Can an adult patient with chronic full‑body muscle hypertonicity (jaw/TMJ, neck, shoulders, upper back) persisting during sleep, anxiety, racing thoughts, fragmented PAP‑treated obstructive sleep apnea, and seizure disorder controlled with lamotrigine benefit from gabapentin or pregabalin (Lyrica)?

Gabapentin and Pregabalin for Chronic Muscle Hypertonicity with Anxiety and Sleep Fragmentation

Pregabalin (Lyrica) is the preferred choice over gabapentin for this patient, as it directly addresses multiple core symptoms—anxiety, racing thoughts, and sleep fragmentation—with robust evidence, while gabapentin lacks adequate data for this specific presentation. 1, 2, 3

Rationale for Pregabalin

Direct Anxiolytic Effects

• Pregabalin is FDA-approved in the EU for generalized anxiety disorder and is considered a first-line agent by the World Federation of Societies of Biological Psychiatry, with rapid onset of effect (typically ≤1 week) and broad-spectrum activity against both psychic and somatic symptoms of anxiety. 3
• The mechanism involves binding to the α2δ subunit of voltage-dependent calcium channels, inhibiting excitatory neurotransmitter release in overexcited CNS neurons—directly relevant to this patient's "fight or flight" state. 1, 3
• Pregabalin specifically improves racing thoughts and anxiety symptoms that are driving the muscle hypertonicity, with 53% of its effect on sleep being direct and 47% mediated through anxiety reduction. 2

Sleep Architecture Improvement

• Pregabalin has a direct effect on sleep maintenance that is distinct from its anxiolytic properties, improving all forms of insomnia and reducing sleep fragmentation. 2, 4
• Polysomnographic studies demonstrate that pregabalin primarily affects sleep maintenance, which directly addresses this patient's frequent awakenings despite PAP therapy. 4
• Improvement in sleep correlates with reduction in functional impairment and quality of life measures, and is associated with reduced daytime sleepiness despite initial sedation risk. 2

Dosing Strategy

• Start at 75 mg twice daily (150 mg/day total) to minimize initial sedation, which occurs in 10-30% of patients depending on titration speed. 2, 5
• Titrate gradually over 1-2 weeks to 150 mg twice daily (300 mg/day), then to 200-300 mg twice daily (400-600 mg/day) as needed for anxiety and sleep symptoms. 1, 2
• The therapeutic range for anxiety and sleep is 200-600 mg/day divided into 2-3 doses, with most patients responding at 300-450 mg/day. 1, 2, 3

Why Not Gabapentin

Insufficient Evidence Base

• Gabapentin has not been well studied for central pain or muscle hypertonicity syndromes, though it has shown efficacy in other forms of neuropathic pain. 6
• Guidelines classify gabapentin as a second-line treatment only for central poststroke pain (a different condition), with weaker evidence than pregabalin. 6
• No robust data exist for gabapentin's effects on anxiety-driven muscle tension or sleep fragmentation in the context described. 6

Critical Considerations with Lamotrigine

Seizure Control Priority

• This patient is already on lamotrigine for seizure control with no recent episodes—do not discontinue or reduce lamotrigine. 5
• Pregabalin has inferior efficacy to lamotrigine for seizure control in newly diagnosed partial seizures (52% vs 68% seizure-free for 6+ months), so it should be used as an adjunct, not a replacement. 5
• Lamotrigine itself can reduce central pain and cold-induced pain, but only 44% of patients have a good clinical response, and it does not specifically address anxiety or sleep maintenance. 6

Monitoring and Pitfalls

Common Adverse Effects

• Dizziness (17%), somnolence (9%), and weight gain (6%) are the most common side effects with pregabalin, typically occurring in the first 2 weeks of treatment. 5
• Initial sedation usually resolves after 2 weeks, and improvement in sleep quality is associated with reduced daytime sleepiness despite this early effect. 2
• Gradual discontinuation over 1 week minimizes withdrawal risk, which is generally low. 3

Drug Interactions

• Pregabalin has minimal drug interactions and does not interfere with lamotrigine metabolism or efficacy. 1, 5
• The patient's naltrexone, topical lidocaine/ketamine, and Botox injections do not interact with pregabalin. 1

OSA and PAP Therapy

• Pregabalin does not worsen obstructive sleep apnea and may improve PAP adherence by reducing anxiety-related sleep fragmentation. 2, 4
• Continue nightly PAP therapy as the standard of care for OSA, with pregabalin addressing the residual sleep fragmentation and anxiety that PAP alone does not resolve. 6, 7

Alternative if Pregabalin Fails

Clonidine for Sympathetic Overactivity

• If pregabalin is ineffective or poorly tolerated after 4-6 weeks at adequate doses, consider adding clonidine patch (0.1-0.3 mg weekly) to suppress sympathetic nervous system outflow and reduce the "fight or flight" state. 8
• Monitor blood pressure closely, as clonidine can cause hypotension and bradycardia. 8

Avoid Sedating Agents

• Do not use benzodiazepines, sedating antidepressants (trazodone, mirtazapine), or antipsychotics (quetiapine, olanzapine) in this patient, as they cause significant sedation and worsen OSA. 8, 9