How should a 59‑year‑old with acute mental status change and disorganized thought process after a suspected gabapentin overdose, and no prior psychiatric history, be managed?

Management of Acute Mental Status Change Following Suspected Gabapentin Overdose

Provide immediate supportive care with airway protection and ventilatory support as needed, while simultaneously evaluating for co-ingestions—particularly opioids and benzodiazepines—which dramatically increase morbidity and mortality risk in gabapentin overdose. 1

Immediate Stabilization and Assessment

Airway and Breathing

• Establish and maintain airway patency; progress to endotracheal intubation if the patient cannot protect their airway, as gabapentin overdose commonly causes altered mental status, drowsiness, and lethargy that may compromise respiratory function. 1, 2
• Support oxygenation to prevent hypoxemia-related tissue injury; check oxygen saturation and provide supplemental oxygen only if hypoxic, as unnecessary oxygen can worsen confusion. 1

Circulation and Monitoring

• Treat hypotension with standard fluid resuscitation and vasopressors as indicated. 1
• Monitor for and manage cardiac dysrhythmias according to standard protocols, though these are uncommon in isolated gabapentin overdose. 1
• Check vital signs including temperature, as fever can worsen outcomes and may indicate concurrent infection. 3

Critical Co-Ingestion Assessment

• Always evaluate for co-ingestions, as these significantly increase morbidity and mortality risk—particularly opioids, benzodiazepines, and other CNS depressants. 1
• Administer naloxone immediately if opioid co-ingestion is suspected, regardless of gabapentin involvement. 1
• Review all current medications, especially sedative-hypnotics, anticholinergics, and other deliriogenic agents. 3

Delirium-Specific Evaluation

Structured Assessment

• Use the Confusion Assessment Method (CAM) to objectively diagnose delirium, as clinical gestalt alone misses the majority of cases. 4
• Document acute onset (hours-to-days), fluctuating course, inattention, and disorganized thinking—core features that differentiate delirium from dementia or primary psychiatric disorders. 4
• Assess every 8-12 hours (at least once per shift) as mental status fluctuates substantially throughout the day. 4

Identify Reversible Causes Beyond Gabapentin

• Check blood glucose immediately to rule out hypoglycemia as a reversible cause. 3
• Obtain complete blood count, comprehensive metabolic panel, urinalysis, and thyroid function tests guided by clinical evaluation. 4
• Assess for infection (urinary tract infection and pneumonia are the most frequent precipitants), metabolic disturbances (hyponatremia, hypoxia), and substance withdrawal (particularly alcohol). 4, 3
• Perform targeted neurological examination to identify focal deficits suggesting stroke or structural lesion. 3

Neuroimaging Decision Algorithm

When CT Head is Indicated

Obtain non-contrast CT head if any of the following are present: 5, 4

• Focal neurological deficits
• Recent head trauma or falls
• New-onset seizures
• Therapeutic anticoagulation or coagulopathy
• Signs of increased intracranial pressure
• Unexplained altered mental status despite initial workup

When CT Head is NOT Routinely Required

• CT is not needed for delirium cases with an identified clear precipitant (gabapentin overdose, infection, metabolic disturbance) and lacking focal neurological findings. 4
• In intoxicated patients, a period of clinical observation for symptomatic improvement is safe and prevents unnecessary CT scans in a large proportion of cases. 5

Second-Line Imaging

• Reserve MRI for when CT is unrevealing but suspicion remains for occult pathology such as small infarcts, encephalitis, or subtle subarachnoid hemorrhage. 5, 4

Gabapentin-Specific Management

Understanding Gabapentin Toxicity

• Gabapentin overdoses up to 49 grams have been reported with symptoms including double vision, slurred speech, drowsiness, lethargy, diarrhea, myoclonus, confusion, and hallucinations—all patients recovered with supportive care. 2
• In patients with renal impairment, gabapentin elimination half-life increases from 5-9 hours to 132 hours in dialysis patients, dramatically increasing toxicity risk. 6, 7
• Coma has been reported in patients with chronic renal failure treated with gabapentin, resolving with dialysis. 2

Hemodialysis Consideration

• Gabapentin can be removed by hemodialysis and may be indicated based on the patient's clinical state or in patients with significant renal impairment. 2
• Hemodialysis rapidly improves symptoms; in one case report, gabapentin concentration became undetectable and symptoms (hearing loss, myoclonus, confusion) resolved within 4 days following a single dialysis session. 6
• Contact the regional poison control center (1-800-222-1222) for expert toxicology guidance on whether hemodialysis is indicated in your specific case. 1, 2

Non-Pharmacological Delirium Management

Environmental Modifications (First-Line)

• Provide appropriate lighting, visible clocks and calendars, clear signage, and minimize sensory overload. 3
• Ensure continuity of care by avoiding unnecessary room changes and maintaining consistent caregivers. 3
• Facilitate regular family visits to help with reorientation and provide familiar presence. 3
• Implement cognitive stimulation through reorienting communication, explaining location and roles. 3

Hydration and Nutrition

• Ensure adequate hydration by encouraging oral intake or consider subcutaneous/intravenous fluids if necessary. 3
• Assess for and treat constipation as a complication of dehydration. 3

Pain Management

• Assess and optimize pain control as undertreated pain is independently associated with delirium, but preferentially use non-opioid analgesics (acetaminophen) to minimize opioid-related delirium risk. 3

Pharmacological Management of Agitation

When to Use Antipsychotics

• Reserve pharmacological interventions for patients with severe agitation posing safety risks, distressing perceptual disturbances, or when preventing essential medical care. 3
• Do NOT use haloperidol or risperidone for mild-to-moderate delirium as they have no demonstrable benefit and may worsen symptoms. 3

Appropriate Antipsychotic Use

• For severe hyperactive delirium with significant distress, use low-dose antipsychotics: haloperidol, olanzapine, quetiapine, or risperidone. 3
• Discontinue immediately once distressful symptoms resolve. 3

Critical Pitfalls to Avoid

• Do not overlook co-ingestions—gabapentin overuse with opioids quadruples odds of all-cause hospitalization, drug-related hospitalization, and altered mental status compared to gabapentin alone. 8
• Do not use physical restraints as first-line management, as they worsen agitation and confusion; consider physical presence of family member or sitter instead. 3
• Do not administer sedatives without addressing underlying causes of the delirium. 3
• Do not defer imaging indefinitely in intoxicated patients without establishing a clear timeline for clinical improvement. 5
• Do not attribute acute symptoms to pre-existing dementia without investigating for acute reversible causes, as delirium commonly occurs superimposed on dementia. 4
• Do not fail to recognize hypoactive delirium, which is frequently mistaken for depression or fatigue and is the most common missed diagnosis. 4
• Do not treat asymptomatic bacteriuria in delirious patients without fever or systemic signs of infection, as this provides no benefit and increases harm from antibiotics. 3

Disposition and Follow-Up

• Implement fall and safety precautions to prevent self-harm during confused states. 3
• Continue multicomponent delirium prevention strategies including reorientation, mobilization when appropriate, and addressing all modifiable risk factors. 3
• Recognize that delirium is associated with persistent post-discharge cognitive impairment lasting months to years, requiring cognitive follow-up planning. 4