Is Eperisone (Eperisone) 50mg twice daily (BID) for 3 days and Pregabalin (Pregabalin) 75mg once daily (OD) a safe regimen for a patient with Chronic Kidney Disease (CKD) experiencing neck pain?

Safety Assessment of Eperisone 50mg BID and Pregabalin 75mg OD in CKD with Neck Pain

This regimen requires immediate dose adjustment for pregabalin based on the patient's creatinine clearance, as pregabalin is primarily renally eliminated and the current dose of 75mg daily may be inappropriate without knowing renal function. 1

Critical Renal Function Assessment Required

Before proceeding with this regimen, you must calculate creatinine clearance using the Cockcroft-Gault equation, as this is the FDA-recommended method for pregabalin dose adjustment in renal impairment 1. The KDIGO 2024 guidelines emphasize that GFR must be considered when dosing all renally cleared medications, and pregabalin specifically requires dose adjustment based on creatinine clearance 2, 3.

Pregabalin Dosing Algorithm by Renal Function

The FDA label provides specific dose adjustments based on creatinine clearance 1:

• CLcr ≥60 mL/min: Standard dosing applies (75mg daily is acceptable as starting dose)
• CLcr 30-60 mL/min: Reduce total daily dose by 50% (37.5mg daily would be appropriate)
• CLcr 15-30 mL/min: Reduce total daily dose by 75% (approximately 18.75-25mg daily)
• CLcr <15 mL/min: Further dose reduction required (as low as 25mg every other day)
• Hemodialysis patients: Require supplemental doses after each 4-hour dialysis session 1

The proposed 75mg once daily dose is only safe if the patient has CLcr ≥60 mL/min 1. Without knowing the patient's renal function, this dose carries significant risk of drug accumulation and neurotoxicity 4.

Specific Safety Concerns in CKD

Pregabalin-Related Risks

Pregabalin accumulation in CKD can cause myoclonic encephalopathy, altered consciousness, and seizures, even when plasma levels appear within therapeutic range 4. A case report documented myoclonic encephalopathy in a patient with acute renal failure (creatinine 451.3 μmol/L) despite pregabalin levels of only 3.42 μg/mL 4.

Abrupt discontinuation of pregabalin in CKD patients can precipitate seizures, as demonstrated in a case where stopping 150mg/day in a patient with eGFR 10 mL/min led to tonic-clonic seizure 4 days later 5. Therefore, if dose adjustment is needed, taper gradually over minimum 1 week 1.

Monitoring Requirements

The KDIGO 2024 guidelines mandate monitoring of eGFR, electrolytes, and therapeutic medication levels for drugs with potential adverse effects or nephrotoxicity 2. For pregabalin in CKD:

• Check renal function before initiating therapy 2, 3
• Reassess renal function within 2-4 weeks after starting or dose changes 2
• Monitor for neurological symptoms: confusion, myoclonus, altered consciousness 4
• Assess for signs of drug accumulation: excessive sedation, dizziness, ataxia 1

Eperisone Considerations

There is insufficient evidence in the provided guidelines regarding eperisone dose adjustment in CKD. However, the KDIGO 2024 guidelines recommend reviewing all medications for potential nephrotoxicity and limiting over-the-counter medicines that may be harmful 2. Given the lack of specific guidance, standard dosing of 50mg BID for 3 days appears reasonable for short-term use, but renal function should still be assessed.

Alternative Pain Management Strategies

For neck pain in CKD patients, the KDIGO 2015 guidelines recommend a stepwise approach 2:

First-line (non-pharmacological): Exercise, local heat application, massage, acupuncture, cognitive behavioral therapy 2, 6

Second-line (pharmacological): If non-pharmacological approaches fail, use an adapted WHO analgesic ladder that accounts for pharmacokinetic changes in CKD 2. For neuropathic pain specifically, gabapentin and pregabalin are recommended, but must be renally dosed 6.

Critical Action Steps

1. Calculate creatinine clearance using Cockcroft-Gault equation immediately 1
2. Adjust pregabalin dose according to FDA table based on CLcr 1
3. If CLcr <60 mL/min, reduce pregabalin to 37.5mg daily or less 1
4. Monitor neurological status closely for first 2-4 weeks 4
5. Reassess renal function within 2-4 weeks 2
6. Consider non-pharmacological interventions as first-line therapy 2

Common Prescribing Pitfalls to Avoid

Do not use serum creatinine alone to assess renal function - you must calculate creatinine clearance using the Cockcroft-Gault formula, as this is what FDA dosing tables are based on 1.

Do not abruptly discontinue pregabalin if dose adjustment is needed - taper over minimum 1 week to prevent withdrawal seizures 1, 5.

Do not assume standard dosing is safe without knowing renal function - pregabalin clearance is directly proportional to creatinine clearance (56% correlation), making dose adjustment essential 7.