Health

Pain remover remains problem solvent

Lilah Lohr September 29 1980
Health

Pain remover remains problem solvent

Lilah Lohr September 29 1980

Pain remover remains problem solvent

Health

Lilah Lohr

As an industrial solvent, DMSO (dimethyl sulfoxide) is powerful enough to dissolve pesticides and dyes, but to many sufferers of arthritis and other painful skin and muscle ailments its strength is even more dramatic: they look to the chemical to dissolve their pain. Available both as a commercial solvent and a purer, medically prescribed chemical, DMSO has yet to have the full medical potential of its soothing qualities examined. Many of those afflicted with arthritis are touting DMSO as an unjustly suppressed wonder drug, while medical authorities are worried that harmful long-term effects may outweigh any immediate therapeutic value. “I wish I had a dime for every call we’ve had about DMSO,” says John Travis, director of development of The Arthritis Society in Toronto. “People are looking for anything to relieve their pain.”

For decades, DMSO sat innocuously on the shelves of chemical stores in its impure solvent form. Although it had been used in the treatment of injured dogs and horses, it was not until 1963 that the U.S. Food and Drug Administration

(FDA) approved the study of DMSO in humans. Readily absorbed through the skin, the solvent relieved pain and seemed to reduce swelling and help injured tissue heal. It was used widely to treat sprains, bruises and minor burns and was popular among professional athletes seeking to ease their battered bodies.

The wonder drug’s day in the sun was a short one. Scientific studies in 1965 linked DMSO with eye damage in test animals, and clinical investigation of the drug was stopped. Under certain conditions, the solvent acts as a carrier for contaminants into the bloodstream, an attribute that caused DMSO’s allure to dwindle in medical circles. “We had fairly extensive experience with it in the ’60s,” recalls Dr. Hugh Smythe, head of the rheumatic disease unit at Toronto’s Wellesley Hospital. “It relieved pain by acting as a liniment, but no more than a commercial liniment such as Heet or Absorbine Jr. One enormous disadvantage it has is that it goes right through the skin and penetrates the first layer of blood vessels. At this point, it’s absorbed through the circulation and you can detect a garlic-like breath within seconds.”

Yet, undeterred, people continued to buy and use DMSO in its various degrees of concentration as a solvent. Faced with uncontrolled consumption of the drug, the FDA quietly relaxed its restriction and permitted further cautious trials of the drug while monitoring test subjects for nearsightedness and glaucoma-like symptoms. The drug is now approved for use in the U.S. and Canada to treat interstitial cystitis, a painful bladder condition, although reliable test data is still scarce. As well, Canadian physicians are allowed to prescribe the drug for scleroderma, a condition in which skin becomes so thickened and tight that victims cannot open their mouths or move their fingers. “Scleroderma is such a terrible disease,” says Wallace Rice, chief of the miscellaneous drug division of the federal health protection branch, “that we consider there’s a high benefit-to-risk ratio. It’s the only thing that seems to work.”

But there is little to prevent physicians from applying DMSO for other than approved purposes. “DMSO is not hard to get,” says Smythe. “It’s present

in large amounts in many hospitals. You can sneak down to the lab, bring it back and paint it on anyone if you want to play with it.” And while it is not distributed for retail sale in Canada, industrial-strength DMSO can be ordered through hobby shops or other intermediaries. Still, the drug is much more regulated in Canada than in the U.S., where states such as Oregon and Florida have seen a mushrooming of clinics offering treatments using high-grade DMSO (the FDA does not have the power to regulate in-state distillation).

Arthritis victims are among the best customers of these clinics, much to the chagrin of those who are working to find a cure for the disease. “Proponents of DMSO are claiming all kinds of wondrous things,” says Peter Mathon, a spokesman for the U.S. Arthritis Foundation. “To say DMSO is a pain reliever is one thing; the foundation tends to support its use for that purpose if it is proven to be safe. But to call DMSO a cure for arthritis is a whole new ball game and it raises all kinds of false hopes.”

Legislative wheels are slowly turning in the U.S. to allocate funds for DMSO research. But one of the biggest problems facing researchers may not be money as much as methodology. The “garlic-breath” symptom caused by the drug makes it difficult to use in a double-blind study, since researchers and subjects could simply whiff to determine who was using DMSO and who was using a placebo.

Canadian pharmaceutical researchers seem complacent enough to sit back and wait for the Americans to dispel the shadows enshrouding DMSO. “We’ve been trying to encourage the companies to submit applications for clinical trials,” explains Rice. “So far, nothing concrete has resulted.” Frank W. Horner Inc., the Canadian distributor of the legal 70-per-cent DMSO solution that is prescribed for scleroderma, has no plans for further study. “We’re a relatively small company and we can’t follow every prospective use for DMSO,” says Dr. Leonard Mitchell, a vice-president at Horner. “There’s a lot of work being done in the U.S. and it’s a little confusing to see which uses will be worthwhile.”

The confusion is little solace to the one in seven people in Canada who suffer from arthritis. The crippling effects of the disease are so severe that the hopes of sufferers do not dissolve easily. But doctors do not want popular expectations of a magic balm to obscure hard research. “DMSO has been disappointing in its therapeutic value,” says Dr. Jack Stein, a medical adviser to The Arthritis Society, “and I predict that it will go the way of many of these so-called cures.”