Should I add pregabalin (lyrica) to an 18-year-old female with subjective intermittent burning feet, no diabetes, and no hypothyroidism, with normal sensation to pinprick, normal temperature, normal vibration, and normal proprioception tests?

Pregabalin Is Not Recommended for an 18-Year-Old Female with Subjective Intermittent Burning Feet and Normal Neurological Examination

Pregabalin should not be added to treat this 18-year-old female with subjective intermittent burning feet given her normal neurological examination findings and lack of underlying conditions like diabetes or hypothyroidism.

Assessment of Current Clinical Picture

The patient presents with:

• 18-year-old female
• Subjective intermittent burning feet
• No diabetes
• No hypothyroidism
• Normal neurological examination:
  • Normal pinprick sensation
  • Normal temperature sensation
  • Normal vibration testing
  • Normal proprioception

Rationale Against Pregabalin Use

Lack of Diagnostic Criteria for Neuropathic Pain

• The patient has normal neurological examination findings, which does not support a diagnosis of neuropathic pain or peripheral neuropathy
• Neuropathic pain typically requires evidence of nerve damage or dysfunction, which is not present in this case 1

Age-Related Concerns

• Pregabalin carries significant risks in younger patients, including:
  • Somnolence (occurs in 15-25% of patients)
  • Dizziness (occurs in 27-46% of patients)
  • Cognitive impairment 2
  • Risk of medication discontinuation due to adverse events (18-28%) 2

Risk-Benefit Analysis

• The evidence supporting pregabalin is primarily for confirmed neuropathic pain conditions:
  • Diabetic peripheral neuropathy
  • Postherpetic neuralgia
  • Central neuropathic pain 3
• This patient has none of these conditions and lacks objective findings of neuropathy

Alternative Approach to Management

First Steps

1. Further diagnostic evaluation:

   • Consider blood tests to rule out vitamin B12 deficiency, folate deficiency
   • Consider screening for autoimmune conditions that might cause early neuropathy
   • Evaluate for possible mechanical causes of foot pain

2. Conservative management:

   • Proper footwear
   • Foot hygiene
   • Regular exercise to improve circulation
   • Topical agents for symptomatic relief if needed 1

If Symptoms Persist

• Consider topical treatments with minimal systemic effects:
  • Lidocaine patches (5%)
  • Capsaicin cream 1

Important Cautions About Pregabalin

If neuropathic pain is eventually confirmed and pregabalin is considered in the future:

• Pregabalin can cause QT prolongation when combined with other medications, as demonstrated in a case report of a 76-year-old woman who experienced ventricular fibrillation after pregabalin was added to her medication regimen 3
• Pregabalin can cause myoclonic encephalopathy, even without drug accumulation 4
• Pregabalin requires dose adjustment in renal impairment 5

Conclusion

Given the patient's young age, normal neurological examination, and lack of confirmed neuropathy, the risks of pregabalin therapy outweigh any potential benefits. A more appropriate approach would be further diagnostic evaluation to identify the underlying cause of her symptoms, followed by targeted treatment based on those findings.