Pharmacogenetics of selective serotonin reuptake inhibitors (SSRI): A serotonin reuptake transporter (SERT)-based approach

Neuropsychiatric disorders are considered to be the most common cause of disability worldwide. Serotonin and its transporter is a prominent paradigm in mood disorders. Response to selective serotonin reuptake inhibitors (SSRI) is altered due to heterogeneity in the serotonin transporter gene, SLC6A4 (solute carrier family 6 member 4). The reported polymorphisms are found to be in different regions of the transporter gene: promoter region (5-HTTLPR and various single nucleotide polymorphisms within it), intron (STin2), and exon 9 (I425V). The long and short alleles of the 5-HTTLPR gene, which are prevalent among variations, may mediate differential effects. In long allelic variant carriers, an increased response to SSRI and timely recovery is due to increased availability of SERT. Whereas, SERT availability is significantly decreased in short allelic carriers, necessitating a reduction in SSRI dosage due to the increased risk of adverse drug reactions. Thus, pharmacogenetic investigations are required to understand the impact of functional variations on the efficacy and tolerability of SSRI. Identifying the carrier variants may aid in clear-decision making of the treatment regimen, aiding the approach of personalized medication.

Use of psychotropic drugs among older patients with bladder cancer in the United States

OBJECTIVE

Older patients diagnosed with cancer are at increased risk of physical and emotional distress; however, prescription utilization patterns largely remain to be elucidated. Our objective was to comprehensively assess prescription patterns and predictors in older patients with bladder cancer.

METHODS

A total of 10,516 older patients diagnosed with clinical stage T1-T4a, N0, M0 bladder urothelial carcinoma from 1 January 2008 to 31 December 2012 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare were analyzed. We used multivariable analysis to determine predictors associated with psychotropic prescription rates (one or more). Medication possession ratio (MPR) was used as an index to measure adherence in intervals of 3 months, 6 months, 1 year, and 2 years. Evaluation of psychotropic prescribing patterns and adherence across different drugs and demographic factors was done.

RESULTS

Of the 10,516 older patients, 5621 (53%) were prescribed psychotropic drugs following cancer diagnosis. Overall, 3972 (38%) patients had previous psychotropic prescriptions prior to cancer diagnosis, and these patients were much more likely to receive a post-cancer diagnosis prescription. Prescription rates for psychotropic medications were higher among patients with higher stage BC (p < 0.001). Gamma aminobutyric acid modulators/stimulators and serotonin reuptake inhibitors/stimulators were the highest prescribed psychotropic drugs in 21% of all patients. Adherence for all drugs was 32% at 3 months and continued to decrease over time.

CONCLUSION

Over half of the patients received psychotropic prescriptions within 2 years of their cancer diagnosis. Given the chronicity of psychiatric disorders with observed significantly low adherence to medications that warrants an emphasis on prolonged patient monitoring and further investigation.

Psychopharmacology in cancer

Depression, anxiety, delirium, and other psychiatric symptoms are highly prevalent in the cancer setting, and pharmacological intervention is an important component in the overall psychosocial care of the patient. Psychopharmacology is also used as a primary or adjuvant treatment for the management of cancer-related symptoms stemming from the disease itself and/or its treatment, including sleep disturbance, loss of appetite, neuropathic pain, nausea, fatigue, and hot flashes. Psychiatrists, oncologists, and palliative care physicians working as members of a multidisciplinary team have the opportunity to target multiple symptoms that negatively affect a patient's quality of life with the strategic use of psychotropic medications when deemed appropriate. This article aims to review the indications for use of antidepressants, psychostimulants, anxiolytics, antipsychotics, and mood stabilizers in oncology. An updated review of the relevant literature is discussed and referenced in each section.

How are patient populations characterized in studies investigating depression in advanced cancer? Results from a systematic literature review

CONTEXT

Prevalence rates of depression in patients with advanced cancer vary considerably. This may be because of heterogeneous samples and use of different assessment methods. Adequate sample descriptions and consistent use of measures are needed to be able to generalize research findings and apply them to clinical practice.

OBJECTIVES

Our objective was twofold: First, to investigate which clinically important variables were used to describe the samples in studies of depression in patients with advanced cancer; and second, to examine the methods used for assessing and classifying depression in these studies.

METHODS

PubMed, PsycINFO, Embase, and CINAHL were searched combining search term groups representing "depression," "palliative care," and "advanced cancer" covering 2007-2011. Titles and abstracts were screened, and relevant full-text articles were evaluated independently by two authors. Information on 32 predefined variables on cancer disease, treatment, sociodemographics, depression-related factors, and assessment methods was extracted from the articles.

RESULTS

After removing duplicates, 916 citations were screened of which 59 articles were retained. Age, gender, and stage of the cancer disease were the most frequently reported variables. Depression-related variables were rarely reported, for example, antidepressant use (17%) and previous depressive episodes (12%). Only 25% of the studies assessed and classified depression according to a validated diagnostic system.

CONCLUSION

Current practice for describing sample characteristics and assessing depression varies greatly between studies. A more standardized practice is recommended to enhance the generalizability and utility of findings. Stakeholders are encouraged to work toward a common standard for sample descriptions.

Mental adjustment to cancer: the role of anxious and depressive symptoms under treatment

OBJECTIVE

Depression is a risk factor for poor quality of life and mental adjustment to cancer. This research aims to evaluate the course of mental adjustment to illness of cancer patients with anxious-depressive symptoms who receive antidepressant therapy (ADT).

METHOD

Eighty oncological patients with and without depressive symptoms were divided into three groups. Group 1: 30 depressed cancer patients who underwent ADT with SSRI; Group 2: 30 depressed cancer patients who refused ADT; Group 3: 20 non-depressed cancer patients. Patients were evaluated at tO and 4 (tl) and 12 (t2) weeks later through: Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HARS), Hospital Anxiety Depression Scale (HADS), and MINI-MAC.

RESULTS

HDRS and HARS mean scores were stable and under threshold across the study only in Group 3; at t2 they improved in Group 1 and worsened in Group 2. The improvements in anxiety and depression scores were associated with ADT and related to the changes in Mini-MAC helpless-hopeless, anxious preoccupations, cognitive avoidance and fighting spirit dimensions.

CONCLUSION

The improvement of mental adjustment to illness is directly related to the decrease of anxious-depressive symptoms among depressed cancer patients under antidepressant therapy.

Treatment of depressive symptoms in patients with cancer

Depression is the most common psychological condition in patients with cancer. These patients often have worse outcomes, such as decreased adherence to treatment and increased suicide rates. Since depression is common and often under recognized in this patient population, guidelines recommend screening every patient with cancer for depression. Both psychotherapy and pharmacotherapy are shown to be effective to treat depression in patients with cancer. Psychotherapy, specifically cognitive behavioral therapy, is preferred in patients with more mild depressive symptoms, while pharmacotherapy is used for more severe depression. Dignity therapy and supportive-expressive therapy are also recommended for patients near the end of life. Pharmacotherapeutic options for treatment include antidepressants and psychostimulants. Guidelines recommend SSRIs, SNRIs, or mirtazapine as first line treatment, with TCAs often avoided due to side effects. Psychostimulants, such as modafinil and methylphenidate, can be used as well, and are especially effective for patients near the end of life. SSRIs may also be useful to prevent the development of depression in patients taking drugs known to cause depression, such as interferon alfa. Treatment of depression in patients with cancer should be based on patient specific symptoms and situation. This article will review both non-pharmacologic and pharmacologic treatment options in patients with cancer and comorbid depression.

Evidence-Based Treatment of Depression in Patients With Cancer

Purpose

Depression is a common condition in patients with cancer, although there has been a relative paucity of research on the effectiveness of treatment in this population. This review summarizes the psychosocial and pharmacologic treatment of depression in patients with cancer based on a consideration of evidence regarding etiologic factors and treatment outcomes.

Methods

A review of the evidence base for psychosocial and pharmacologic interventions for depression in patients with cancer was performed, including original studies, systematic reviews, and meta-analytic studies in the literature.

Results

Recent evidence from randomized controlled trials has demonstrated the efficacy of psychosocial and pharmacologic treatments to alleviate depression in patients with cancer. Further research is needed to establish their relative and combined efficacy and their role in the treatment of depression that is less severe and occurs in association with more advanced disease. First-line recommendations for the treatment of depression in patients with cancer are difficult to derive based on current evidence, because comparative studies have not been conducted to support the superiority of one treatment modality over another in this population.

Conclusion

Both psychosocial and pharmacologic interventions have been shown to be efficacious in treating depression in cancer, but further research is needed to establish their relative and combined benefit. Future research directions include the development and evaluation of novel interventions targeted to specific biologic and psychosocial risk factors.