WSJ Promotes Pamlab Product (More or Less)

For some completely unknown reason, today's WSJ gives free publicity to Pamlab, LLC, a Louisiana company that sells an oral, "high-dose" vitamin B supplement for peripheral neuropathy. 

Treatment of neuropathy with various forms of vitamin B has been around for at least decades, and the promotion of B supplementation rears up periodically in the lay press (as in the case of today's WSJ) and mostly bottom-feeding medical journals. The popularity of vitamin B6 (pyridoxine), specifically, as a neuropathy treatment probably has its genesis in the use of the vitamin to reduce the risk of isoniazid-induced neuropathy when treating tuberculosis. We're talking Eisenhower era.

The problem is that clinicians forget (or never knew) that high-dose B6, itself, can cause a toxic sensory neuropathy, which was documented in 1983 in the NEJM. Reversible B6 neuropathies were also described in 172 women in 1987 who used lower vitamin dosages (mean, 117 mg/d ± 92). These clinical neuropathies were more likely to occur with longer durations of treatment.

Pamlab's supplement contains 25 mg of the active form of pyridoxine, with a recommended dosage of 1-2 tablets per day. This dosage is within the standard deviation of the B6 range reported in the 1987 case series. Pamlab says that its supplement (which is only available by prescription and costs a stunningly high $40-$70 per month) has been shown in unpublished clinical trials to improve foot sensation and pain, writes the WSJ. (The supplement also contains 2.8 mg of L-methylfolate [the active form of folate, or B9] and 2 mg of methylcobalamin [a form of B12].)

The WSJ also cites a Cochrane review from July, which concluded that there is currently insufficient evidence to use vitamin B supplementation for neuropathy. The Cochrane authors found only 13 randomized or "quasi"-randomized studies (N = 741) from the mid-1960s to 2005, which compared vitamin B supplementation with placebo in general peripheral neuropathy. A considerably fewer number of trials compared vitamin B complex with an active control. Placebo-controlled trials provided mixed efficacy results, and active-comparator trials suggested that vitamin B supplementation is less efficacious in the short term than other agents. (Specific forms of vitamin B, with the exception of thiamine, are not highlighted in the Cochrane abstract.)

Pamlab informed the WSJ of an unblinded study of its vitamin B supplement, which was presented last month by a podiatrist at an unidentified scientific conference. The NIH Clinical Trials database includes a randomized, double-blind, placebo-controlled phase 4 study of the proprietary product in patients with type 2 diabetic neuropathy. The study is currently recruiting patients at selected US locations.

Why the WSJ chose to showcase Pamlab's vitamin B product, without 1) having more definitive scientific information to support its use in neuropathy and 2) citing the risk of neuropathy with B6 supplementation, is a minor mystery.