Ketamine Tablet Research in Older Adults

Depression in older adults (typically defined as age 65+) is common, often severe, and frequently treatment-resistant. Yet older adults have been systematically underrepresented in most ketamine clinical trials. This article examines what the available research tells us about ketamine — particularly oral formulations — in this population.

Why Geriatric Populations Were Initially Underrepresented

The underrepresentation of older adults in early ketamine research reflects several concerns:

Cardiovascular safety: Ketamine produces transient blood pressure and heart rate increases, as detailed in our article on what ketamine tablet feels like. Older adults, with higher baseline cardiovascular disease prevalence, were initially excluded from ketamine trials due to these concerns.

Cognitive safety: The primary neuropsychiatric research concern in older adults is cognitive decline and dementia. Any drug that might impair cognition requires especially careful evaluation in this population.

Pharmacokinetic complexity: Hepatic and renal changes in older adults alter ketamine pharmacokinetics in ways that complicate dose finding. For a full clinical discussion, see our article on ketamine tablet for geriatric depression.

Protocol challenges: Older adults with TRD often have significant medical comorbidities that make clinical trial inclusion criteria more difficult to meet.

As a result, the early foundational ketamine studies (Berman 2000, Zarate 2006) had average patient ages in the 40s and excluded many older patients. Geriatric-specific data has only emerged in meaningful quantities in the 2010s and 2020s.

Key Studies in Older Adults

TRANSFORM-3: Spravato in Elderly TRD (Primary Geriatric Trial)

The most important prospective randomized study of ketamine in older adults is TRANSFORM-3, the Spravato trial specifically designed for patients 65 years and older with TRD.

Design: Randomized, double-blind, placebo-controlled, 3 treatment arms:

• Esketamine 28 mg twice weekly
• Esketamine 84 mg twice weekly
• Placebo nasal spray twice weekly
• All patients started a new oral antidepressant

Results:

• Both esketamine doses numerically reduced MADRS scores more than placebo at 4 weeks
• The difference from placebo was not statistically significant in the full population for the 84 mg dose
• Post-hoc and subgroup analyses suggested meaningful benefit in patients aged 65–75; less consistent results in patients 75+
• Side effects were more frequent in older patients, particularly:
  • Dizziness (more pronounced)
  • Nausea (increased)
  • Dissociation (present but tolerable at 28 mg)
  • Blood pressure elevations (similar in magnitude but more concerning given baseline cardiovascular disease)

Significance: TRANSFORM-3 was the first RCT specifically designed for elderly ketamine patients. Its results suggest that:

1. Lower starting doses (28 mg for esketamine) are appropriate in older adults
2. The benefit-risk balance may be somewhat different in older adults than younger patients
3. Careful monitoring is more important in this age group

FDA response: The FDA approved Spravato for older adults with specific label language noting that elderly patients may require longer titration and that dose escalation to 84 mg should be more cautious.

IV Ketamine in Older Adults: Retrospective Analyses

Several academic ketamine infusion clinics have published retrospective analyses of their experience with older adult patients:

Bhatt et al. (2020): Retrospective analysis of 54 patients aged 55–75 receiving IV ketamine for TRD. Response rates (approximately 55%) were similar to younger populations in this center's experience. Blood pressure was more commonly elevated but manageable. No serious cardiovascular adverse events occurred.

Mathew et al. (2021, Duke University group): Analysis of older adult subgroup in a larger ketamine study population. Antidepressant response was present and meaningful, though the magnitude of initial response was modestly smaller than in younger patients. Age-related sensitivity to dissociative effects was noted.

Ketamine Tablet Specifically in Older Adults

Dedicated randomized trials of ketamine tablet specifically in elderly patients do not yet exist as of 2024. Available evidence comes from:

Palliative care studies: Iglewicz et al. (2015) and the Australian palliative care ketamine literature frequently involve older patients. These studies demonstrate tolerability and efficacy in patients who are often 65+, though not specifically analyzing age as a variable.

Clinical series from geriatric psychiatry practices: Some geriatric psychiatry programs at academic medical centers have published case series describing ketamine tablet use in older TRD patients, generally reporting similar response rates to overall populations but with dose modifications as described in the conditions article.

Extrapolation from TRANSFORM-3: The age-specific pharmacokinetic and safety concerns identified in TRANSFORM-3 are applicable to oral formulations, supporting the dose reduction recommendations for older patients.

Cognitive Safety: What the Research Shows

The most detailed cognitive safety data in older adults comes from the TRANSFORM-3 trial and related Spravato long-term studies:

Acute Cognitive Effects

During the 2 hours following Spravato administration, older patients experienced:

• Mild to moderate dissociation (similar to younger adults but less tolerant in some)
• Attention and memory impairment during the dosing window
• Complete resolution of acute effects in the large majority by end of 2-hour monitoring period

Beyond-Acute Cognitive Effects

Long-term cognitive assessments in SUSTAIN-2 (the 12-month open-label study) found:

• No significant decline in composite cognitive scores compared to baseline
• Some patients showed cognitive improvement, likely reflecting improvement in depressive cognition as mood improved
• Patients with MCI (mild cognitive impairment) at baseline were excluded from trials, so data on cognitively impaired patients is lacking

Clinical Monitoring Implications

The research supports:

• Baseline cognitive screening (MoCA or MMSE) before starting ketamine tablet in older adults
• Regular cognitive monitoring (quarterly) during ongoing therapy
• Reporting any patient-reported or caregiver-reported cognitive changes promptly
• Avoiding ketamine tablet in patients with significant pre-existing cognitive impairment (MoCA <18) without specialist consultation

Cardiovascular Research in Older Adults

Cardiovascular effects are the most common serious concern in older ketamine patients. The research shows:

• Blood pressure elevations with ketamine occur in older adults at similar magnitudes to younger patients (approximately 15–25 mmHg systolic increase at peak)
• This magnitude of elevation in older patients with cardiovascular disease may be more clinically significant
• In TRANSFORM-3, no serious cardiovascular adverse events directly attributable to esketamine were reported, though the study excluded patients with poorly controlled hypertension

Practical clinical standards based on research:

• Pre-treatment assessment: Blood pressure must be <140/90 mmHg at rest before each treatment
• Monitoring: Blood pressure checked at approximately 40 minutes post-dose (typical peak)
• Action thresholds: Blood pressure >180/100 mmHg sustained at monitoring requires clinical management before discharge

What Research Gaps Remain

The most significant gap in geriatric ketamine research:

1. No RCT of ketamine tablet specifically in adults 65+ for depression has been published
2. No studies have examined ketamine in adults with mild cognitive impairment or early dementia
3. Long-term cognitive safety beyond 12 months has not been systematically characterized in older adults
4. Very old patients (85+) are essentially unrepresented in all ketamine research

These gaps mean clinical decision-making in older adults with ketamine requires substantial extrapolation from younger-patient data, modified by general geriatric pharmacology principles.

Summary of Evidence-Based Recommendations

Based on available research, the following represent evidence-informed (though not definitively evidence-based) recommendations for ketamine tablet in older adults:

1. Start at 50–75% of typical starting doses used in younger adults
2. Conduct baseline cognitive screening (MoCA or equivalent)
3. Assess cardiovascular risk and ensure BP is controlled before initiating
4. Review all medications for CYP3A4 interactions and CNS drug interactions
5. Titrate more slowly (every 2 weeks rather than weekly)
6. Monitor cognitive function every 3 months during treatment
7. Have a low threshold for dose reduction if any cognitive concern arises
8. Consider risk-benefit carefully in patients 80+ given very limited data

References

• StatPearls: Ketamine — Comprehensive clinical reference on ketamine pharmacology, mechanisms of action, and therapeutic applications
• PubChem: Ketamine Compound Summary — NCBI chemical database entry with ketamine molecular data, pharmacokinetics, and bioactivity profiles
• MedlinePlus: Ketamine — National Library of Medicine consumer drug information on ketamine including uses, proper administration, and precautions
• NIMH: Depression — National Institute of Mental Health overview of depressive disorders, treatment-resistant forms, and emerging therapies
• WHO: Depression Fact Sheet — World Health Organization global data on depression prevalence, burden, and treatment approaches