Re:Re:Vitamin B12 as a Treatment for Pain - 2019년 review논문

[문형철]

beyond reason

고농도 비타민 B12는 급만성 통증에 효과적임....

https://www.painphysicianjournal.com/current/pdf?article=NjAxNQ%3D%3D&journal=116

Background: 

First isolated as cyanocobalamin in 1948, vitamin B12 has been explored for pain treatment almost since its discovery. With the advent of the opioid epidemic, safer treatments for pain are needed.

Objectives: 

Our objective was to compile the latest information on potential mechanisms from animal studies and clinical trial data on vitamin B12 for the treatment of pain conditions.

Study Design: 

We conducted a narrative review.

Methods: 

PubMed was searched using the terms “methylcobalamin pain”, “hydroxycobalamin pain”, “cyanocobalamin pain”, and “vitamin B12 pain.” Animal studies that identified mechanisms of action for the effects of pain were collected. Clinical trials utilizing larger, pharmaceutical doses of vitamin B12 (> 100 μg/dose) in pain treatment were identified and reviewed.

Results: 

Animal studies support multiple beneficial effects of vitamin B12 including the regeneration of nerves and the inhibition of cyclooxygenase enzymes and other pain-signaling pathways. In addition, animal studies have demonstrated synergistic benefits of vitamin B12 combined with other pain medications, including nonsteroidal anti-inflammatory drugs and opiates. Clinical trials provide evidence for the effectiveness of vitamin B12 for the treatment of low back pain and neuralgia, although data is still fairly limited and optimal treatment regimens have not been identified.

Limitations: 

More large, double-blind placebo-controlled trials are needed to fully establish efficacy and best dosing parameters.

Conclusion: 

Vitamin B12 may prove to be an adjunctive or integrative treatment for pain conditions. While more research is needed, considering the low incidence of side effects and overall safety, B12 may be an additional tool to consider for pain treatment.

Safety

While vitamin B12 orally or by injection is typically well-tolerated with a low incidence of adverse events (50), there are rare case reports of allergic reactions, anaphylaxis, and other side effects. In most reports of anaphylactic reactions to injected B12, high-dose oral supplementation is still tolerated. 

However, there are exceptions noted in the literature (51). Although, de- sensitization protocols for reversing IgE-mediated allergy to B12 have also shown success (52). Other rare, but potential side effects include a small but significant drop of potassium in patients with macrocytic anemia and low serum potassium, which in extreme cases could be fatal. In patients with severe macrocytic anemia with hematocrit under 25%, vitamin B12 injections were shown to drop potassium levels initially by an average of 0.4 mEq/L since potassium is utilized in the produc- tion of red blood cells (53). Potassium should be moni- tored in this subset of patients. There are case reports of acne-like, voluminous folliculitis after intramuscular B12 that clears readily upon discontinuation (54). Dry mouth, nausea, and blurred vision have also been re- ported with B12 (55). An additional study using vitamin B6, B12, and folic acid in diabetic nephropathy showed decreased kidney function and increased cardiovascu- lar events with the vitamins, although the study only included 118 patients for the primary outcome at 36 months (56). A separate study of 2056 patients with ne- phropathy followed for over 3 years, including a subset with diabetic nephropathy, showed no significant im- pact of these same vitamins on mortality, cardiovascu- lar, or other secondary outcomes (57). Drug references list congestive heart failure and pulmonary edema as serious adverse events, yet a review of the literature did not turn up any case reports.