Impact of Cytochrome P450 Genetic Variation on Patient-Reported Symptom Improvement and Side Effects Among Children and Adolescents Treated with Fluoxetine.

Background: Clinical practice guidelines recommend the use of fluoxetine, a selective serotonin reuptake inhibitor (SSRI), as a first-line pharmacotherapy for major depressive disorder (MDD) and obsessive compulsive disorder (OCD) in children and adolescents. However, response and tolerability to fluoxetine varies from child to child, which may in part, be a result of interindividual differences in fluoxetine metabolism. In this study, we examined whether genotype-predicted activity scores of cytochrome P450 enzymes were associated with patient-reported symptom improvement and side effects in children and adolescents treated with fluoxetine. Methods: Ninety children and adolescents aged 7-18 with a MDD or OCD diagnosis and a history of fluoxetine treatment were recruited from Western Canada. For each participant, fluoxetine dose and duration information were collected, as well as questions about adherence, side effects, and symptom improvement. DNA was extracted from a saliva sample and genotyped for CYP2D6, CYP2C19, CYP2C9, CYP3A4, and CYP3A5. Logistic regression models were fitted to assess the impact of activity scores on symptom improvement and side effects. Results: Increased CYP2D6 activity score was significantly associated with reduced odds of symptom improvement (odds ratio [OR] = 0.46, 95% confidence interval [CI] = 0.23-0.91, p = 0.028) as well as a trend association with reduced side effects (OR = 0.49, 95% CI = 0.22-1.07, p = 0.072), after adjusting for age, sex, diagnosis, dose, duration, adherence, and activity scores of the other assessed CYP enzymes. No associations with symptom improvement or side effects were detected for the other CYP enzymes examined. Conclusions: Our results suggest that an increase in the genotype-predicted CYP2D6 activity score was associated with a decrease in the odds of reporting symptom improvement among children and adolescents treated with fluoxetine. These findings will contribute to future updates of pharmacogenetic-based SSRI prescribing guidelines and if replicated, could inform fluoxetine treatment in children and adolescents with MDD or OCD. Clinical Trial Registration: NCT04797364.

Generalized seizures after acute fluoxetine overdose in four adolescents.

Fluoxetine is a selective serotonin reuptake inhibitor that is less frequently associated with severe toxicity in acute overdose compared with other psychotropic medications. Although rare, generalized seizure has been reported after isolated fluoxetine overdose. Most cases in the literature have occurred between one- and 16 h following acute ingestion of ≥1000 mg. Here, we present a series of four cases of adolescents who presented to our pediatric emergency department with reported or witnessed seizures after acute fluoxetine overdose between 3/2021 and 1/2022. These cases included intentional ingestions of fluoxetine at doses between 600 and 1200 mg (10-19.5 mg/kg), each of whom had a single, witnessed episode of generalized seizure activity which occurred between three- and nine-hours post-ingestion. All patients had signs of mild serotonin excess and two met conventional criteria for diagnosis of serotonin toxicity. All patients were evaluated by a medical toxicologist and were hospitalized for observation. No patient developed subsequent seizure or further complications related to overdose and no patient received neuroimaging, electroencephalography, or evaluation by a neurologist. Though previously described, seizure is an uncommon and potentially underappreciated complication after fluoxetine overdose and occurred in some of our patients at doses lower than those which have typically been reported in the literature.

CYP450 Genetic Polymorphisms: Generalized Tonic-Clonic Seizure after Intentional Fluoxetine and Melatonin Overdose.

Cytochrome P450 polymorphisms have gathered much attention regarding personalized psychopharmacological care. It is well documented that these drug metabolizing enzymes lead to interpatient variability in pharmacokinetic profiles. It appears that less functional genotype may increase of risk of higher side-effect burden. Here we highlight the importance of genetic polymorphisms to potentially predict a toxicity related phenotype after an intentional overdose. Genotyping may have a role in predicting serious side effects to help clinicians educate patients and their families, and implement more intensive monitoring and institute prophylactic treatment as needed.

Hypothermia as a Possible Symptom of Serotonin Toxicity: A Case Report.

Background There are three commonly used sets of criteria to diagnose serotonin syndrome and all three diagnostic tools have all been shown to have shortcomings that do not fully encompass the possible symptoms of serotonin toxicity. Objective To describe a case of an atypical presentation of possible drug-induced serotonin syndrome, characterized by hypothermia, night sweats, muscle tremors, and confusion. Setting A rural and medically underserved area in eastern Washington State. Practice Description This patient case was identified as a part of a project to identify and intervene with complex and high-risk patients from local rural and underserved populations. The pharmacist identified the symptoms of possible drug-induced serotonin syndrome during a comprehensive medication review with the patient. Results The pharmacist identified a possible case of drug-induced serotonin syndrome and made a recommendation to the patient's physician that led to discontinuation of both fluoxetine and trazodone. At the follow-up visit, the patient reported that his symptoms had resolved completely. Discussion The three sets of diagnostic criteria for serotonin syndrome all include fever as a symptom, but do not list hypothermia. Effects at various 5-HT receptors and receptor subtypes have been linked to symptoms often seen in serotonin syndrome, but there are gaps in the currently used diagnostic criteria. Conclusion Pharmacists' comprehensive review of medications can allow identification of symptoms, such as hypothermia to identify possible serotonin syndrome.

Efficacy and safety of adding fluoxetine to the treatment regimen of hospitalized patients with non-critical COVID-19 pneumonia: A double-blind randomized, placebo-controlled clinical trial.

INTRODUCTION: Selective serotonin reuptake inhibitors are considered the drugs, whose effectiveness in viral pandemics has been studied. The aim of this study was to evaluate of adding fluoxetine to the treatment regimen of patients with COVID-19 pneumonia. METHODS: This study was a double-blind randomized placebo controlled clinical trial .36 patients in the fluoxetine and 36 patients in the placebo group were enrolled. Patients in the intervention group were first treated with fluoxetine 10 mg for 4 days and then the dose of 20 mg was continued for 4 weeks. Data analysis was conducted using SPSS V. 22.0. RESULTS: There was no statistically significant difference between the two groups in terms of clinical symptoms at the beginning of the study and also the score of anxiety and depression, oxygen saturation at the time of hospitalization, mid-hospitalization and discharge periods. The need for mechanical ventilator support (p = 1.00), the need for admission in the intensive care unit (ICU) (p = 1.00), rate for mortality (p = 1.00), and discharge with relative recovery (p = 1.00) were not significantly different between the two groups. The distribution of CRP within the study groups showed a significant decrease during different time periods (p = 0.001), and although there was no statistically significant difference between the two groups on the first day (p = 1.00) and at discharge (p = 0.585), mid-hospital CRP showed a significant decrease in the fluoxetine group (p = 0.032). CONCLUSION: Fluoxetine resulted in a faster reduction of patients' inflammation without association with depression and anxiety.

Safety outcomes of selective serotonin reuptake inhibitors in adolescent attention-deficit/hyperactivity disorder with comorbid depression: the ASSURE study.

BACKGROUND: Attention deficit-hyperactivity disorder (ADHD) is related to depressive disorder, and adolescents with both present poor outcomes. However, evidence for the safety of concomitantly using a methylphenidate (MPH) and a selective serotonin reuptake inhibitor (SSRI) among adolescent ADHD patients is limited, a literature gap aimed to address through this investigation. METHODS: We conducted a new-user cohort study using a nationwide claims database in South Korea. We identified a study population as adolescents who were diagnosed both ADHD and depressive disorder. MPH-only users were compared with patients who prescribed both a SSRI and a MPH. Fluoxetine and escitalopram users were also compared to find a preferable treatment option. Thirteen outcomes including neuropsychiatric, gastrointestinal, and other events were assessed, taking respiratory tract infection as a negative control outcome. We matched the study groups using a propensity score and used the Cox proportional hazard model to calculate the hazard ratio. Subgroup and sensitivity analyses were conducted in various epidemiologic settings. RESULTS: The risks of all the outcomes between the MPH-only and SSRI groups were not significantly different. Regarding SSRI ingredients, the risk of tic disorder was significantly lower in the fluoxetine group than the escitalopram group [HR 0.43 (0.25-0.71)]. However, there was no significant difference in other outcomes between the fluoxetine and escitalopram groups. CONCLUSION: The concomitant use of MPHs and SSRIs showed generally safe profiles in adolescent ADHD patients with depression. Most of the differences between fluoxetine and escitalopram, except those concerning tic disorder, were not significant.

Are all antidepressants the same? The consumer has a point.

BACKGROUND: Although a large variety of antidepressants agents (AD) with different mechanisms of action are available, no significant differences in efficacy and safety have been shown. However, there have been few attempts to incorporate data on subjective experiences under different AD. METHOD: We conducted a qualitative and quantitative analysis of the posts from the website www.askapatient.com from different AD. We reviewed a random sample of 1000 posts. RESULT: After applying the inclusion and exclusion criteria, we included a final sample of 450 posts, 50 on each of the most used AD: sertraline, citalopram, paroxetine, escitalopram, fluoxetine, venlafaxine, duloxetine, mirtazapine, and bupropion. Bupropion, citalopram, and venlafaxine had the higher overall satisfaction ratings. Sertraline, paroxetine, and fluoxetine had high reports of emotional blunting, while bupropion very few. Overall satisfaction with AD treatment was inversely associated with the presence of the following side-effects: suicidality, irritability, emotional blunting, cognitive disturbances, and withdrawal symptoms. After adjusting for confounders, only emotional blunting was shown to be more frequently reported by users of serotonergic agents, as compared to non-serotoninergic agents. CONCLUSION: This research points out that the subjective experience of patients under treatment should be taken into consideration when selecting an AD as differences between agents were evident. In contrast to the more frequent treatment decisions, users might prefer receiving a non-serotoninergic agent over a serotonergic one due to their lower propensity to produce emotional blunting.

The serotonin reuptake inhibitor fluoxetine induces human fetal membrane sterile inflammation through p38 MAPK activation.

Serotonin Reuptake Inhibitors (SRIs) are often used as first line therapy for depression and other psychiatric disorders. SRI use during pregnancy is associated with preterm premature rupture of membranes (PPROM) and subsequent preterm birth. The objective of this study was to investigate the mechanism(s) responsible for SRI-associated PPROM. Putative mechanisms underlying PPROM include fetal membrane (FM) inflammation, increased apoptosis, and/or accelerated senescence, the later which may be reversed by statins. Human FM explants from normal term deliveries without labor, infection, or antidepressant use were treated with or without the SRI, fluoxetine (FLX), either alone or in the presence of a p38 MAPK inhibitor or the statins, simvastatin or rosuvastatin. FMs were also collected from women either unexposed or exposed to FLX during pregnancy. FLX significantly increased FM p38 MAPK activity and secretion of inflammatory IL-6. Inhibition of p38 MAPK reduced FM IL-6 secretion in response to FLX. Statins did not reduce the SRI-induced FM IL-6 production. FMs from women exposed to FLX during pregnancy expressed elevated levels of p38 MAPK activity compared to matched unexposed women. FMs exposed to FLX did not exhibit signs of increased apoptosis and/or accelerated senescence. These results indicate that the SRI, FLX, may induce sterile FM inflammation during pregnancy through activation of the p38 MAPK pathway, and in the absence of apoptosis and senescence. These findings may better inform clinicians and patients as they weigh the risks and benefits of SRI antidepressant treatment during pregnancy.

Fluoxetine or Venlafaxine for Early Post Stroke Depression.

Context: Post stroke depression (PSD) is an under diagnosed morbidity of stroke and can negatively affect the prognosis of the patient. Aims: We intended to study the prevalence of PSD and the commonly used anti-depressants and their outcome in patients with PSD. Settings and Design: A prospective observational study was conducted in the patients admitted to the stroke unit of a tertiary care centre. Methods and Materials: Diagnosis of post stroke depression was made by the Hamilton Depression Rating Scale (HDRS) during the two-week period after stroke or in the clinic follow up. A comparison of clinical outcome and adverse events of the two anti-depressants used, i.e. venlafaxine and fluoxetine were done by a follow up of up to 6 months. Statistical Analysis Used: Independent sample test was used for statistical purposes in the study. Results: Out of the 326 stroke patients admitted in the department, 73 had PSD and 60 patients out of this were assigned into the study. Forty patients were males, and the mean age of the sample population was found to be 62.13 ± 11.14. Major risk factors identified were hypertension, diabetes mellitus, and dyslipidemia. Venlafaxine showed better outcome and less adverse events compared to fluoxetine. Major adverse events observed were hyponatremia, headache, insomnia, and anxiety. Conclusions: PSD in the early phase affects a substantial number of the stroke patients. Venlafaxine has got a better outcome and adverse event profile compared to fluoxetine in this group of patients. However, larger multicenter studies will provide more helpful data in this area.

Restoring the two pivotal fluoxetine trials in children and adolescents with depression.

BACKGROUND: Fluoxetine was approved for depression in children and adolescents based on two placebo-controlled trials, X065 and HCJE, with 96 and 219 participants, respectively. OBJECTIVE: To review these trials, which appear to have been misreported. METHODS: Systematic review of the clinical study reports and publications. The primary outcomes were the efficacy variables in the trial protocols, suicidal events, and precursors to suicidality or violence. RESULTS: Essential information was missing and there were unexplained numerical inconsistencies. (1) The efficacy outcomes were biased in favour of fluoxetine by differential dropouts and missing data. The efficacy on the Children's Depression Rating Scale-Revised was 4% of the baseline score, which is not clinically relevant. Patient ratings did not find fluoxetine effective. (2) Suicidal events were missing in the publications and the study reports. Precursors to suicidality or violence occurred more often on fluoxetine than on placebo. For trial HCJE, the number needed to harm was 6 for nervous system events, 7 for moderate or severe harm, and 10 for severe harm. Fluoxetine reduced height and weight over 19 weeks by 1.0 cm and 1.1 kg, respectively, and prolonged the QT interval. CONCLUSIONS: Our reanalysis of the two pivotal trials showed that fluoxetine is unsafe and ineffective.

Association between CYP metabolizer phenotypes and selective serotonin reuptake inhibitors induced weight gain: a retrospective cohort study.

BACKGROUND: Prescription medications such as selective serotonin reuptake inhibitors (SSRIs), commonly used to treat depression, are associated with weight gain. The role of pharmacogenomics in predicting SSRI-induced weight gain is unclear. METHODS: In this retrospective cohort study from participants in the Mayo Clinic RIGHT study who were prescribed citalopram, paroxetine, sertraline, or fluoxetine, our aim was to evaluate the association of metabolizer phenotype and total body weight after 6 months of SSRIs initiation. We evaluated the metabolizer phenotypes (poor/intermediate, normal, and rapid/ultra-rapid) of the cytochromes P450 enzymes genes: CYP2C9, CYP2C19, and CYP2D6 known to influence the metabolism of SSRI medications: CYP2C19 for citalopram, CYP2D6 for paroxetine, CYP2D6 and CYP2C19 for sertraline, and CYP2D6 and CYP2C9 fluoxetine. In addition, we assessed the association of metabolizer phenotype and total body weight change at six months following SSRI prescription using parametric analysis of covariance adjusted for baseline body weight and multivariate regression models. RESULTS: CYP2C19 poor/intermediate metabolizers prescribed citalopram gained significantly more weight than normal or rapid/ultra-rapid metabolizers at 6 months (TBWG %: 2.6 [95% CI 1.3-4.1] vs. 0.4 [95% CI -0.5 - 1.3] vs. -0.1 [-95% CI -1.5-1.1]; p = 0.001). No significant differences in weight outcomes at six months of treatment with paroxetine, sertraline, or fluoxetine were observed by metabolizer status. CONCLUSIONS: Weight gain observed with citalopram may be mediated by CYP2C19 metabolizer status.

Use of Fluoxetine to Reduce Weight in Adults with Overweight or Obesity: Abridged Republication of the Cochrane Systematic Review.

INTRODUCTION: Using fluoxetine is one of many weight loss strategies. A serotonin reuptake inhibitor indicated for depression believed to impact weight control by changing an individual's appetite; however, its benefit-risk ratio is unclear. The aim of this review was to assess the efficacy and safety of fluoxetine in reducing weight in adults with overweight or obesity. METHODS: We searched Cochrane Library, MEDLINE, Embase, and other databases without language restrictions. Cochrane Collaboration tool and GRADE instrument assessed the risk of bias of randomized controlled trials and certainty of their evidence. We conducted random-effects meta-analyses and calculated the risk ratio/mean difference with 95% confidence intervals for the outcomes. RESULTS: We included 19 trials (2,216 adults) and found that fluoxetine may reduce weight by -2.7 kg (95% CI -4 to -1.4; p < 0.001) and body mass index by -1.1 kg/m2 (95% CI -3.7 to 1.4), compared with placebo; however, it would cause approximately twice as many adverse events, such as dizziness, drowsiness, fatigue, insomnia, or nausea. CONCLUSIONS: Although low-certainty evidence suggests that off-label fluoxetine may reduce weight, high-certainty research is needed to be conducted in the future to determine its effects exclusively as well as whether it is useful when combined with other agents. This article is based on a Cochrane Review published in the Cochrane Database of Systematic Reviews 2019, Issue 10, DOI: 10.1002/14651858.CD011688.pub2. Cochrane Reviews are regularly updated as new evidence emerges, and in response to feedback, it should be consulted for the most recent version of the review.