Painful diabetic neuropathy

Painful diabetic neuropathy is neuropathic pain. Start an SNRI, gabapentinoid, TCA or sodium-channel blocker, switch class if one fails, avoid opioids, and consider 10-kHz spinal cord stimulation for refractory pain.

1. It is neuropathic pain, so neuropathic rules apply. Burning, stabbing pain with numbness in a stocking distribution reflects a disease of the somatosensory nerves. Neuropathic pain guidelines therefore apply, and simple analgesics or anti-inflammatories are not the core treatment ¹.
2. First-line drugs come from four classes. The 2022 AAN guideline recommends offering a TCA, SNRI, gabapentinoid or sodium-channel blocker, with roughly comparable effect sizes ². The 2025 NeuPSIG update gives strong recommendations and first-line status to SNRIs, pregabalin, gabapentin and TCAs ¹.
3. If one class fails, switch class. When a patient lacks meaningful improvement or has significant adverse effects, AAN advises offering a trial from a different effective class rather than adding an opioid. AAN also advises screening patients with this pain for concurrent mood and sleep disorders (Level B) ².
4. Topicals and second-line agents. NeuPSIG 2025 rates capsaicin 8% patches, capsaicin cream and lidocaine 5% plasters as weak second-line options; tramadol is no longer listed second line; opioids are weak third-line ¹. Capsaicin 8% stays on the feet for 30 minutes, repeated no more often than every 3 months ³.
5. Opioids are not recommended. AAN recommends against opioids for painful diabetic neuropathy, even though tapentadol extended release carries an FDA indication for severe diabetic neuropathic pain requiring an opioid ²⁴.
6. Refractory pain: 10-kHz spinal cord stimulation. In SENZA-PDN, 79% of stimulated patients versus 5% of controls had at least 50% relief at 3 months ⁵.

Check renal function before dosing: avoid duloxetine when GFR is below 30 mL/min, and reduce gabapentinoid doses in renal impairment ⁶⁷.

• AAN 2022 effective classes: TCAs, SNRIs, gabapentinoids and sodium-channel blockers; opioids are recommended against ².
• NeuPSIG 2025 first-line: SNRIs, pregabalin, gabapentin and TCAs, all with strong recommendations ¹.
• Capsaicin 8% patch: NNT 13.2 with very few adverse-event withdrawals; a weak, second-line recommendation ¹.
• Capsaicin 8% application: up to four systems, 30 minutes on the feet; do not apply to broken skin ³.
• Gabapentin absorption is saturable, so bioavailability falls from about 60% to 34% as the daily dose rises ⁷.
• SENZA-PDN enrolled patients refractory to gabapentinoids and at least one other class, HbA1c ≤10% and BMI ≤45 ⁵.
• Enriched-enrollment withdrawal trials show benefit only in patients who already tolerated and responded to the drug ⁸.

• Adding an opioid after a gabapentinoid fails instead of switching to another effective class ².
• Reading an enriched-enrollment withdrawal result as the benefit every new patient will get ⁸.
• Doubling gabapentin and expecting double the exposure; saturable absorption blunts the rise ⁷.
• Treating tapentadol's FDA indication as a guideline endorsement; AAN still recommends against opioids ²⁴.