Tolerability of combined treatment with lithium and paroxetine: 19 cases treated under open conditions

Patient perspectives of lithium and quetiapine augmentation treatment in treatment-resistant depression: A qualitative assessment

BACKGROUND

Treatment-resistant depression (TRD) has a profound cost to patients and healthcare services worldwide. Pharmacological augmentation is one therapeutic option for TRD, with lithium and quetiapine currently recommended as first-line agents. Patient opinions about pharmacological augmentation may affect treatment outcomes, yet these have not been systematically explored.

AIMS

This study aimed to qualitatively assess patient experiences of lithium and quetiapine augmentation.

METHODS

Semi-structured interviews were conducted with 32 patients from the ongoing lithium versus quetiapine open-label trial comparing these augmentation agents in patients with TRD. Interviews were audio recorded, transcribed and a thematic analysis was used to assess patient opinions of each agent.

RESULTS

Four main themes were generated from the thematic analysis: 'Initial concerns', 'Experience of side effects', 'Perception of treatment efficacy' and 'Positive perception of treatment monitoring'. Patient accounts indicated a predominantly positive experience of lithium and quetiapine augmentation. Greater apprehension about side effects was reported for lithium prior to treatment initiation, but greater experience of negative side effects was reported for quetiapine. Clinical monitoring was perceived positively.

CONCLUSION

Patient accounts suggested treatment augmentation with lithium or quetiapine was acceptable and helpful for most patients. However, anticipation and experiences of adverse side effects may prevent some patients from benefitting from these treatments.

The impact of CYP2D6 mediated drug-drug interaction: a systematic review on a combination of metoprolol and paroxetine/fluoxetine

AIM

Metoprolol (a CYP2D6 substrate) is often co-prescribed with paroxetine/fluoxetine (a CYP2D6 inhibitor) because the clinical relevance of this drug-drug interaction (DDI) is still unclear. This review aimed to systematically evaluate the available evidence and quantify the clinical impact of the DDI.

METHOD

Pubmed, Web of Science, Cochrane Library and Embase were searched for studies reporting on the effect of the DDI among adults published until April 2018. Data on pharmacokinetics, pharmacodynamics and clinical outcomes from experimental, observational and case report studies were retrieved. The protocol of this study was registered in PROSPERO (CRD42018093087).

RESULTS

We found nine eligible articles that consisted of four experimental and two observational studies as well as three case reports. Experimental studies reported that paroxetine increased the AUC of metoprolol three to five times, and significantly decreased systolic blood pressure and heart rate of patients. Case reports concerned bradycardia and atrioventricular block due to the DDI. Results from observational studies were conflicting. A cohort study indicated that the DDI was significantly associated with the incidence of early discontinuation of metoprolol as an indicator of the emergence of metoprolol-related side effects. In a case-control study, the DDI was not significantly associated with bradycardia.

CONCLUSION

Despite the contradictory conclusions from the current literature, the majority of studies suggest that the DDI can lead to adverse clinical consequences. Since alternative antidepressants and beta-blockers with comparable efficacy are available, such DDIs can be avoided. Nonetheless, if prescribing the combination is unavoidable, a dose adjustment or close monitoring of the metoprolol-related side effects is necessary.

Changes in quantitatively assessed tremor during treatment of major depression with lithium augmented by paroxetine or amitriptyline

Tremor is a relatively frequent side effect of lithium and of antidepressants with serotonergic properties. It can be expected that combinations of lithium (which is itself serotonergic) with such antidepressants will enhance not only efficacy, but also the incidence of side effects, including tremor. To quantitatively monitor the effect of antidepressant augmentation of ongoing lithium therapy on tremor, lithium-maintained patients with a breakthrough episode of major depression were randomly assigned under double-blind conditions to receive paroxetine 20 mg/day (N = 14) or amitriptyline 75 mg/day (N = 17). The initial dosages could be increased after 2 weeks to 40 mg/day and 150 mg/day, respectively, and the patients were treated for 6 weeks. Tremor activity was assessed weekly, quantitatively by accelerometry and qualitatively with the Dosage Record and Treatment Emergent Symptom Scale. Statistical analysis detected no significant difference between the treatment groups with respect to changes in mean tremor activity relative to baseline. However, analysis of the pooled data showed that tremor increased significantly during the course of combined lithium and antidepressant therapy, with the greatest increments occurring independent of dosage approximately 3 weeks after initiation of combination treatment. Although the mean tremor activity subsided toward the end of treatment, tremor activity on the whole was still significantly greater after 6 weeks of combined lithium and antidepressant treatment than at the start of combination therapy. Increased tremor was not associated with decreased medication compliance, and no patient discontinued treatment because of increased tremor. Tremor frequency was not affected by the study treatments.

Paroxetine and amitriptyline augmentation of lithium in the treatment of major depression: a double-blind study

To study the efficacy and safety of antidepressant augmentation of ongoing lithium therapy, lithium-maintained patients suffering from an breakthrough episode of major depression were randomly assigned under double-blind conditions to receive paroxetine 20 mg/day (N = 19) or amitriptyline 75 mg/day (N = 23). The initial dosages could be increased after 2 weeks to 40 mg/day and 150 mg/day, respectively, and the patients were treated for a total of 6 weeks. Efficacy was assessed weekly with the 21-item Hamilton Rating Scale for Depression (HAM-D) and the Clinical Global Impression Scale (CGI), and safety was assessed with the Dosage Record and Treatment Emergent Symptom Scale. After 4 weeks, a significantly greater proportion of patients in the paroxetine group had achieved a 50% reduction in baseline HAM-D scores, and the mean improvement in CGI severity of illness was significantly greater in the paroxetine group at weeks 3 and 5. The type and number of emergent events occurring during study treatment corresponded to the known side effect profiles of paroxetine and amitriptyline. Serum lithium levels were not affected by either antidepressant. The authors proposed that the more rapid improvement demonstrated by the group receiving the combination of lithium and paroxetine may be due to the synergistic serotonergic effects of these two medications.

Combination therapy with nefazodone and lithium: Safety and tolerability in fourteen patients

Fourteen patients with major depression, resistant to previous pharmacotherapies, were treated by the addition of lithium (target range 0.6-0.8 mmol/l) to nefazodone (≥400 mg/day) and were prospectively monitored for 6 weeks to assess safety and tolerability. There were 42 emergent adverse events-most commonly headache, nausea, gastro-intestinal disturbances, tremor, polyuria/polydipsia, dry mouth and tiredness. Information on ten additional patients receiving combined treatment with lithium and nefazodone was collected by retrospective chart review, and it was found that similar adverse events (tremor, dry mouth and tiredness) had occurred in these patients. We conclude that when lithium is added to nefazodone, new adverse events do occur, but that the treatment is safe and tolerable.

Paroxetine. An update of its pharmacology and therapeutic use in depression and a review of its use in other disorders

Paroxetine is a potent and selective inhibitor of the neuronal reuptake of serotonin (5-hydroxytryptamine; 5-HT), which was previously reviewed as an antidepressant in Drugs in 1991. Since then, more comparative trials with other antidepressants have become available, and its use in the elderly and as long term maintenance therapy has been investigated. Paroxetine has also been studied in several other disorders with a presumed serotonergic component, primarily obsessive compulsive disorder (OCD) and panic disorder. In short term clinical trials in patients with depression, paroxetine produced clinical improvements that were significantly greater than those with placebo and similar to those achieved with other agents including tricyclic antidepressants (TCAs), maprotiline, nefazodone and the selective serotonin reuptake inhibitors (SSRIs) fluoxetine, fluvoxamine and sertraline. Long term data suggest that paroxetine is effective in preventing relapse or recurrence of depression in patients treated for up to 1 year. In the elderly, the overall efficacy of paroxetine was at least as good as that of comparator agents. In short term clinical trials involving patients with OCD or panic disorder, paroxetine was significantly more effective than placebo and of similar efficacy to clomipramine. Limited long term data show that paroxetine is effective in maintaining a therapeutic response over periods of 1 year (OCD) and up to 6 months (panic disorder). Preliminary data suggest that paroxetine has potential in the treatment of social phobia, premenstrual dysphoric disorder and chronic headache. Like the other SSRIs, paroxetine is better tolerated than the TCAs, causing few anticholinergic adverse effects. The most commonly reported adverse event associated with paroxetine treatment is nausea, although this is generally mild and subsides with continued use. Fewer withdrawals from treatment due to adverse effects occurred with paroxetine treatment than with TCAs. The adverse events profile of paroxetine appears to be broadly similar to that of other SSRIs, although data from comparative trials are limited. Serious adverse effects associated with paroxetine are very rare. In conclusion, paroxetine is effective and well tolerated, and suitable as first-line therapy for depression. It also appears to be a useful alternative to other available agents for the treatment of patients with OCD or panic disorder.

A protocol for the pharmacologic treatment of major depression. A field test of a potential prototype

BACKGROUND

Much attention is being given to developing clinical practice guidelines for management of mental health disorders. The aim of this study was to field test a prototype protocol for the pharmacologic treatment of Major Depression.

METHOD

The protocol consisted of four, six week, treatment phases with critical choices in therapy defined by scores on the MADRS (Montgomery Asberg Depression Rating Scale). Observational data as collected on the behaviour of the protocol in terms of relevance, acceptability, ease of use and effectiveness.

RESULTS

Effectiveness of the protocol was good for those patients who were retained within it, with three quarters of them attaining remission. However more than half of all patients dropped out-non attendance and adverse events being the most common reasons for this.

CONCLUSION

The protocol for the treatment of Major Depression appeared relevant, easy to use and potentially effective.

LIMITATION

Problems with non-adherence by both doctors and patients posed major challenges to the protocol's design. Such difficulties demonstrate the need to field test any proposed design as preconceptions about a protocol's performance may be misplaced.

CLINICAL RELEVANCE

The protocol tested represents progress towards the goal of developing optimal strategies for the use of pharmacotherapeutic agents in the treatment of depression.

A review of the use of augmentation therapy for the treatment of resistant depression: implications for the clinician

OBJECTIVE

To critically review the literature on augmentation therapy in resistant depression in order to assist the clinician to make a reasoned choice. Augmentation therapy is defined as the addition of a second agent to an existing antidepressant regimen with the aim of achieving improved clinical response.

METHOD

The available literature which related specifically to currently popular augmentation strategies in treatment resistant depression for the past 20 years was examined. The scientific evidence supporting the efficacy of these regimens and their safety was reviewed.

RESULTS

Considerable research on lithium augmentation has been undertaken, and on triiodothyronine augmentation to a lesser degree. A number of other drugs have been trialed as augmentation agents with claims of success; however, most of the evidence supporting these agents is anecdotal and in the form of case reports. There are very few well-performed double-blind placebo-controlled studies of augmentation therapy.

CONCLUSIONS

Because of possible complex pharmacodynamic and pharmacokinetic interactions, augmentation therapy is not without its potential complications. Lithium augmentation of tricyclic antidepressants can be recommended as a safe and effective strategy and there is a body of scientific evidence supporting the addition of T3 as an effective augmentation agent. Recent research with pindolol augmentation of selective serotonin re-uptake inhibitors (SSRIs) is encouraging, but these findings require replication. There is no empirical evidence supporting buspirone, carbamazepine, sodium valproate, methylphenidate or amphetamine as effective augmentation agents, or that adding a tricyclic to a SSRI has usefulness in relieving depressive symptoms. There is a need for considerable research in this area, with more prospective well-controlled placebo studies.

A double-blind, placebo-controlled study of citalopram with and without lithium in the treatment of therapy-resistant depressive patients: a clinical, pharmacokinetic, and pharmacogenetic investigation

Sixty-nine depressive patients (DSM III criteria: 296.2, 296.3, 296.5, 300.4) were treated with 40 to 60 mg citalopram (CIT) daily for 4 weeks. Among them, 45 responded to treatment (improvement > 50% on the 21-item Hamilton Rating Scale for Depression [HAM-D]) and continued their treatment for another week before being released from the study. The 24 nonresponders were randomized and comedicated under double-blind conditions with lithium carbonate (Li) (2 x 400 mg/day) (CIT-Li group) or with placebo (CIT-Pl group) from days 29 to 35. For days 36 to 42, the patients of both subgroups were treated openly with Li (800 mg/day) in addition to the ongoing CIT treatment. On day 35, 6 of 10 patients responded to the CIT-Li combination, whereas 2 of 14 patients only responded to the CIT-Pl combination. This group difference reached significance (p < 0.05) on day 35 with lower HAM-D total scores in the CIT-Li group. No evidence was seen of a pharmacokinetic interaction between CIT and Li, and this combination was well tolerated. Patients were phenotyped with dextromethorphan and mephenytoin at baseline and at day 28. As evaluated at baseline, three patients (responders) were poor metabolizers of dextromethorphan and six patients (three responders and three nonresponders) of mephenytoin. On day 28, the ratio CIT/N-desmethylCIT (DCIT) in plasma was significantly higher in poor than in extensive metabolizers of mephenytoin (p = 0.0001), and there was a significant positive correlation between the metabolic ratio of dextromethorphan and the ratio DCIT/N-didesmethylCIT in plasma (p < 0.001). These findings illustrate the role of CYP2D6 and CYP2C19 in the metabolism of CIT. It can be concluded that Li addition to CIT is effective in patients not responding to CIT alone without any evidence of an accentuation or provocation of adverse events.

Safety and tolerability of combined treatment with moclobemide and SSRIs: a preliminary study of 19 patients

Nineteen major depressed patients, resistant to previous pharmacotherapies, were treated by the addition of moclobemide (up to 600 mg/day) to paroxetine or fluoxetine (20 mg/day) for 6 weeks in an open study to assess the adverse events and tolerability. There were 77 emergent events, insomnia, headache, nausea and dizziness being the most common. Many events were rated as severe. The high rate of adverse events suggests that there may be clinically significant interactions between moclobemide and SSRIs. However, the uncontrolled data on effectiveness is encouraging and the combination deserves further attention as a strategy for treating intractable major depression.