Is pregabalin (Pregabalin) 75mg once daily (OD) and eperisone (Eperisone) safe for a patient with cervical radiculopathy and chronic kidney disease (CKD)?

Pregabalin and Eperisone Safety in CKD Patients with Cervical Radiculopathy

Pregabalin 75mg once daily requires dose adjustment in CKD patients and should be administered in divided doses (not once daily), while eperisone safety data in CKD is insufficient to recommend its use.

Pregabalin Dosing in CKD

Critical Dosing Error in Your Question

• The FDA label explicitly states pregabalin must be administered in two or three divided doses, not once daily, regardless of renal function 1
• For cervical radiculopathy, the recommended starting dose is 75mg twice daily (150mg total daily dose), not 75mg once daily 1

Renal Dose Adjustment Requirements

• Pregabalin clearance is 56-58% proportional to creatinine clearance, making dose adjustment mandatory in CKD 2
• The FDA recommends calculating creatinine clearance using the Cockcroft-Gault equation before initiating therapy 1
• For CrCl 30-60 mL/min: Reduce total daily dose by 50% compared to normal renal function 1, 2
• For CrCl 15-30 mL/min: Further reduce by an additional 50% 1, 2
• For CrCl <15 mL/min or hemodialysis: Pregabalin is highly cleared by dialysis and requires supplemental dosing after each 4-hour treatment 1, 2

Specific Dosing Algorithm for CKD

• If CrCl ≥60 mL/min: Start 75mg twice daily (150mg/day total), may increase to 150mg twice daily based on response 1
• If CrCl 30-60 mL/min: Start 25-50mg twice daily (50-100mg/day total) 1, 2
• If CrCl 15-30 mL/min: Start 25mg once or twice daily (25-50mg/day total) 1, 2
• If CrCl <15 mL/min: Consider alternative therapy or use 25mg once daily with extreme caution 1, 2

Monitoring Requirements in CKD

• KDIGO 2024 guidelines emphasize that CKD patients are more susceptible to medication adverse effects and require monitoring of eGFR, electrolytes, and therapeutic levels for drugs with narrow therapeutic windows 3
• Pregabalin's half-life and AUC increase proportionally as renal function declines, increasing risk of accumulation and adverse effects 2

Efficacy Evidence for Cervical Radiculopathy

Clinical Trial Data

• Pregabalin 75mg twice daily demonstrated significant pain reduction in cervical radiculopathy patients, with VAS scores improving significantly at 4 weeks (P=0.001) and 8 weeks (P<0.0005) 4
• In a multiracial Asian population study, 54% of patients remained on 75mg twice daily dosing with good efficacy, though 44% discontinued due to somnolence 4
• Pregabalin monotherapy or add-on therapy showed substantial pain alleviation in cervical radiculopathy over 12 weeks in primary care settings 5

Important Caveat About Asian Populations

• Somnolence occurred early even at the lowest dose (75mg twice daily) in Asian patients, with 44% dropout rate, suggesting potential need for even lower starting doses in this population 4

Eperisone Considerations in CKD

Lack of Safety Data

• No guideline or FDA labeling information exists regarding eperisone dose adjustment in CKD
• The KDIGO 2024 guidelines recommend considering GFR when dosing medications cleared by the kidneys and reviewing medications that may be harmful 3
• Without established safety data in renal impairment, eperisone use in CKD patients carries unknown risk

Alternative Muscle Relaxant Considerations

• Given the lack of CKD-specific data for eperisone, consider alternatives with established renal dosing guidelines if muscle relaxation is needed
• The KDIGO guidelines emphasize reviewing and limiting medications without established safety profiles in CKD 3

Common Prescribing Pitfalls to Avoid

Critical Errors

• Never prescribe pregabalin once daily - this violates FDA labeling and risks subtherapeutic dosing 1
• Never use serum creatinine alone - always calculate CrCl using Cockcroft-Gault equation before prescribing 1, 2
• Never assume 75mg total daily dose is adequate - the therapeutic starting dose for radiculopathy is 150mg/day divided 1, 6, 4
• Never ignore acute illness - reassess renal function during intercurrent illness as transient worsening increases drug accumulation risk 3

Monitoring Strategy

• Establish baseline CrCl before initiating therapy 1, 2
• Monitor for somnolence, dizziness, and peripheral edema - the most common dose-dependent adverse effects 1, 4
• Reassess renal function at least annually, more frequently if CrCl <60 mL/min 3
• Review all over-the-counter medications and herbal remedies that may interact or cause nephrotoxicity 3

Recommended Approach

For a CKD patient with cervical radiculopathy:

1. Calculate CrCl using Cockcroft-Gault equation 1, 2
2. Start pregabalin at renally-adjusted dose in divided doses (twice or three times daily) 1
3. Avoid eperisone unless compelling indication exists and benefits clearly outweigh unknown renal risks 3
4. Monitor renal function, electrolytes, and adverse effects closely 3
5. Consider dose escalation only after assessing tolerability and ensuring stable renal function 1, 4