Selecting a Treatment Regimen
ÎBefore deciding on a pharmacotherapeutic agent, see product Prescribing Information for:
> Drug interactions > Adverse events > Side effects
ÎNo good evidence exists for efficacy of complementary/ alternative therapies in DPNP
ÎFor first-tier agents:
> Titrate to maximum tolerated dose > Reduction in pain of at least 50% from baseline should be expected if agent is effective > Some improvement in pain reduction should be expected within 3 weeks of initiation of therapy
> Consider modification of therapy if no improvement seen
ÎModification of therapy, if inadequate response to treatment or intolerance of adverse events:
> Change to another first-tier agent, using mechanism of action as a guide OR > Change to a second-tier agent, using mechanism of action as a guide OR > Add a different first- or second-tier agent, using principles of rational polypharmacy:
■ Complementary mechanisms of action ■ Decrease toxicity ■ No additive adverse events or side effects ■ Possible synergies
Table 2A. Medications Specifically Approved for DPNP by FDA Drug
Dosage Form Recommended Dosage
First Tier Serotonin-norepinephrine reuptake inhibitors (SNRIs)
Duloxetine Cymbalta®
20, 30, 60 mg capsules
60 mg/d (if renal impairment, lower starting dose and gradually increase); to blunt potential nausea, initiate therapy at 30 mg/d taken with food for first week
> Contraindicated if concomitant MAOIs, uncontrolled narrow- angle glaucoma
Comments
> Not recommended if end-stage renal disease, severe renal impairment (CrCl < 30 mL/min), hepatic insufficiency, active alcoholism
> Avoid other SNRIs, TCAs, tramadol
Alpha-2-delta calcium channel modulators/anticonvulsants (α2
Pregabalin Lyrica®
25, 50, 75, 100, 150, 200, 225, 300 mg capsules
Start with 50 mg bid-tid if CrCl ≥ 60 mL/min (if lower CrCl, adjust starting dose downward); titrate in increments based on effectiveness/tolerability up to max 300 mg/d
δ CCMs)
> Schedule V controlled substance
> Avoid other α2
> If therapy ended, withdraw gradually over min 1 wk
δ CCMs CrCl, creatinine clearance; MAOIs, monoamine oxidase inhibitors; TCAs, tricyclic antidepressants.
