|October 1998||Bruce H. Woolley, Pharm.D., Editor||Vol. 5, No.10|
|Ken Hunt, Assistant Editor|
FOODS AND DRUGS CAN INTENSIFY SUNBURN
Almost everyone who enjoys the outdoors has experienced a bad sunburn, but did you know that certain foods and drugs can allow a short stint in the sun to give you a blistering sunburn? Exposing the skin to certain oils in foods, or simply taking certain drugs can set you up for a strong reaction to sunlight. Even those who do not usually burn can develop a photosensitivity due to foods or drugs.
There are two types of photosensitivity reactions. Phototoxic reactions are usually irritating chemicals from food that make their way onto the skin , become activated by the sun=s ultraviolet light, and cause an uncomfortable redness which can lead to a rash, blisters and swelling. Phototoxic reactions may also be exacerbated through ingested drugs. Photoallergic reactions, which only occur with drugs, allow the sun=s energy to trigger an immune response to the medication resulting in a redness and ultimate rash. Though the symptoms of the two are similar, photoallergic reactions are usually apparent on all parts of the body exposed to the sun, while the effects of phototoxic reactions are usually localized to the point of contact with the food chemical.
Some common foods which contain phototoxic oils are celery, fennel, figs and parsnip. Certain herbs, including rue and angelica, may also cause photosensitivity reactions. The most common occurrences, however, are in patients taking prescription medications (see table). The reactions are not usually severe and do not occur in everybody, though some people can remain sensitive for weeks after discontinuing a prescription medication. Treatment of a photosensitive reaction is similar to any sunburn: use a cool cloth or soothing lotion. Have your patients consult the clinician about the suspected photosensitive agent if the burn persists or recurs.
Adapted from: When Food and Sun Don=t Mix. Tufts University Newsletter; July 1998, vol 16
MAGNESIUM MAY HELP FIGHT OSTEOPOROSIS BATTLE
Osteoporosis is a common and potentially crippling disease for post-menopausal women. It is well established that both men and women reach a peak bone mass in their early thirties. Calcium supplementation is commonly recommended to ensure a high peak in bone mineral content (BMC) as well as a lower rate of bone loss. Magnesium, however, has also recently entered the spotlight for bone preservation.
Over half of the body=s magnesium is stored in the bone. As the body has a rapid rate of bone turnover, magnesium can easily get lost in the shuffle, especially in the elderly when less bone mineral is restored after bone breakdown. According to a May 1990 report in the Journal of Reproductive Medicine, magnesium supplements may be more important in decreasing bone loss than is calcium (1). Indeed, the authors state that late onset osteoporosis may be a manifestation of chronic magnesium deficiency.
Though not investigated nearly as often or deeply as calcium, magnesium does have some recent data. A study conducted by K.H. William Lau, et al was published in August, illustrating that Magnesium supplementation suppresses bone turnover, and therefore mineral loss, in young adults(2). The slowed turnover rate might allow bone to continue to build density at the very time when it should be maximized. The authors of the study call for more studies to illustrate that magnesium supplementation does in fact increase bone mineral in young adults.
Such a study is currently underway at Brigham Young University. The blinded study will measure increases in BMC in women, aging between 18 and 24, and how they improve with mineral supplementation. The subjects are divided into four groups: one will supplement with calcium, one with magnesium, one with both, and one group will take a placebo. The groups will supplement for approximately one year, and their bone densities will be measured every three months.
If the current research is able to show a positive correlation between magnesium and improved BMC, perhaps magnesium will be as touted as calcium in combating osteoporosis. For those affected by the disease and those who anticipate it, a possible solution is more than welcome.
1) J Repro Med, May 1990
2) K.H. Lau, et al. Daily oral magnesium supplementation suppresses bone turnover in young adult males. J Clin Endocrin and Metab. August 1998: 2742-8.
HERBAL MEDICINE B THE RISKS OF UNREGULATED REMEDIES
Alternative medicine has undergone a burst in popularity over the past decade. Exemplified by the rapidly growing herbal industry, which currently enjoys a larger market than the pharmaceutical industry, alternative approaches have become the medicine of choice for much of the country. The problem with alternative approaches, herbs in particular, is often a lack of scientific background and testing on widely used products. Furthermore, advocates of alternative medicines often deny the need for such testing. The apparently significant problem of lack of testing and quality control were recently reported in the The New England Journal of Medicine through case studies, clinical papers and by an editorial written by the editors of the journal.
Many of today=s popular herbal remedies are based on folk traditions or anecdotal reports. They are largely untested and are regulated somewhat loosely. Fortunately, most untested herbal remedies are probably harmless and are used by people who are otherwise healthy and would seek out conventional doctors if they had indication of a serious disease. On the down side, some people embrace alternative medicine exclusively, avoiding doctors and putting themselves in great danger(1).
Regulation of herbs on the governmental level came in the form of the Dietary Supplement Health and Education Act of 1994 (DSHEA), which, among other provisions, defined dietary supplements, eliminated the FDA oversite and evaluation of herbal products as foods, and declared null and void any pending FDA regulations. Subsequently, herbal products are not evaluated for safety and purity, bioavailability, nor are they examined for whether or not they support the promoter=s claims. A product can contain none of the advertised components and labels rarely include information about risks, side effects or harmful interactions. Many of these products may be somewhat effective, but the accompanying benefits and costs have rarely been scientifically established.
In the New England Journal of Medicine Editorial, the authors state: A...What most sets alternative medicine apart, in our view, is that it has not been scientifically tested and its advocates largely deny the need for such testing...[It] also distinguishes itself by an ideology that largely ignores biologic mechanisms, often disparages modern science, and relies on what are purported to be ancient practices and natural remedies (which are seen as somehow being simultaneously more potent and less toxic than conventional medicine). Accordingly, herbs or mixtures of herbs are considered superior to the active compounds isolated in the laboratory.@(2) Recently most medical schools have begun to teach alternative medicine, hospitals and health maintenance organizations offer it, and the laws in some states require health plans to cover it. Many of our currently approved remedies originated in folk traditions and have come to use after extensive testing: digitalis, chloroquine, and aspirin are examples. Physicians should help their patients understand the need for a scientific approach to herbal remedies and alternative practices.
As the Baptist minister Carlyle Marney wisely noted, AA window stuck open is as useless as a window stuck closed; In either case, you=ve lost the use of the window.@ Clinicinans should continue to insist on the accumulation of evidence for each medical breakthrough before making it available to the consumer(3). Medications and herbal medicines often have similar actions and often similar side effects. The New England Journal editorial concluded: AIt is time for the scientific community to stop giving alternative medicine a free ride. There cannot be two kinds of medicine -- conventional and alternative. There is only medicine that has been adequately tested and medicine that has not, medicine that works and medicine that may or may not work... Alternative treatments should be subjected to scientific testing no less rigorous than that required for conventional treatments.@
(1) Coppes MJ, Anderson RA, Egeler RM, Wolff JEA. Alternative therapies for the treatment of childhood cancer. N Engl J Med 1998;339:846-7.
(2) Editorial, Alternative Medicine--The Risks of Untested and Unregulated Remedies. N Engl J Med 1998 Sept 17; 339:839-41.
(3) Humber JM, Almeder, RF. Alternative Medicine and Ethics (Biomedical Ethics Reviews.), Humana Press, 1998, Totowa, N.J.
IS H. PYLORI ASSOCIATED WITH ISCHEMIC HEART DISEASE?
A recent study of eighty-eight patients with various forms of ischemic heart disease matched with eighty-eight controls sought to determine the incidence of H. pylori infection bearing the virulent cytotoxin-associated gene-A (CagA) strain. Results of the study showed that patients with ischemic heart disease had a significantly higher incidence of H. pylori infection (62%) compared with the controls (40%). In addition, patients with ischemic heart disease had a significantly higher incidence of CagA-positive infection (43%) compared with the controls (17%). The authors stated that the study demonstrates a significant relationship between CagA-positive strains of H. pylori and ischemic heart disease. Even though the mechanism for this association is unknown, there may be a link between a chronic inflammatory response and ischemic heart disease.(1)
(1) Ridker PM. Inflammation, infection and cardiovascular risk. How good is the clinical evidence ? Circulation 1998; 97:1671-74
GINKGO BILOBA AND SUBARACHNOID HEMORRHAGE
A popular herb, Ginkgo biloba, is known to be an inhibitor of platelet-activating factor and has been associated with reports of increased bleeding time, spontaneous hemorrhage, and subdural hematomas. Recently, it has been receiving attention for its purported use in improving cognition in Alzheimer=s disease patients. However a published report of a 61-year old man indicates that it may possess additional potentially severe adverse effects. The patient presented with a five-day history of headache, back pain, nausea, and sleepiness. An extensive physical and neurological examination revealed no abnormalities except an elevated blood pressure (135/85 mmHg) and an increased bleeding time (6 minutes). The only medication being taken was Ginkgo biloba (40mg 3 to 4 times/day). A lumbar puncture yielded a slightly xanthochromic fluid without blood on macroscopic examination. A subarachnoid hemorrhage was diagnosed. The ginkgo biloba was immediately discontinued. At the four month followup the patient was asymptomatic, and the bleeding times were within normal range (3 min.). The authors stated that the use of this preparation in patients with known risk factors for intracranial hemorrhage is not recommended.(1)
(1) Vale S. Subarachnoid haemorrhage associated with ginkgo biloba. Lancet 1998 Jul 4; 352:36.
RALOXIFENE REDUCES SPINAL/VERTEBRAL FRACTURES
A two year study of 7705 osteoporotic women reported at the recent European Congress on Osteoporosis showed a reduced vertebral fracture rate in women with previous spinal fractures by 38% and a 52% reduction for women with no previous spinal fractures. The authors stated: AThese data are the first to show that a [SERM] can significantly reduce the risk of spinal fracture.@ The study also found a decrease in serum and urine levels of markers of bone turnover and increased hip and spine bone density by 2% to 2.5%.
The information and opinions expressed in the Therapeutics Letter do not necessarily reflect the official policy of the sponsoring organizations.