Antidepressant drug interactions in the elderly. Understanding the P-450 system is half the battle in reducing risks

Association between tricyclic antidepressants and health outcomes among older people: A systematic review and meta-analysis

Tricyclic antidepressants are effective for managing depression and other disorders. However, they can cause adverse reactions due to their anticholinergic properties, with the risk of such events increasing with age. This study identifies and describes clinical studies that evaluate associations between the use of tricyclic antidepressants and adverse health outcomes (falls, fractures, and mortality) among older people. A systematic search of the literature in English, Spanish, and French was conducted using the electronic databases PubMed, ISI Web of Science, PsycINFO, and Cochrane. The systematic review included a total of 18 studies. The meta-analysis examined the 14 studies that investigated the association between the use of tricyclic antidepressants and the risk of falls and fractures (4 of the 18 studies focused on mortality and so were excluded from the meta-analysis). The odds ratio (OR) was 1.40 (95 % CI = 1.27-1.53, p < 0.001). The Cochran Q test was significant (X2 = 79.72, p < 0.001), indicating high heterogeneity (I2 = 84.9 %). An additional meta-analysis was conducted on studies reporting hazard ratios (HRs), yielding an HR of 1.21 (95 % CI = 0.93-1.58, p = 0.16). Meta-regression analysis indicated that the years of follow-up could have a significant effect on the association studied (p = 0.008). In conclusion, enhancing our understanding of the use of antidepressants and the associated risk of adverse events in older adults will enable the identification of the most appropriate type of antidepressant for each clinical situation.

Antidepressants and suicidal behaviour in late life: a prospective population-based study of use patterns in new users aged 75 and above

Purpose

To investigate associations between antidepressant use patterns and risk of fatal and non-fatal suicidal behaviours in older adults who initiated antidepressant therapy.

Method

A national population-based cohort study conducted among Swedish residents aged ≥ 75 years who initiated antidepressant treatment. Patients who filled antidepressant prescriptions between January 1, 2007 and December 31, 2013 (N = 185,225) were followed until December 31, 2014. Sub-hazard ratios of suicides and suicide attempts associated with use patterns of antidepressants, adjusting for potential confounders such as serious depression were calculated using the Fine and Gray regression models.

Results

During follow-up, 295 suicides and 654 suicide attempts occurred. Adjusted sub-hazard ratios (aSHRs) were increased for both outcomes in those who switched to another antidepressant (aSHR for suicide 2.42, 95% confidence interval 1.65 to 3.55, and for attempt 1.76, 1.32 to 2.34). Elevated suicide risks were also observed in those who concomitantly filled anxiolytics (1.54, 1.20 to 1.96) and hypnotics (2.20, 1.69 to 2.85). Similar patterns were observed for the outcome suicide attempt. Decreased risk of attempt was observed among those with concomitant use of anti-dementia drugs (0.40, 0.27 to 0.59).

Conclusion

Switching antidepressants, as well as concomitant use of anxiolytics or hypnotics, may constitute markers of increased risk of suicidal behaviours in those who initiate antidepressant treatment in very late life. Future research should consider indication biases and the clinical characteristics of patients initiating antidepressant therapy.

Electronic supplementary material

The online version of this article (10.1007/s00228-017-2360-x) contains supplementary material, which is available to authorized users.

Amitriptyline for musculoskeletal complaints: a systematic review

BACKGROUND

The role of amitriptyline in musculoskeletal pain is not as clearly defined as in classical neuropathic pain conditions.

OBJECTIVE

To assess the efficacy and effectiveness of amitriptyline in the treatment of pain in musculoskeletal complaints.

METHODS

An extensive search (including Medline, Embase and Web of Science) was made up to April 2016 for randomised controlled trials on amitriptyline in musculoskeletal complaints compared to placebo, usual care, or other analgesic use. Included studies were assessed for risk of bias. Outcomes of interest were pain reduction and function improvement.

RESULTS

Of the 2066 articles identified, seven were finally included. These studies were performed in patients with low back pain (4), rheumatoid arthritis (2), and patients with arm pain from repetitive use (1). No meta-analysis was performed due to clinical heterogeneity of the studies. Two studies with low risk of bias found positive results. One study found that 50 mg/day of amitriptyline [Visual Analogue Scale (VAS) -3.9 points] resulted in a significantly greater reduction in pain than treatment with pregabalin 600 mg/day (VAS -2.9 points) and improved function (improvement on the Oswestry Disability Index >20%: 65% versus 49.5%). Amitriptyline improved function in arm pain compared to placebo (Upper Extremity Function Scale: -3.9 versus 0.8). A similar amount of side-effects occurred in the amitriptyline and the comparison groups.

CONCLUSION

Few studies have evaluated the use of amitriptyline in musculoskeletal complaints. Although amitriptyline may be effective in musculoskeletal complaints, more studies are required to establish for whom amitriptyline works better than other analgesics.

Antidepressant use and mortality in very old people

BACKGROUND

Antidepressant treatment may increase the risk of death. The association between antidepressants and mortality has been evaluated in community-dwelling older people, but not in representative samples of very old people, among whom dementia, multimorbidity, and disability are common.

METHODS

Umeå 85+/GERDA study participants (n = 992) aged 85, 90, and ≥95 years were followed for up to five years. Cox proportional hazard regression models were used to analyze mortality risk associated with baseline antidepressant treatment, adjusted for potential confounders.

RESULTS

Mean age was 89 years; 27% of participants had dementia, 20% had stroke histories, 29% had heart failure, and 16% used antidepressants. In age- and sex-adjusted analyses, antidepressant use was associated with a 76% increased mortality risk (hazard ratio [HR] = 1.76; 95% confidence interval [CI], 1.41-2.19). Adding adjustment for Geriatric Depression Scale score, HR was 1.62 (95% CI, 1.29-2.03). The association was not significant when adjusting for additional confounding factors (HR = 1.08; 95% CI, 0.85-1.38). Interaction analyses in the fully adjusted model revealed a significant interaction between sex and antidepressant use (HR: 1.76; 95% CI, 1.05-2.94). Among male and female antidepressant users, the HRs for death were 0.76 (95% CI, 0.47-1.24) and 1.28 (95% CI, 0.97-1.70), respectively.

CONCLUSION

Among very old people, baseline antidepressant treatment does not seem to be independently associated with increased mortality risk. However, the risk may be different in men and women. This difference and the potential risk of initial treatment require further investigation in future cohort studies of very old people.

Adherence to pharmacological treatment and specific immunotherapy in allergic rhinitis

The term compliance simply indicates how much doses of the prescribed medication are taken, whereas the term adherence implies also an agreement between patient and physician about the therapeutic plan, and it is therefore preferred. Adherence is a main problem in all long-term treatments. Thus, it represents a problem also in the case of rhinitis, expecially concerning specific immunotherapy that must be assumed continuously for several years. Many factors can affect the adherence, depending on patient, on treatment itself and on the healthcare context, and all those factors usually interact. The adherence measured in controlled trials is usually good, but this does not reflect what happens in real life, where adherence should be preferably measured. There are few data on the adherence in real life for pharmacological treatments of allergic rhinitis (e.g. nasal steroids or antihistamines), whereas more data are available for specific immunotherapy. In this latter case, in real life, adherence seems to be far from optimal, for both sublingual and subcutaneous immunotherapy, although the recent studies agree on the fact that some interventions (i.e. patients' education, strict follow-up, regular contacts) could effectively improve the adherence. In this article, the literature concerning the adherence to pharmacological treatments and immunotherapy in allergic rhinitis was searched and reviewed.

Antidepressant use and risk of adverse outcomes in older people: population based cohort study

OBJECTIVES

To investigate the association between antidepressant treatment and risk of several potential adverse outcomes in older people with depression and to examine risks by class of antidepressant, duration of use, and dose.

DESIGN

Cohort study of people aged 65 and over diagnosed as having depression.

SETTING

570 general practices in the United Kingdom supplying data to the QResearch primary care database.

PARTICIPANTS

60,746 patients diagnosed as having a new episode of depression between the ages of 65 and 100 years from 1 January 1996 to 31 December 2007 and followed up until 31 December 2008.

MAIN OUTCOME MEASURES

Hazard ratios associated with antidepressant use for all cause mortality, attempted suicide/self harm, myocardial infarction, stroke/transient ischaemic attack, falls, fractures, upper gastrointestinal bleeding, epilepsy/seizures, road traffic accidents, adverse drug reactions, and hyponatraemia, adjusted for a range of potential confounding variables. Hazard ratios were calculated for antidepressant class (tricyclic and related antidepressants, selective serotonin reuptake inhibitors, other antidepressants), dose, and duration of use and for commonly prescribed individual drugs.

RESULTS

54,038 (89.0%) patients received at least one prescription for an antidepressant during follow-up. A total of 1,398,359 antidepressant prescriptions were issued: 764,659 (54.7%) for selective serotonin reuptake inhibitors, 442,192 (31.6%) for tricyclic antidepressants, 2203 (0.2%) for monoamine oxidase inhibitors, and 189,305 (13.5%) for the group of other antidepressants. The associations with the adverse outcomes differed significantly between the antidepressant classes for seven outcomes. Selective serotonin reuptake inhibitors were associated with the highest adjusted hazard ratios for falls (1.66, 95% confidence interval 1.58 to 1.73) and hyponatraemia (1.52, 1.33 to 1.75) compared with when antidepressants were not being used. The group of other antidepressants was associated with the highest adjusted hazard ratios for all cause mortality (1.66, 1.56 to 1.77), attempted suicide/self harm (5.16, 3.90 to 6.83), stroke/transient ischaemic attack (1.37, 1.22 to 1.55), fracture (1.64, 1.46 to 1.84), and epilepsy/seizures (2.24, 1.60 to 3.15), compared with when antidepressants were not being used. Tricyclic antidepressants did not have the highest hazard ratio for any of the outcomes. Significantly different associations also existed between the individual drugs for the same seven outcomes; trazodone (tricyclic antidepressant), mirtazapine, and venlafaxine (both in the group of other antidepressants) were associated with the highest rates for some of these outcomes. Absolute risks over 1 year for all cause mortality were 7.04% for patients while not taking antidepressants, 8.12% for those taking tricyclic antidepressants, 10.61% for selective serotonin reuptake inhibitors, and 11.43% for other antidepressants.

CONCLUSIONS

Selective serotonin reuptake inhibitors and drugs in the group of other antidepressants were associated with an increased risk of several adverse outcomes compared with tricyclic antidepressants. Among individual drugs, trazodone, mirtazapine, and venlafaxine were associated with the highest risks for some outcomes. As this is an observational study, it is susceptible to confounding by indication, channelling bias, and residual confounding, so differences in characteristics between patients prescribed different antidepressant drugs that could account for some of the associations between the drugs and the adverse outcomes may remain. Further research is needed to confirm these findings, but the risks and benefits of different antidepressants should be carefully evaluated when these drugs are prescribed to older people.

Association of changes in norepinephrine and serotonin transporter expression with the long-term behavioral effects of antidepressant drugs

Previous work has shown that repeated desipramine treatment causes downregulation of the norepinephrine transporter (NET) and persistent antidepressant-like effects on behavior, ie effects observed 2 days after discontinuation of drug treatment when acute effects are minimized. The present study examined whether this mechanism generalizes to other antidepressants and also is evident for the serotonin transporter (SERT). Treatment of rats for 14 days with 20 mg/kg per day protriptyline or 7.5 mg/kg per day sertraline reduced NET and SERT expression, respectively, in cerebral cortex and hippocampus; these treatments also induced a persistent antidepressant-like effect on forced-swim behavior. Increased serotonergic neurotransmission likely mediated the behavioral effect of sertraline, as it was blocked by inhibition of serotonin synthesis with p-chlorophenylalanine; a parallel effect was observed previously for desipramine and noradrenergic neurotransmission. Treatment with 20 mg/kg per day reboxetine for 42, but not 14, days reduced NET expression; antidepressant-like effects on behavior were observed for both treatment durations. Treatment for 14 days with 70 mg/kg per day venlafaxine, which inhibits both the NET and SERT, or 10 mg/kg per day phenelzine, a monoamine oxidase inhibitor, produced antidepressant-like effects on behavior without altering NET or SERT expression. For all drugs tested, reductions of NET and SERT protein were not accompanied by reduced NET or SERT mRNA in locus coeruleus or dorsal raphe nucleus, respectively. Overall, the present results suggest an important, though not universal, role for NET and SERT regulation in the long-term behavioral effects of antidepressants. Understanding the mechanisms underlying transporter regulation in vivo may suggest novel targets for the development of antidepressant drugs.

Selective serotonin reuptake inhibitors: a review of its effects on intraocular pressure

The increase in serotonin (5-HT) neurotransmission is considered to be one of the most efficacious medical approach to depression and its related disorders. The selective serotonin reuptake inhibitors (SSRIs) represent the most widely antidepressive drugs utilized in the medical treatment of depressed patients. Currently available SSRIs include fluoxetine, sertraline, paroxetine, fluvoxamine, citalopram and escitalopram. The primary SSRIs pharmacological action's mechanism consists in the presynaptic inhibition on the serotonin reuptake, with an increased availability of this amine into the synaptic cleft. Serotonin produces its effects as a consequence of interactions with appropriate receptors. Seven distinct families of 5-HT receptors have been identified (5-HT(1) to 5-HT(7)), and subpopulations have been described for several of these. The interaction between serotonin and post-synaptic receptors mediates a wide range of functions. The SSRIs have a very favorable safety profile, although clinical signs of several unexpected pathologic events are often misdiagnosed, in particular, those regarding the eye. In all cases reported in the literature the angle-closure glaucoma represents the most important SSRIs-related ocular adverse event. Thus, it is not quite hazardous to hypothesize that also the other reported and unspecified visual disturbances could be attributed - at least in some cases - to IOP modifications. The knowledge of SSRIs individual tolerability, angle-closure predisposition and critical IOP could be important goals able to avoid further and more dangerous ocular side effects.

A comparison of the chronic treatment effects of venlafaxine and other antidepressants on serotonin and norepinephrine transporters

BACKGROUND

Venlafaxine blocks both serotonin and norepinephrine transporters (SERT and NET), with higher affinity for SERT. Serotonergic effects occur with lower doses, whereas both serotonergic and noradrenergic effects occur with higher doses of venlafaxine. Chronic treatment of rats with selective serotonin reuptake inhibitors decreases SERT binding sites, whereas similar treatment with selective norepinephrine reuptake inhibitors decreases NET binding sites. We hypothesized that venlafaxine would affect monoamine transporters dose-dependently, with low doses causing selective reduction of SERT binding sites and higher doses reducing both SERT and NET binding sites.

METHODS

Rats were treated for 21 days with a low (15 mg/kg/day) or high (70 mg/kg/day) dose of venlafaxine, vehicle, or other antidepressants. The SERT and NET density was determined by quantitative autoradiography.

RESULTS

Neither dose of venlafaxine nor amitriptyline reduced binding to either the SERT or NET. In rats with noradrenergic terminals destroyed by 6-hydroxydopamine, venlafaxine still failed to reduce SERT binding. Also, rats treated simultaneously with sertraline plus desipramine exhibited reductions in both SERT and NET binding.

CONCLUSIONS

Chronic venlafaxine treatment affected SERT and NET binding differently from paroxetine or desipramine. The inability of venlafaxine to reduce SERT or NET binding sites is not due to its dual uptake inhibiting properties.

Poststroke Depression in Elderly Patients

Advanced practice nurses within acute care settings are responsible for providing healthcare to a rapidly expanding population of elderly patients. Medical advances have contributed to the longevity of the American population, resulting in an increase in age-related disease that can lead to depression. It is important for acute care nurses to become familiar with the various classes of antidepressant medications and the implications for their use.

Evidence-based treatment of mood disorders

Currently, mental health care is seeking parity with medical health care for the first time. The readers of this article are informed, globally aware, expert clinicians. They have access to the latest resources for diagnostics and clinical guidelines for managing mental health problems. They can incorporate their use of self as a therapeutic agent to teach, listen, and negotiate effectively with patients and their families for optimal outcomes in treating the whole person, mind, body, emotions, and spirit. Advanced practice psychiatric mental health nurses are able to move with the changes in mental health care [7,33,35].

Sertraline: a review of its use in the management of major depressive disorder in elderly patients

Sertraline is a selective serotonin reuptake inhibitor (SSRI) with well established antidepressant and anxiolytic activity. Results from several well designed trials show that sertraline (50 to 200 mg/day) is effective in the treatment of major depressive disorder in elderly patients (> or =60 years of age). Primary endpoints in most studies included the Hamilton Depression Rating Scale (HDRS), Clinical Global Impression (CGI) score and the Montgomery-Asberg Depression Rating Scale (MADRS). Sertraline was significantly more effective than placebo, and was as effective as fluoxetine, nortriptyline and imipramine in elderly patients. During one trial, amitriptyline was significantly more effective than sertraline [mean reduction from baseline on one of six primary outcomes (HDRS)], although no quantitative data were provided. Subgroup analysis of data from a randomised, double-blind trial in elderly patients with major depressive disorder suggests that vascular morbidity, diabetes mellitus or arthritis does not affect the antidepressant effect of sertraline. Secondary endpoints from these clinical trials suggest that sertraline has significant benefits over nortriptyline in terms of quality of life. In addition, significant differences favouring sertraline in comparison with nortriptyline and fluoxetine have been recorded for a number of cognitive functioning parameters. Sertraline is generally well tolerated in elderly patients with major depressive disorder, and lacks the marked anticholinergic effects that characterise the adverse event profiles of tricyclic antidepressants (TCAs). The most frequently reported adverse events in patients aged > or =60 years with major depressive disorder receiving sertraline 50 to 150 mg/day were dry mouth, headache, diarrhoea, nausea, insomnia, somnolence, constipation, dizziness, sweating and taste abnormalities. The tolerability profile of sertraline is generally similar in younger and elderly patients. Sertraline has a low potential for drug interactions at the level of the cytochrome P450 enzyme system. In addition, no dosage adjustments are warranted for elderly patients solely based on age.

CONCLUSION

Sertraline is an effective and well tolerated antidepressant for the treatment of major depressive disorder in patients aged > or =60 years. Since elderly patients are particularly prone to the anticholinergic effects of TCAs as a class, SSRIs such as sertraline are likely to be a better choice for the treatment of major depressive disorder in this age group. In addition, sertraline may have advantages over the SSRIs paroxetine, fluoxetine and fluvoxamine in elderly patients because of the drug's comparatively low potential for drug interactions, which is of importance in patient groups such as the elderly who are likely to receive more than one drug regimen.

A fresh look at management of depression. How to choose and use the newer antidepressant drugs

Depression is perhaps the most common medical condition seen by primary care physicians today, and rapidly evolving drug therapy for depression can present management challenges. Fortunately, most of the newer medications are effective, carry few risks, and have manageable side effects. Accurate diagnosis remains the focal point of effective patient care.

Drug and ECT treatment of depression in the elderly, 1996-2001: a literature review

A computer-based literature search of all antidepressant and electroconvulsive therapy (ECT) treatment studies published between 1995 and September 2001 was conducted. In addition, a review of published chapters, review articles, and metaanalyses was also conducted. Articles were categorized into those reporting comparative studies, those in which the therapeutic agent was not compared with another, articles about ECT, and review articles. These recent publications support the conclusions from prior reviews that antidepressants and ECT are effective and safe treatments for depressed elderly patients. Differences in efficacy and side effects appear to be slight among the various types of antidepressants. Research studies of depressed elderly increased markedly since 1995 compared with all previous years although more studies are still necessary.

Clinically significant drug interactions with antidepressants in the elderly

Pharmacological treatment of depression in old age is associated with an increased risk of adverse pharmacokinetic and pharmacodynamic drug interactions. Elderly patients may have multiple disease states and, therefore, may require a variety of other drugs. In addition to polypharmacy, other factors such as age-related physiological changes, diseases, genetic constitution and diet may alter drug response and, therefore, predispose elderly patients to adverse effects and drug interactions. Antidepressant drugs currently available differ in their potential for drug interactions. In general, older compounds, such as tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs), have a higher potential for interactions than newer compounds, such as selective serotonin reuptake inhibitors (SSRIs) and other relatively novel agents with a more specific mechanism of action. In particular, TCAs and MAOIs are associated with clinically significant pharmacodynamic interactions with many medications frequently prescribed to elderly patients. Moreover, TCAs may be susceptible to pharmacokinetic interactions when given in combination with inhibitors or inducers of the cytochrome P450 (CYP) isoenzymes involved in their metabolism. Because of a more selective mechanism of action, newer antidepressants have a low potential for pharmacodynamic drug interactions. However, the possibility of the serotonin syndrome should be taken into account when drugs affecting serotonergic transmission, such as SSRIs, venlafaxine or nefazodone, are coadministered with other serotonergic agents. Newer agents have a differential potential for pharmacokinetic interactions because of their selective effects on CYP isoenzymes. Within the group of SSRIs, fluoxetine and paroxetine are potent inhibitors of CYP2D6, while fluvoxamine predominantly affects CYP1A2 and CYP2C19 activity. Therefore, these agents should be closely monitored or avoided in elderly patients treated with substrates of these isoforms, especially those with a narrow therapeutic index. On the other hand, citalopram and sertraline have a low inhibitory activity on different drug metabolising enzymes and appear particularly suitable in an elderly population. Among other newer antidepressants, nefazodone is a potent inhibitor of CYP3A4 and its combination with substrates of this isoform should be avoided.

Discovery, innovation and the cyclical nature of the pharmaceutical business

Unlike many recent articles, which paint the future of the pharmaceutical industry in gloomy colours, this article provides an optimistic outlook. It explores the foundations on which the pharmaceutical industry has based its outstanding successes. Case studies of important drug classes underpin the arguments made and provide the basis for the authors' argument that recent technological breakthroughs and the unravelling of the human genome will provide a new wave of high quality targets (substrate) on which the industry can build. The article suggests that in a conducive environment that understands the benefits that pharmaceuticals provide to healthcare, those players who can base their innovation on a sufficient scale and from a large capital base will reshape the industry.

Nortriptyline in geriatric depression resistant to serotonin reuptake inhibitors: case series

Research on treatment-resistant depression in the elderly has been limited, and recommendations for clinical management have often been extrapolated from studies using nongeriatric patients. This report describes a series of 10 elderly patients with refractory depression who were treated with nortriptyline after failing to respond to an adequate trial of a serotonin reuptake inhibitor. Seven (70%) of the patients responded to the addition or substitution of nortriptyline. All seven of the responders have remained on nortriptyline for maintenance therapy, none of whom have experienced recurrence of their depression after an average treatment duration of 1 year. Response to nortriptyline occurred in about 4 weeks in most patients. The mean daily dose of nortriptyline was 54 mg, and the mean plasma level was 97 ng/mL. Minor side effects occurred in three patients. No patients developed significant electrocardiogram changes. Nortriptyline, possibly due to its different mechanism of action, may be effective as either an adjunctive or replacement antidepressant in some cases of geriatric depression that are resistant to serotonin reuptake inhibitors.