D M Simpson

Dr D M Simpson, Mount Sinai Medical Center, New York, NY, USA; david.simpson@mssm.edu

STUDY DESIGN

Design:

randomised controlled trial.

Allocation:

unclear concealment.*

Blinding:

blinded {patients and investigators}†.*

STUDY QUESTION

Setting:

30 centres in the USA.

Patients:

307 patients (mean age 48 y, 93% men) who had ⩾2 months of moderate to severe neuropathic pain in both feet (mean Numeric Pain Rating Scale [NPRS] screening score of 3–9) secondary to HIV-associated distal sensory polyneuropathy or neurotoxic antiretroviral treatment. Treatment dose had to be stable for ⩾8 weeks for current antiretroviral drugs and ⩾21 days for other pain medications. Exclusion criteria included use of topical analgesics; pain other than HIV-associated neuropathy; cardiac, renal, hepatic, or pulmonary function abnormalities; hypersensitivity to capsaicin or opioids; and use of ⩾60 mg morphine-equivalent. …