Optimal dosing of antidepressant drugs

For what indications are antidepressants being used in adults in Colombia?

INTRODUCTION

Antidepressants are useful in the pharmacological treatment of different depressive and anxiety disorders, as well as being potentially useful in other indications. The aim of the study was to determine the indications for which antidepressants are being prescribed in patients over 18 years of age registered with the Colombian Health System.

METHODS

Retrospective study with data from patients over 18 years old, of either sex, registered with the Colombian Health System, who are prescribed antidepressants. Medical records were reviewed, looking for indications approved and not approved by regulatory agencies. Patients were identified randomly, as well as the sociodemographic, clinical and pharmacological variables that could be associated with prescriptions for unapproved indications.

RESULTS

351 patients were evaluated, with a mean age of 60.4 ± 15.3 years, of whom 72.6% were women. They were attended in 34 cities, with prescriptions mainly by general practitioners (n = 276; 78.6%), and psychiatrists (n = 42; 12.0%). Selective serotonin reuptake inhibitors were the most widely prescribed antidepressants (n = 204; 58.1%), followed by atypicals (n = 76; 21.7%). The most frequent indications were for depression (n = 169; 48.1%), anxiety (n = 48; 13.7%), pain (n = 22; 6.3%) and sleep disorders (n = 17; 4.8%). A total of 188 prescriptions (53.6%) were made for approved indications, and the remaining 163 (46.4%) were classified as unapproved.

CONCLUSIONS

Antidepressants are being prescribed for the treatment of depression, anxiety, pain and sleep disorders, especially in older adult women, but almost half of the formulations were for unapproved indications.

Metabolizing status of CYP2C19 in response and side effects to medications for depression: Results from a naturalistic study

Major depressive disorder (MDD) is one of the leading causes of disability worldwide. Polymorphisms in cytochrome P450 genes (CYP450) were demonstrated to play a significant role in antidepressant response and side effects, but their effect in real-world clinical practice is poorly known. We determined the metabolic status of CYP2C19 based on the combination of *1, *2, *3 and *17 alleles extracted from genome-wide data in 1239 patients with MDD, pharmacologically treated in a naturalistic setting. Symptom improvement and side effects were assessed using the Montgomery and Åsberg Depression Rating Scale and the Udvalg for Kliniske Undersøgelse scale, respectively. We tested if symptom improvement, response and side effects were associated with CYP2C19 metabolic status adjusting for potential confounders. We considered patients treated with drugs for depression having CYP2C19 genotyping recommended by guidelines (T1 Drugs); secondarily, with all psychotropic drugs having CYP2C19 as relevant metabolic path (T2 Drugs). In the group treated with T1 drugs (n = 540), poor metabolizers (PMs) showed higher response and higher symptom improvement compared to normal metabolizers (p = 0.023 and p = 0.009, respectively), but also higher risk of autonomic and neurological side effects (p = 0.022 and p = 0.022 respectively). In patients treated with T2 drugs (n = 801), similar results were found. No associations between metabolizer status and other types of side effects were found (psychic and other side effects). Our study suggests potential advantages of CYP2C19 pharmacogenetic testing to guide treatment prescription, that may not be limited to the drugs currently recommended by guidelines.

For What Indications are Antidepressants Being Used in Adults in Colombia?

INTRODUCTION

Antidepressants are useful in the pharmacological treatment of different depressive and anxiety disorders, as well as being potentially useful in other indications. The aim of the study was to determine the indications for which antidepressants are being prescribed in patients over 18 years of age registered with the Colombian Health System.

METHODS

Retrospective study with data from patients over 18 years old, of either sex, registered with the Colombian Health System, who are prescribed antidepressants. Medical records were reviewed, looking for indications approved and not approved by regulatory agencies. Patients were identified randomly, as well as the sociodemographic, clinical and pharmacological variables that could be associated with prescriptions for unapproved indications.

RESULTS

351 patients were evaluated, with a mean age of 60.4±15.3 years, of whom 72.6% were women. They were attended in 34 cities, with prescriptions mainly by general practitioners (n=276; 78.6%), and psychiatrists (n=42; 12.0%). Selective serotonin reuptake inhibitors were the most widely prescribed antidepressants (n=204; 58.1%), followed by atypicals (n=76; 21.7%). The most frequent indications were for depression (n=169; 48.1%), anxiety (n=48; 13.7%), pain (n=22; 6.3%) and sleep disorders (n=17; 4.8%). A total of 188 prescriptions (53.6%) were made for approved indications, and the remaining 163 (46.4%) were classified as unapproved.

CONCLUSIONS

Antidepressants are being prescribed for the treatment of depression, anxiety, pain and sleep disorders, especially in older adult women, but almost half of the formulations were for unapproved indications.

No benefit from flexible titration above minimum licensed dose in prescribing antidepressants for major depression: systematic review

BACKGROUND

In fixed-dose antidepressant trials, the lower range of the licensed dose achieves the optimal balance between efficacy and tolerability. Whether flexible upward titration while side-effects permit provides additional benefits is unknown.

METHODS

We did a systematic review of placebo-controlled randomized trials that examined selective serotonin reuptake inhibitors (SSRIs), venlafaxine or mirtazapine in the acute treatment of major depression. Our primary outcome was response, defined as 50% or greater reduction in depression severity. Secondary outcomes included drop-outs due to adverse effects and drop-outs for any reason. We conducted random-effects meta-analyses to calculate the ratios of odds ratios (RORs) between trials comparing the flexible dose titrating above the minimum licensed dose against placebo and those comparing the fixed minimum licensed dose against placebo.

RESULTS

We included 123 published and unpublished randomized controlled trials (29 420 participants). There was no evidence supporting efficacy of the flexible dosing over the fixed low dose of SSRIs (ROR 0.96, 95% CI: 0.73 to 1.25), venlafaxine (1.24, 0.96 to 1.60) or mirtazapine (0.77, 0.33 to 1.78). No important differences were noted for tolerability or for any subgroup analyses except the superior efficacy of venlafaxine flexible dosing between 75 and 150 mg over the fixed 75 mg (1.30, 1.02 to 1.65).

CONCLUSION

There was no evidence to support added value in terms of efficacy, tolerability or acceptability of flexibly titrating up the dosage over the minimum licensed dose of SSRIs or mirtazapine. For venlafaxine, increased efficacy can be expected by flexibly titrating up to 150 mg.