Add-On Antidepressant for Elderly Female on Celexa
Augment citalopram (Celexa) with bupropion (Wellbutrin) as the preferred add-on strategy for treatment-resistant depression in elderly patients. 1
Rationale for Bupropion Augmentation
Bupropion augmentation of SSRIs demonstrates equivalent efficacy to other augmentation strategies (such as buspirone) in achieving response and remission rates in patients who have not responded adequately to initial SSRI monotherapy. 1
Bupropion has significantly fewer discontinuation rates due to adverse events compared to buspirone augmentation (12.5% vs. 20.6%, p<0.001), making it better tolerated in clinical practice. 1
The activating properties of bupropion can counteract SSRI-induced sedation and may provide rapid improvement in energy levels, which is particularly beneficial in elderly patients with depression. 1
Bupropion lacks sexual side effects, addressing one of the most common adverse effects of SSRIs (weighted mean incidence of 40% with SSRIs), which can improve medication adherence. 1
Dosing Strategy for Elderly Patients
Start bupropion at 37.5 mg every morning, then increase by 37.5 mg every 3 days as tolerated. 1
Target dose is 150 mg twice daily (maximum 450 mg/day), though elderly patients may respond to lower doses. 1, 2
Administer the second dose before 3 p.m. to minimize risk of insomnia, which is a common side effect. 1
Critical Safety Considerations
Contraindicated in patients with seizure disorders or history of seizures, as bupropion lowers the seizure threshold. 1
Avoid in agitated patients, as bupropion's activating properties may worsen agitation. 1
Monitor for falls risk, as bupropion augmentation was associated with the highest rate of falls among augmentation strategies in elderly patients in the OPTIMUM trial. 2
Citalopram dose must not exceed 20 mg/day in patients over 60 years due to dose-dependent QT prolongation risk (FDA boxed warning). 1, 3
Alternative Augmentation Options
If Bupropion is Contraindicated:
Aripiprazole augmentation (up to 15 mg/day) shows equivalent efficacy to bupropion and may provide modest advantages in inhibitory control and cognitive function in elderly patients. 2
Aripiprazole demonstrated improved inhibitory control compared to bupropion augmentation in the Flanker test (p=0.0052), which may be relevant for elderly patients with cognitive concerns. 2
However, aripiprazole carries risks of extrapyramidal symptoms, metabolic effects, and sedation that require careful monitoring in elderly populations. 2
Lithium Augmentation:
Lithium can be used for augmentation at low doses (150-300 mg/day) targeting blood levels of 0.2-0.6 mEq/L, which are generally adequate for elderly patients. 1
Elderly patients are prone to neurotoxicity at higher lithium levels, necessitating conservative dosing and frequent monitoring. 1
Lithium augmentation showed no improvement in inhibitory control compared to switch strategies in elderly patients with treatment-resistant depression. 2
Why Not Switch Instead of Augment?
Switching from one SSRI to another (e.g., citalopram to sertraline, bupropion, or venlafaxine) shows no difference in response or remission rates compared to augmentation strategies. 1
Augmentation preserves any partial response already achieved with citalopram, whereas switching requires starting over with a new medication. 1
The STAR*D trial demonstrated similar efficacy between augmentation with bupropion or buspirone and switching to another antidepressant, but augmentation allows continuation of a partially effective medication. 1
Common Pitfalls to Avoid
Do not exceed citalopram 20 mg/day in patients over 60 years, as this violates FDA safety guidelines for QT prolongation. 1, 3
Do not combine bupropion with medications that lower seizure threshold or use in patients with eating disorders (increased seizure risk). 1
Do not assume cognitive decline is inevitable with antidepressant treatment—the OPTIMUM trial showed no significant differences in global cognitive function between various pharmacotherapy strategies over 10 weeks. 2
Do not overlook drug interactions: While citalopram has relatively low interaction potential, bupropion is metabolized by CYP2B6 and may interact with other medications. 4
Avoid combining multiple serotonergic agents without careful monitoring for serotonin syndrome risk. 4
Monitoring Parameters
Assess response at 6 weeks minimum, as at least six weeks of antidepressant treatment is recommended to achieve optimal therapeutic effect in elderly patients. 5
Monitor for falls, agitation, and sleep disturbances particularly in the first few weeks after adding bupropion. 2
Check ECG if citalopram dose approaches 20 mg/day or if patient has cardiac risk factors, given QT prolongation concerns. 1, 3
Evaluate for improvement in energy and motivation within the first 1-2 weeks, as bupropion may provide rapid improvement in these domains. 1