effective in patients with TCA-induced cardiac arrest. Second, routine ECG screening during VA-ECMO support is useful for assessing the timing to wean off the VA-ECMO, as well as the degree of cardiotoxicity. Third, TTM is safe in comatose survivors of cardiac arrest caused by severe TCA intoxication.

Classics in Chemical Neuroscience: Amitriptyline

Amitriptyline was the second tricyclic antidepressant to appear on the market for major depressive disorder under the brand name Elavil in 1961. Since its emergence, amitriptyline has been an effective therapeutic in various disease states and disorders but has also been a concerning source of cardiotoxicity. Amitriptyline inhibits serotonin and norepinephrine reuptake as well as produces off-target activity at histaminergic, muscarinic, and various other receptors. Its role as a modulator of monoamines helped further establish the monoamine theory to understand various mood disorders, paving the way for the now more common selective serotonin/norepinephrine reuptake inhibitors. In this review, we will discuss amitriptyline's synthesis, manufacturing information, drug metabolism, pharmacology, adverse effects, and its history and importance in therapy to present amitriptyline as a true classic in chemical neuroscience.

Fetal teratogenicity in a rhesus macaque (Macaca mulatta): Association with the chronic maternal treatment of amitriptyline

Amitriptyline is a tricyclic antidepressant commonly prescribed in humans for pain and sleep disorders and in non-human primates for self-injurious behaviors. Here, we report a clinical case on the teratogenic effect of maternal-fetal amitriptyline exposure.

Elucidation of Degradation Behavior of Tricyclic Antidepressant Amoxapine in Artificial Gastric Juice

The degradation behavior of eight tricyclic antidepressants (TCAs; amitriptyline, amoxapine (AMX), imipramine, clomipramine, desipramine, doxepin, dothiepin, and nortriptyline) in artificial gastric juice was investigated to estimate their pharmacokinetics in the stomach. As a result, among the eight TCAs, only AMX was degraded in artificial gastric juice. The degradation was a pseudo first-order reaction; activation energy (Ea) was 88.70 kJ/mol and activation entropy (ΔS) was -80.73 J/K·mol. On the other hand, the recovery experiment revealed that the degradation product did not revert to AMX and accordingly, this reaction was considered to be irreversible. In the AMX degradation experiment, peaks considered to be degradation products A (I) and B (II) were detected at retention times of around 3 min and 30 min in LC/UV measurements, respectively. Structural analysis revealed that compound (I) was [2-(2-aminophenoxy)-5-chlorophenyl]-piperazin-1-yl-methanone, a new compound, and compound (II) was 2-chlorodibenzo[b,f][1,4]oxazepin-11(10H)-one. As for the degradation behavior, it was estimated that AMX was degraded into (II) via (I), i.e., (II) was the final product. The results are expected to be useful in clinical chemistry and forensic science, including the estimation of drugs to be used at the time of judicial dissection and suspected drug addiction.

Role of GABAA Receptors in the Mechanism of In Vivo Psychotropic Activity of Amitriptyline in Rats

Standard water-reinforced drug discrimination model was employed to train Wistar rats to discriminate the intraperitoneal injections of tricyclic antidepressant amitriptyline (5.4 mg/kg) and physiological saline. To examine the role of GABA_A receptors in psychotropic action of amitriptyline, the substitution tests were performed with muscimol (0.1-1.0 mg/kg) and pregnenolone (30-50 mg/kg). Similar tests were carried out with amitriptyline interoceptive antagonists bicuculline (1 mg/kg), flumazenil (15 mg/kg), finasteride (5 mg/kg), and indomethacin (7.5 mg/kg). The study showed that interoceptive effects of amitriptyline depend on functional activity of GABA_A receptors but not on the neurosteroid site of GABA_A receptor complex.

Trends in Antidepressant Use and Expenditure in Six Major Cities in China From 2013 to 2018

The objective of this study was to investigate the current status and trends in antidepressant use and expenditure in China from 2013 to 2018. The study had a retrospective design based on prescribing data on antidepressant drugs, which was sourced from the Hospital Prescription Analysis Cooperative Project. The trends in hospital visits and corresponding expenditure on antidepressant drugs were examined. Subgroup analyses were carried out by sex, age, and drug class. A total of 1,795,230 outpatient prescriptions were collected from 79 hospitals in six major cities in China. Hospital visits with antidepressant prescriptions rose significantly from 244,626 in 2013 to 348,718 in 2018, reflecting a 42.6% increase (P < 0.05). The antidepressant expenditure also rose, increasing from 48.0 million Chinese yuan in 2013 to 64.8 million Chinese yuan in 2018. There were approximately 1.6 times more antidepressant prescriptions written for women than for men. The most frequent age category for antidepressant prescriptions was 45-64 years. The most commonly prescribed antidepressants were selective serotonin reuptake inhibitors (N06AB) and other antidepressants (N06AX), whereas tricyclic antidepressants (N06AA) accounted for only a small part of the total antidepressant prescriptions. Flupentixol/melitracen and escitalopram were the most frequently prescribed antidepressants. Antidepressant prescribing rates continue to increase in China, although the prescribing patterns have changed over the past few years. The wide use of expensive antidepressants and those with weak clinical evidence raises concerns regarding the rational use of antidepressants. This study provides a basis for future stewardship by the government and medical institutions.

Pharmacologic therapies for the management of non-neurogenic urinary incontinence in children

Introduction: Non-neurogenic urinary incontinence in children is a common condition that affects the quality of life for both patients and parents. Symptoms may occur in the daytime, nighttime, or both and may be the result of structural and functional anomalies. Evaluation and management of associated co-morbidities, such as constipation is critical to management. Behavioral therapy is a fist line therapy in most cases of non-neurogenic urinary incontinence and pharmacologic therapy a second-line therapy.Areas covered: In this review, the authors cover the pharmacologic agents, FDA approved and commonly used non-FDA approved, available for the treatment of four non-structural etiologies of non-neurogenic urinary incontinence in children. These include nocturnal enuresis, overactive bladder, giggle incontinence, and dysfunctional voiding.Expert opinion: Non-neurogenic causes of urinary incontinence in children represent a complicated medical condition that requires both pharmacologic and non-pharmacologic management. Limited FDA-approved therapies as well as suboptimal results with approved therapies due to a lack in the understanding of the underlying pathophysiology and patient selection may lead to the use of alternative non-FDA approved therapies.

Pharmacotherapeutic outcomes in atypical odontalgia: determinants of pain relief

Objectives

There has been considerable research which has focused on clarifying the origin of pain in patients with atypical odontalgia (AO), also known as “idiopathic toothache”, and on identifying effective treatment, but there has been limited success so far. In this study, we assessed the outcomes of treatment and attempted to identify factors that could account for pain remission in patients with AO.

Patients and methods

Data for 165 patients diagnosed with AO from June 2015 to August 2017 were retrospectively reviewed. The patients’ sex, age, duration of pain, and psychiatric history were collected, along with information on pain intensity, depressive status, and catastrophizing scores. Responses at 4 and 16 weeks from the start of treatment were observed. The associations between potentially associated factors and outcome were investigated using Bayesian model averaging.

Results

A 30% reduction in pain was reported by 38 patients (46.3%) at 4 weeks and by 54 patients (65.9%) at 16 weeks. The pain intensity decreased as the depression and catastrophizing score improved; all of the changes were statistically significant (P<0.001). Four elements, that is, patient sex, depression score at baseline, pain score at 4 weeks, and change in the catastrophizing score, explained 52.5% of the variation in final outcome between individual patients.

Conclusion

Our findings confirm the efficacy of tricyclic antidepressants (TCAs) as a treatment for AO and indicate that other medications, especially aripiprazole used in combination with a TCA, may be useful. A considerable number of patients, especially women, those with lower levels of depression at baseline, and those who responded to 4 weeks of treatment, achieved pain relief.

Determination of tricyclic antidepressants in human urine samples by the three-step sample pretreatment followed by HPLC-UV analysis: an efficient analytical method for further pharmacokinetic and forensic studies

In this work, an efficient sample pretreatment method has been developed by combining salt induced-homogenous liquid-liquid extraction, dispersive solid phase extraction, and dispersive liquid-liquid microextraction based on the solidification of floating organic droplet for the extraction of some widely used tricyclic antidepressant (TCA) drugs (nortriptyline, amitriptyline, desipramine, clomipramine, and imipramine) in human urine samples before their determination by high performance liquid chromatography-ultraviolet detection. In brief, the target analytes are first isolated from urine samples into acetonitrile (ACN) separated by adding a salt. Then the obtained ACN phase is treated with a mixture of appropriate sorbents to remove interferences. Afterward, the purified ACN is mixed with menthol as an extractant and rapidly injected into alkaline HPLC-grade water as a preconcentration step. Next, the obtained solution is placed in an ice bath and menthol collects on top of the solution after solidification. The solidified drop is then withdrawn and injected into separation system after dissolving in 10 µL ACN. Under the optimum experimental conditions, extraction recoveries and enrichment factors of the selected drugs ranged from 69-84 % and 345-420, respectively. The limits of detection and quantification were obtained at the ranges of 0.22-0.31, and 0.71-1.1 µg L^-1, respectively. The relative standard deviations of the proposed method were ≤ 6 % for intra- (n=6) and inter-day (n=4) precisions at a concentration of 10 µg L^-1 (each drug). Finally, the suggested approach was applied to determine of TCA drugs in different patients' urine samples. The method could be applied in further TCAs pharmacokinetic and forensic studies.

Tricyclic antidepressant use and the risk of fibrosis progression in hepatitis C-infected persons: Results from ERCHIVES

Recent preclinical studies have suggested an antifibrotic role for tricyclic antidepressants (TCA). Using the Electronically Retrieved Cohort of hepatitis C virus (HCV) Infected Veterans, we aimed to evaluate the impact of TCA use on fibrosis progression and development of hepatocellular carcinoma (HCC) among HCV-infected persons. Subjects were categorized according to use of TCAs, selective serotonin reuptake inhibitors (SSRI) or no antidepressants. TCAs or selective serotonin uptake inhibitors use was defined according to cumulative defined daily dose (cDDD), and categories were mutually exclusive. Subjects with HIV coinfection, hepatitis B surface antigen (HbsAg) positivity, cirrhosis or HCC at baseline were excluded. Outcomes were liver fibrosis progression measured by APRI scores and incident HCC. We utilized Cox proportional hazards regression to determine predictors of cirrhosis, defined as APRI > 2, and incident hepatocellular carcinoma (iHCC). Among 128 201 eligible HCV+ persons, 4% received TCAs, 43% received selective serotonin uptake inhibitors, and 53% received no antidepressants. Fewer TCAs users had drug abuse (34% and 43%) and alcohol abuse (32% vs 42%) compared to selective serotonin uptake inhibitor users. After adjusting for age, baseline APRI score, diabetes, hypertension, alcohol use, drug abuse and HCV RNA levels, TCAs use was associated with decreased risk of cirrhosis (hazard ratio [HR] = 0.77, 95% CI = 0.60, 0.99) and delayed time to development of cirrhosis, but not with decreased iHCC. In conclusion among a large cohort of HCV-positive Veterans, TCAs use was associated with decreased fibrosis progression and lower risk of developing cirrhosis. These data provide supportive evidence for the beneficial effects of TCAs on progression of liver fibrosis in patients with chronic HCV infection.

Efficacy and safety of nortriptyline in functional dyspepsia in Asians: A randomized double-blind placebo-controlled trial

BACKGROUND AND AIM

Current treatments of functional dyspepsia (FD) are unsatisfied. Tricyclic antidepressants alter visceral hypersensitivity and brain-gut interaction. We assessed the efficacy and safety of nortriptyline in patients with FD.

METHODS

Patients diagnosed with FD according to Rome III criteria who failed to respond to proton pump inhibitor and prokinetic treatment were randomly assigned to either once daily 10-mg nortriptyline or placebo. The primary endpoint was the rate of responders defined as > 50% reduction in dyspepsia symptom score after 8 weeks of treatment. The secondary endpoints were improvement in quality of life as assessed by 36-Item Short Form Health Survey score and safety.

RESULTS

Sixty-one patients (nortriptyline 28 and placebo 33) were enrolled. Dyspepsia symptom score and duration of symptoms were balanced at entry between both groups. Eight and seven patients in nortriptyline and placebo groups were lost to follow up. Seven patients withdrew due to mild adverse events (nortriptyline 1 and placebo 6). Overall, 19 with nortriptyline and 20 with placebo completed the study. Patients receiving nortriptyline did not achieve higher response rate than those in placebo in both intention-to-treat (53.6% vs 57.6%, P = 0.75) and per-protocol (76.5% vs 73.7%, P = 1.00) analyses. Nortriptyline did not provide improvement in quality of life. The mean difference was 3.8 (P = 0.36) and 0.88 (P = 0.86) by intention-to-treat and 2.9 (P = 0.57) and 3.5 (P = 0.57) by per-protocol analyses in physical and mental component, respectively. All adverse events were minor and similar in both groups.

CONCLUSION

Nortriptyline was not superior to placebo in management of patients with FD.

Noradrenaline plays a critical role in the switch to a manic episode and treatment of a depressive episode

Although antidepressants may increase the risk of switching to mania in bipolar disorder (BD), clinicians have been using antidepressants to treat patients with bipolar depression. Appropriate treatments for bipolar depression remain controversial. In BD, antidepressants comprise a double-edged sword in terms of their efficacy in treating depression and the increased risk of switching. This review presents an important table outlining the benefit in terms of depression improvement and the risk of switching in the clinical setting. It also proposes strategies based on the characteristics of antidepressants such as their pharmacology, specifically the equilibrium dissociation constant (K_D) of the noradrenaline transporter. This table will be useful for clinicians while considering benefit and risk. Antidepressants augmenting noradrenaline may be effective in bipolar depression. However, it is easily presumed that such antidepressants may also have a risk of switching to mania. Therefore, antidepressants augmenting noradrenaline will be the recommended treatment in combination with an antimanic agent, or they may be used for short-term treatment and early discontinuation. The corresponding medical treatment guidelines probably need to be reevaluated and updated based on biological backgrounds. From previous studies, we understand that the stability of noradrenaline levels is important for BD amelioration, based on the pathophysiology of the disorder. It is hoped that researchers will reevaluate BD by conducting studies involving noradrenaline.

Accelerated antidepressant response to lithium augmentation of imipramine

BACKGROUND

Treatment of depressive episode often poses a challenge. Although there are numerous medicines available for its treatment but they all have a lag period of 2-3 weeks before they start showing their result.

AIM

The aim of the present study was to test the hypothesis that an initial lithium-tricyclic antidepressant (TCA) combination has a quicker and better antidepressant effect than standard TCA treatment in unipolar depression.

MATERIALS AND METHODS

Twenty unipolar depressed inpatients under lithium-TCA treatment were compared with twenty patients with similar diagnosis treated with TCA-placebo combination. The duration of the study was 4 weeks under double-blind conditions.

RESULTS

Initial lithium-TCA treatment reduced depressive symptoms significantly more than TCA alone. The difference was evident from 1^st week onward and persisted at 4 weeks.

CONCLUSION

Lithium augmentation of TCA at the outset offers a strategy to reduce the lag period of antidepressant action. The choice can be made for those patients who are likely to benefit from long-term prophylaxis.

Nortriptyline in knee osteoarthritis (NortIKA Study): study protocol for a randomised controlled trial

BACKGROUND

Osteoarthritis (OA) is a common cause of pain and disability. Currently available analgesics are often insufficiently effective or have unacceptable adverse effects. Tricyclic antidepressants may offer a useful centrally-acting analgesic. Nortriptyline is a readily-available, cheap and comparatively well-tolerated tricyclic antidepressant.

METHODS/DESIGN

We will conduct a parallel group, two-arm, participant and investigator-blinded, randomised controlled superiority trial comparing nortriptyline with placebo. Two hundred participants with primary knee OA will be enrolled. Participants will take study medication for 14 weeks. The primary outcome is difference between treatment arms in mean pain score measured on the Western Ontario and McMaster Universities (WOMAC) pain scale at 14 weeks.

DISCUSSION

This protocol describes the first randomised controlled trial of a tricyclic antidepressant in the treatment of OA. The results of the study may have significant implications for the management of this common and painful condition.

TRIAL REGISTRATION

The trial was registered with the Australian New Zealand Clinical Trials Registry on 27 June 2014. The trial registration number is: ACTRN12614000683639 .

Antidepressant use and risk of coronary heart disease: meta-analysis of observational studies

AIMS

Our goal was to evaluate the association between antidepressant use and the risk of coronary heart disease (CHD) among subjects with no history of coronary heart disease.

METHODS

A search of Medline, EMBASE, PsycINFO and the Cochrane Library was performed in January 2013. Two authors independently reviewed and selected eligible observational studies, based on predetermined selection criteria. Pooled relative risks (RRs) with confidence intervals (CIs) were calculated using random-effects or fixed-effects models.

RESULTS

Sixteen observational studies (seven case-control studies and nine cohort studies) were included in the final analysis. There was no association between selective serotonin reuptake inhibitor use and the risk of CHD overall [odds ratio (OR), 0.93; 95% CI, 0.65-1.33] or in subgroup meta-analysis of case-control studies (OR, 0.91; 95% CI, 0.60-1.37) and cohort studies (RR, 0.96; 95% CI, 0.59-1.55). The use of tricyclic antidepressant was associated with an increased risk of CHD overall (OR, 1.51; 95% CI, 1.07-2.12), but it was observed only in case-control studies (OR, 1.56; 95% CI, 1.24-1.96) and low-quality studies (OR, 1.49; 95% CI, 1.20-1.85) in the subgroup meta-analyses.

CONCLUSIONS

This meta-analysis of observational studies in subjects with no history of CHD suggests that neither selective serotonin reuptake inhibitor nor tricyclic antidepressant use is associated with an increased risk of CHD.

Tricyclic Antidepressants Amitriptyline and Desipramine Induced Neurotoxicity Associated with Parkinson's Disease

Recent studies report that a history of antidepressant use is strongly correlated with the occurrence of Parkinson's disease (PD). However, it remains unclear whether antidepressant use can be a causative factor for PD. In the present study, we examined whether tricyclic antidepressants amitriptyline and desipramine can induce dopaminergic cell damage, both in vitro and in vivo. We found that amitriptyline and desipramine induced mitochondria-mediated neurotoxicity and oxidative stress in SH-SY5Y cells. When injected into mice on a subchronic schedule, amitriptyline induced movement deficits in the pole test, which is known to detect nigrostriatal dysfunction. In addition, the number of tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta was reduced in amitriptyline-injected mice. Our results suggest that amitriptyline and desipramine may induce PD-associated neurotoxicity.

Cardiovascular adverse reactions during antidepressant treatment: a drug surveillance report of German-speaking countries between 1993 and 2010

BACKGROUND

Antidepressants (ADs) are known to have the potential to cause various cardiovascular adverse drug reactions (ADRs). The tricyclic antidepressants (TCAs) were first revealed to be a possible source of cardiovascular ADRs. In recent years, newer classes of ADs were also suggested to have a higher risk of cardiovascular adverse effects. In particular, the selective serotonin reuptake inhibitors (SSRIs) were suspected to have the potential to induce QTc interval prolongation, and therefore increase the risk of ventricular arrhythmia. This descriptive study is based on the continuous pharmacovigilance program of German-speaking countries (Austria, Germany, and Switzerland), the Arzneimittelsicherheit in der Psychiatrie (AMSP), which assesses severe ADRs occurring in clinical routine situations.

METHODS

Of 169,278 psychiatric inpatients treated with ADs between 1993 and 2010, 198 cases of cardiovascular ADRs (0.12%) were analyzed.

RESULTS

Our study showed that the incidence rates of cardiovascular ADRs were highest during treatment with monoamine oxidase inhibitors (0.27%), TCAs (0.15%), and serotonin noradrenaline reuptake inhibitors (0.14%); the risk of occurring during treatment with SSRIs (0.08%) was significantly lower. The noradrenergic and specific serotonergic AD mirtazapine (0.07%) had a significantly lower risk of cardiovascular ADRs than all other ADs. Severe hypotension was the most frequent ADR, followed by hypertension, arrhythmia, and in some rare cases heart failure.

CONCLUSIONS

Despite certain limitations due to the AMSP study design, our observations on cardiovascular ADRs can contribute to a better knowledge of the cardiovascular risk profiles of antidepressants in the clinical routine setting. However, prospective studies are needed to verify our findings.

Extracorporeal life support and plasmapheresis in a case of severe polyintoxication

BACKGROUND

Resuscitation without return to spontaneous circulation in patients with suicidal ingestion of cardiotoxic drugs necessitates alternative bridging therapies for drug removal.

OBJECTIVES

To show the effectiveness of emergency extracorporeal membrane oxygenation (ECMO) and plasmaspheresis in severe polyintoxication.

CASE REPORT

A 21-year-old woman developed asystole after suicidal polyintoxication with 1.75 g carvedilol, 300 mg amlodipine, 6 g amitriptyline, 500 mg torsemide, 1.5 g ketoprofen, 28 g nicotinic acid, and 16 g gabapentin. After 3 h of cardiopulmonary resuscitation without return to spontaneous circulation, ECMO was used as a bridging therapy and a temporary pacemaker was inserted. Plasma peak levels were measured for amlodipine (29.3 μg/L), amitriptyline (1456 μg/L), carvedilol (585 μg/L), and gabapentin (126.8 mg/L). To facilitate drug removal, therapeutic plasma exchange was performed. The patient could be weaned from ECMO at day 4 and extubated on day 8 after admission without neurologic sequelae.

CONCLUSION

ECMO and plasma exchange should be considered as a therapeutic option in selected patients under resuscitation without return to spontaneous circulation after severe intoxication.

ST-T segment changes in patients with tricyclic antidepressant poisoning

Objective:

Tricyclic antidepressant (TCA) poisoning is among highly prevalent and potentially dangerous toxicities. ST-T changes are observed in the electrocardiogram (ECG) of most of TCA poisoned patients. We aimed to study ST-T segment changes in TCA toxicity and its probable relationship with other ECG findings.

Methods:

This retrospective study was carried out in Noor and Ali Asghar University Hospital, Isfahan (Iran) in 2012. Patients with TCA toxicity based on the patients’ history who had not consumed any cardio-active drugs and did not have a past medical history of cardiovascular disease in the recent 5 years, were randomly selected and investigated. Their demographic and medical data on admission including ECG, age, sex, type and amount of ingested TCA, poisoning severity score, QRS changes, QT interval, heart axis position and R-wave were all recorded. ST-T changes and their relation with other ECG parameters have been determined using statistical analysis.

Findings:

Medical records of 272 patients were analyzed. In symptomatic patients, ST change prevalence was 40.8% and T change prevalence was 9.5%. In asymptomatic patients, the frequency of ST and T changes were 4.8% and 0.8%, respectively (P < 0.05). The most common ST and T changes in baseline (on admission) ECG were non-significant elevation (15.4%), significant elevation (11%) in pre-cordial leads, and T-wave flattening (6.6%). A statistically significant correlation was documented between ST segment changes with QRS and R-wave in aVR. The correlation between T-wave changes and R-wave in aVR lead was also significant.

Conclusion:

ST-T changes in TCA poisoned patients are more prevalent in symptomatic patients. Obviously for a more definite conclusion, it is necessary to design a prospective study with the control group. This may facilitate a better understanding of ST-T segment changes.

Selective serotonin reuptake inhibitors versus tricyclic antidepressants in young patients: a meta-analysis of efficacy and acceptability

PURPOSE

A meta-analysis comparing the efficacy and acceptability of selective serotonin reuptake inhibitors (SSRIs) versus tricyclic antidepressants (TCAs) in depressed children, adolescents, and young adults was performed.

METHODS

A comprehensive literature search of the PubMed, Cochrane, Embase, Web of Science, and PsycINFO databases was conducted from 1970 to December 2013. Only clinical trials that randomly assigned one SSRI or TCA to patients aged 7 to 25 years who met the diagnostic criteria for unipolar depressive disorder were included. Primary efficacy was determined by the pooling of standardized mean differences (SMDs) calculated from the difference in the reduction in mean depression rating scale scores for the 2 antidepressants. Acceptability was determined by pooling the risk ratios (RRs) of dropouts for all reasons and for adverse effects as well as the suicide-risk outcome.

FINDINGS

Five trials with a total of 422 patients were considered to be eligible for inclusion. SSRIs were significantly more effective than TCAs in primary efficacy (SMD = -0.52; 95% CI, -0.81 to -0.24; P = 0.0003). Patients taking SSRIs had a significantly greater response to depressive symptoms than patients taking TCAs (RR = 1.55; 95% CI, 1.04 to 2.29; P = 0.03). On an individual SSRI basis, fluoxetine had a significantly greater efficacy than TCAs (SMD = -0.82; 95% CI, -1.34 to -0.29; P = 0.003). On an individual TCA basis, only imipramine was not significantly worse than SSRIs (SMD = -0.27; 95% CI, -0.56 to 0.02; P = 0.06). Significantly more patients taking TCAs discontinued treatment than patients taking SSRIs (35.8% vs 25.1%; RR = 0.70; 95% CI, 0.52 to 0.93; P = 0.02).

IMPLICATIONS

SSRI therapy has a superior efficacy and is better tolerated compared with TCA therapy in young patients.

Glucosylceramide and lysophosphatidylcholines as potential blood biomarkers for drug-induced hepatic phospholipidosis

Drug-induced phospholipidosis is one of the major concerns in drug development and clinical treatment. The present study involved the use of a nontargeting lipidomic analysis with liquid chromatography-mass spectrometry to explore noninvasive blood biomarkers for hepatic phospholipidosis from rat plasma. We used three tricyclic antidepressants (clomipramine [CPM], imipramine [IMI], and amitriptyline [AMT]) for the model of phospholipidosis in hepatocytes and ketoconazole (KC) for the model of phospholipidosis in cholangiocytes and administered treatment for 3 and 28 days each. Total plasma lipids were extracted and measured. Lipid molecules contributing to the separation of control and drug-treated rat plasma in a multivariate orthogonal partial least squares discriminant analysis were identified. Four lysophosphatidylcholines (LPCs) (16:1, 18:1, 18:2, and 20:4) and 42:1 hexosylceramide (HexCer) were identified as molecules separating control and drug-treated rats in all models of phospholipidosis in hepatocytes. In addition, 16:1, 18:2, and 20:4 LPCs and 42:1 HexCer were identified in a model of hepatic phospholipidosis in cholangiocytes, although LPCs were identified only in the case of 3-day treatment with KC. The levels of LPCs were decreased by drug-induced phospholipidosis, whereas those of 42:1 HexCer were increased. The increase in 42:1 HexCer was much higher in the case of IMI and AMT than in the case of CPM; moreover, the increase induced by IMI was dose-dependent. Structural characterization determining long-chain base and hexose delineated that 42:1 HexCer was d18:1/24:0 glucosylceramide (GluCer). In summary, our study demonstrated that d18:1/24:0 GluCer and LPCs are potential novel biomarkers for drug-induced hepatic phospholipidosis.

Antidepressant-like activity of the adenosine A(2A) receptor antagonist, istradefylline (KW-6002), in the forced swim test and the tail suspension test in rodents

RATIONALE

Depression is common in Parkinson's disease (PD) but its response to classical antidepressants is not clear. The adenosine A2A antagonist istradefylline is effective in the treatment of the motor symptoms of PD but inhibition of the adenosine A2A receptor may also induce antidepressant-like effects.

OBJECTIVE

We have investigated whether istradefylline might be effective in treating depression in PD using the forced swimming test (FST) and the tail suspension test (TST) in rodents.

RESULTS

Istradefylline significantly decreased immobility time in the FST in both rats and mice (0.16mg/kg and higher) with comparable efficacy to an equivalent dose of the tricyclic antidepressants, desipramine and imipramine. Both 8-OH-DPAT (5-HT1A agonist) and quinpirole (D2 agonist) also reduced the immobility time. The istradefylline-induced reduction of immobility time was attenuated by corticosterone. In addition, the combined use of a sub-threshold dose of istradefylline and the serotonin-noradrenaline reuptake inhibitor venlafaxine ameliorated depression-like behavior in the mouse FST. In the mouse TST, istradefylline (0.08mg/kg and higher) decreased immobility time. Moreover, co-administration of istradefylline with paroxetine or fluoxetine (selective serotonin reuptake inhibitors) or deprenyl (MAO-B inhibitor) at doses that did not show antidepressant-like effects when administered alone, resulted in a significant reduction in immobility time.

CONCLUSIONS

Istradefylline alone or co-administered with currently available antidepressants, may be useful for the treatment of depression as well as motor symptoms of PD. Its effects might be, at least in part, attributable to modulation of hypothalamic-pituitary-adrenal axis.

Animal models of the serotonin syndrome: a systematic review

The serotonin syndrome (SS) is a potentially life-threatening disorder in humans which is induced by ingestion of an overdose or by combination of two or more serotonin (5-HT)-enhancing drugs. In animals, acute administration of direct and indirect 5-HT agonists also leads to a set of behavioral and autonomic responses. In the current review, we provide an overview of the existing versions of the animal model of the SS. With a focus on studies in rats and mice, we analyze the frequency of behavioral and autonomic responses following administration of 5-HT-enhancing drugs and direct 5-HT agonists administered alone or in combination, and we briefly discuss the receptor mediation of these responses. Considering species differences, we identify a distinct set of behavioral and autonomic responses that are consistently observed following administration of direct and indirect 5-HT agonists. Finally, we discuss the importance of a standardized assessment of SS responses in rodents and the utility of animal models of the SS in translational studies, and provide suggestions for future research.

Effects of different doses of doxepin on passive avoidance learning in rats

BACKGROUND

Studies have shown that Doxepin has anti-inflammatory effects and reduces oxidative stress. Due to the fact that other tricyclic antidepressants have been shown to have neuroprotective effects, this study aimed to investigate the effects of different doses of doxepin on passive avoidance learning in rats.

MATERIALS AND METHODS

Old male Wistar rats were used in this study. Doxepin was administered intraperitoneally (1, 5 and 10 mg/kg) for 21 days. Passive avoidance learning test was used for evaluation of learning and memory. Rats received foot electrical shock on fifteen day, and step through latencies were evaluated one week after the electrical shock in retention phase.

RESULTS

Administration of Doxepin considerably increased the step through latencies in the rats that received the doses of 1 and 5 mg/kg (P < 0.05). However, in the dose of 10 mg/kg, there wasn't any significant change comparing to control group.

CONCLUSION

These results indicate that Doxepin has desirable effects on cognitive functions in low doses. Therefore, Doxepin can be considered as memory enhancers that understanding the underling mechanisms need further investigation.

The clinical pharmacology of depressive states

Antidepressants have good efficacy in the treatment of mood disorders, with effect sizes that have consistently been found to be greater than those of placebo. The more recent antidepressants do not have better efficacy than the compounds discovered 40 to 50 years ago, but they do have a more favorable configuration of side effects, leading to fewer dropouts. This favorable situation has made it possible to prescribe the newer antidepressants in less severe depression and in several anxiety disorders, with considerable benefit to patients. During the last decades, research into the pathophysiology of mood and anxiety disorders has provided much information on the brain circuitry, neurohormones, and neurotransmitters involved in these disorders. In parallel, biological and behavioral work on antidepressants, using animal models and new biochemical techniques, has led to a broader understanding of the mode of action of these drugs. Despite this impressive list of discoveries, much research remains to be done on the clinical, psychological, neuropsychological, physiological, and neurochemical aspects, before we can obtain a coherent description of the pathophysiological mechanisms of depression and its treatment. This will lead to a better ability to predict the quality of drug response and, therefore, to the individualization of treatment.

Increased plasma norepinephrine concentration in psychotic depression

OBJECTIVE

We previously found psychotic depression (PSDEP) to have positively correlating plasma norepinephrine (NE) and vasopressin (AVP) concentrations. Since central noradrenergic activity and plasma NE concentration are highly correlated, this suggests an increased noradrenergic activation of the hypothalamus-pituitary-adrenal axis. We hypothesize the increased release of NE in PSDEP to be an associated mechanism.

METHODS

To test this hypothesis we analyzed the relation between plasma NE and PSDEP in a comparison with non-psychotically depressed patients. Potentially confounding variables were, among others, melancholia and two better validated subcategories in the field of melancholia and endogenous depression, three global dimensions of psychopathology - Emotional Dysregulation, Retardation and Anxiety - smoking habit, and different types of psychotropic and particularly antidepressant treatment. The data from nine patients with PSDEP and 69 patients with non-PSDEP were reanalysed.

RESULTS

Analysis of covariance controlling for the effects of tricyclic antidepressant treatment (≥100 mg) and smoking habit showed that PSDEP had an increased concentration of plasma NE. The previously found correlation between plasma NE and AVP was still present after correcting for the effects of confounding variables.

CONCLUSIONS

The results suggest an increased activity of the sympathetic nervous system in PSDEP that may act as a specific mechanism for increased vasopressinergic activation. This supports the view of PSDEP as a distinct subcategory of major depression.

Rapid improvement of depressive symptoms in suicide attempters following treatment with milnacipran and tricyclic antidepressants - a case series

Suicide is a serious social problem in many countries, including Japan. The majority of people who commit suicide suffer from depression. Suicide attempt patients suffering from serious physical injuries are initially treated in hospital emergency departments. The present post hoc analysis examined data from patients admitted to an emergency hospital for treatment of physical injuries, resulting from a suicide attempt, and initial psychiatric treatment for depression and prevention of future suicide attempts. The effects on depressive symptoms were studied in two groups of patients using the 17-item Hamilton depression scale (HAMD). One group (n = 6) had received intravenous tricyclic antidepressants (TCA) (amitriptyline or clomipramine) while the other group (n = 7) had been treated orally with milnacipran, a serotonin and norepinephrine reuptake inhibitor antidepressant. Prior to treatment the four highest scoring items on the HAMD scale were the same in both groups namely, item 1 (depressed mood), item 3 (suicidality), item 7 (interest in work and activities), and item 10 (psychic anxiety). After 1 week of treatment, mean global HAMD scores were significantly reduced in both groups. Treatment resulted in a significant reduction of five HAMD items in the TCA group, whereas in the milnacipran group 12 HAMD items were significantly reduced. Suicidality (item 3) was significantly improved by 1 week treatment with milnacipran, but not by TCAs. Milnacipran rapidly improved a wide range of depressive symptoms, including suicidality within the first week. The improvement with milnacipran would appear to be, at least, equivalent to that achieved with TCAs, possibly affecting a wider range of symptoms. Since milnacipran has been shown in comparative studies to be better tolerated than TCAs, this antidepressant offers an interesting option for the treatment of suicidal patients in an emergency setting.

Anti-depressant medication use and C-reactive protein: results from two population-based studies

The use of anti-depressant medication has been linked to cardiovascular disease (CVD). We examined the association between anti-depressant medication use and a marker of low grade systemic inflammation as a potential pathway linking anti-depressant use and CVD in two population based studies. Data were collected in a representative sample of 8131 community dwelling adults (aged 47.4±15.9 years, 46.7% male) from the Scottish Health Surveys (SHS). The use of anti-depressant medication was coded according to the British National Formulary and blood was drawn for the measurement of C-reactive protein (CRP). In a second study, we attempted to replicate our findings using longitudinal data from the Whitehall II study (n=4584, aged 55.5±5.9 years, mean follow-up 5.5 years). Antidepressants were used in 5.6% of the SHS sample, with selective serotonin reuptake inhibitors (SSRIs) being the most common. There was a higher risk of elevated CRP (>3 mg/L) in users of tricyclic antidepressant (TCA) medication (multivariate adjusted odds ratio (OR)=1.52, 95% CI, 1.07-2.15), but not in SSRI users (multivariate adjusted OR=1.07, 95% CI, 0.81-1.42). A longitudinal association between any antidepressant use and subsequent CRP was confirmed in the Whitehall cohort. In summary, the use of anti-depressants was associated with elevated levels of systemic inflammation independently from the symptoms of mental illness and cardiovascular co-morbidity. This might be a potential mechanism through which antidepressant medication increases CVD risk. Further data are required to explore the effects of dosage and duration of antidepressant treatment.

Gabapentin versus tricyclic antidepressants for diabetic neuropathy and post-herpetic neuralgia: discrepancies between direct and indirect meta-analyses of randomized controlled trials

BACKGROUND

Previous systematic reviews concluded that tricyclics antidepressants are superior to gabapentin for neuropathic pain, but were based on indirect comparisons from placebo-controlled trials.

PURPOSE

To evaluate gabapentin versus tricyclic antidepressants for diabetic neuropathy and post-herpetic neuralgia, using direct and indirect comparisons.

DATA SOURCES

MEDLINE (1966 to March Week 4 2008), the Cochrane central register of controlled trials (1st quarter 2008), and reference lists.

STUDY SELECTION

We selected randomized trials directly comparing gabapentin versus tricyclic antidepressants or comparing either of these medications versus placebo.

DATA EXTRACTION

Studies were reviewed, abstracted, and quality-rated by two independent investigators using predefined criteria.

DATA SYNTHESIS

We performed a meta-analysis of head-to-head trials using a random effects model and compared the results to an adjusted indirect analysis of placebo-controlled trials.

RESULTS

In three head-to-head trials, there was no difference between gabapentin and tricyclic antidepressants for achieving pain relief (RR 0.99, 95% CI 0.76 to 1.29). In adjusted indirect analyses, gabapentin was worse than tricyclic antidepressants for achieving pain relief (RR = 0.41, 95% CI 0.23 to 0.74). The discrepancy between direct and indirect analyses was statistically significant (p = 0.008). Placebo-controlled tricyclic trials were conducted earlier than the gabapentin trials, reported lower placebo response rates, had more methodological shortcomings, and were associated with funnel plot asymmetry.

CONCLUSIONS

Though direct evidence is limited, we found no difference in likelihood of achieving pain relief between gabapentin and tricyclic antidepressants for diabetic neuropathy and post-herpetic neuralgia. Indirect analyses that combine data from sets of trials conducted in different eras can be unreliable.

Treating smoking dependence in depressed alcoholics

Alcoholism and nicotine dependence share many neurobiological underpinnings; the presence of one drug can cause a person to crave the other. Depressive illness can complicate comorbid alcohol and nicotine dependence by exacerbating the negative affect encountered during attempts to abstain from one or both drugs. Given the morbidity and mortality associated with cigarette smoking, it is imperative to identify treatments to promote smoking cessation and address comorbid psychiatric conditions contemporaneously. Pharmacotherapeutic options demonstrating varying degrees of efficacy and promise in preclinical and clinical studies include nicotine replacement therapy (NRT), selective serotonin reuptake inhibitors (SSRIs), bupropion, varenicline, tricyclic antidepressants, and bupropion plus NRT. Topiramate has shown potential for promoting smoking cessation in alcoholics, although its safety in depressed patients has not been fully explored. The efficacy of medications for treating nicotine dependence is generally enhanced by the inclusion of behavioral interventions such as cognitive behavioral therapy. When group cohesion and social support are stressed, success rates increase among depressed smokers undergoing smoking cessation treatment. Additional treatment strategies targeting dually dependent individuals with comorbid psychiatric disorders, including special populations such as women and adolescents, await further investigation.

The clinical pharmacology of depressive states

Antidepressants have good efficacy in the treatment of mood disorders, with effect sizes that have consistently been found to be greater than those of placebo. The more recent antidepressants do not have better efficacy than the compounds discovered 40 to 50 years ago, but they do have a more favorable configuration of side effects, leading to fewer dropouts. This favorable situation has made it possible to prescribe the newer antidepressants in less severe depression and in several anxiety disorders, with considerable benefit to patients. During the last decades, research into the pathophysiology of mood and anxiety disorders has provided much information on the brain circuitry, neurohormones, and neurotransmitters involved in these disorders. In parallel, biological and behavioral work on antidepressants, using animal models and new biochemical techniques, has led to a broader understanding of the mode of action of these drugs. Despite this impressive list of discoveries, much research remains to be done on the clinical, psychological, neuropsychological, physiological, and neurochemical aspects, before we can obtain a coherent description of the pathophysiological mechanisms of depression and its treatment. This will lead to a better ability to predict the quality of drug response and, therefore, to the individualization of treatment.

Inhibition of the current of heterologously expressed HERG potassium channels by imipramine and amitriptyline

1 Tricyclic antidepressants (TCAs) are associated with cardiovascular side effects including prolongation of the QT interval of the ECG. In this report we studied the effects of two TCAs (imipramine and amitriptyline) on ionic current mediated by cloned HERG potassium channels. 2 Voltage clamp measurements of HERG currents were made from CHO cells transiently transfected with HERG cDNA. HERG-encoded potassium channels were inhibited in a reversible manner by both imipramine and amitriptyline. HERG tail currents (IHERG) following test pulses to +20 mV were inhibited by imipramine with an IC50 of 3.4+/-0.4 microM (mean+/-s.e.mean) and a Hill coefficient of 1.17+/-0.03 (n = 5). 3 microM amitriptyline inhibited IHERG by 34+/-6% (n = 3). The inhibition showed only weak voltage dependence. 3 Using an 'envelope of tails' comprised of pulses to +20 mV of varying durations, the tau of activation was found to be 155+/-30 ms for control and 132+/-26 ms for 3 microM imipramine (n = 5). Once maximal channel activation was achieved after 320 ms (as demonstrated by maximal tail currents), further prolongation of depolarization did not increase imipramine-mediated HERG channel inhibition. 4 Taking current measurements every second during a 10 s depolarizing pulse from -80 mV to 0 mV, block was observed during the first pulse in the presence of imipramine and the level of IHERG block was similar throughout the pulse (n=5). 5 A three pulse protocol (two depolarizing pulses to +20 mV separated by 20 ms at -80 mV) revealed that imipramine did not significantly alter the kinetics of IHERG inactivation. The tau of inactivation was 8+/-2 ms and 5.6+/-0.4 ms (n = 5) in the absence and presence of 3 microM imipramine, respectively, and currents inactivated to a similar extent. 6 Our data are consistent with TCAs causing components of block of the HERG channel in both the closed and open states. Any component of open channel block occurs rapidly upon depolarization. Inhibition of IHERG by the prototype TCAs imipramine and amitriptyline may suggest a mechanism for QT prolongation associated with risks of arrhythmia and sudden death that accompany high concentrations of TCAs following overdose.

Plasma-soluble marker for intraorgan regional flows

Measurement of regional plasma flow is needed to quantitate the delivery of substrates and drugs to cells. For estimating regional plasma flows an ideal deposition marker should be 100% extracted during transorgan passage and retained until local tissue concentrations can be measured. To escape quickly, the tracer must penetrate capillary endothelial cells rapidly. To be retained, it must bind or be transformed or accumulated by cells. Desmethylimipramine (DMI, mol wt 266.3), a norepinephrine reuptake inhibitor, is suitable. On injection of [3H]DMI and 131I-albumin simultaneously into the coronary artery inflow of isolated Ringer-perfused rabbit hearts at 37 degrees C, extractions were greater than 99% at plasma flows (Fs) up to 2.3 ml X g-1 X min-1 and greater than 94% with Fs up to 5.1. Retention at Fs less than 2.3 averaged 99.0 +/- 0.55% (SD, n = 6) at 0.5 min, 98.4 +/- 0.5% at 1 min, and 96.6 +/- 1.1% or greater than 95% at 3 min. Retentions were similar in two dog hearts in situ. With Fs greater than 3 ml X g-1 X min-1, there was greater escape, 4.2 +/- 2.7% at 1 min and 6.8 +/- 4.2% at 3 min. The fractional escape rates of loss at 2 min or more were about 1%/min at all flows, suggesting that the spatial profiles of deposition did not change thereafter. Thus DMI is nearly ideal as a "molecular microsphere."