HERB-DRUG INTERACTIONS CAN BE DANGEROUS
Ginseng can diminish effectiveness of warfarin.
Ginseng is a popular herbal supplement, believed by many to improve physical energy level and the functioning of the immune system. At least 16% of people who take prescription drugs also take such herbal products, and 15 million Americans therefore may experience interactions between the two. Moreover, many people do not inform their health care providers that they are using complementary, alternative health products.
Most drug-herb interactions are as yet unknown, but any substances that are metabolized by the hepatic cytochrome P-450 (CYP) enzyme system are prime candidates for them. For example, warfarin, which interferes with blood clotting by suppressing the production of vitamin K-dependent coagulation factors, is one medication metabolized and eliminated via the hepatic CYP enzyme system. In surgical patients, rats, and human platelets in vitro, ginseng also has been shown to prolong clotting time, and it contains components, namely ginsenosides, that may induce the action of certain liver enzymes. In one case report, ginseng seemed to counteract rather than augment the ability of warfarin to prolong clotting time, possibly reducing the drug's effectiveness, when taken concurrently.
To test the hypothesis, 20 young, healthy volunteers participated in a double-blind, placebo-controlled trial of concurrent ginseng and warfarin use over four weeks. Instructions to maintain usual dietary habits were given to keep the level of vitamin K relatively constant. When ginseng was consumed for two to three weeks, plasma warfarin levels were decreased and the drug's ability to prolong clotting time was therefore reduced, as indicated by a lower international normalized ratio. The authors suggest that some studies that failed to find an interaction between ginseng and warfarin were too short-it may take a week or longer for substances to induce or inhibit CYP enzyme activity.
Although the study does not reveal whether elderly, ill people, for whom warfarin is usually prescribed, are affected by ginseng in the same way that young, healthy volunteers are, both clinicians and patients should be aware of the potential of the herb to interfere with the drug's therapeutic action. -FM
Yuan CS, et al. Ann Intern Med 2004;141(1):23-7.
PAIN LEVELS OF NURSING HOME RESIDENTS
Timing of communication varies.
The frequency of pain assessment and the timing of the communication about it among nursing home residents and clinicians vary greatly by institution, according to a recent study.
The directors of nursing at 63 nursing homes in New Haven County, Connecticut, were asked by telephone the following questions concerning communication pertaining to pain management: "How often is pain assessed (by nursing staff) in residents who do not complain of pain?"; "How often is pain assessed (by nursing staff) in residents who do complain of pain?"; "When are clinicians notified of pain assessments?"; "How often is pain assessed by clinicians?"; "When is pain reassessed (by nursing staff) after a clinician's intervention?" Pain management processes were evaluated by taking the most common response to each question as representative of the standard procedure in nursing homes and comparing all other responses to it.
Each question had as many as 39 responses. The most common answers directors of nursing gave were as follows: the nursing staff assesses pain quarterly in residents who don't complain of it (29%) and at every shift in residents who do (19%); clinicians are notified of the status of a resident's pain when treatment of it is ineffective (11%) and upon changes in pain intensity (11%); in general, the presence of pain is assessed by a clinician at least every 30 to 60 days (22%); and pain is reassessed by the nursing staff one hour after an intervention (65%). Using the highest percentage per response as the standard pertaining to each question, pain was assessed at least quarterly in residents without known pain in 76% of all the nursing homes and at least every shift in residents with known pain in 46% of them; and in 42%, clinicians were informed of pain assessments when treatment was ineffective.
The researchers recommend further study of the use of chart reviews to determine actual practice because in this study directors of nursing rather than nursing staff and other clinicians were interviewed. However, the results suggest that providers at nursing homes should work to improve the process of communication. -JC
Jenq GY, et al. Arch Intern Med 2004;164(14):1508-12.
PAIN AMONG DAY SURGERY PATIENTS
Telephone follow-up can help to correct misconceptions.
A qualitative study has revealed that patients who undergo day surgery often have misconceptions about postoperative pain and its management.
Two hundred thirty-eight patients who had undergone one of four types of surgery (anal, hernia repair, arthroscopy, or breast reduction or augmentation) were randomly assigned to either an intervention group or a control group. Although patients in both groups were provided pain diaries to be completed and returned, as well as postoperative education in pain management and surgical care, the intervention group also received preoperative education in the management of postoperative pain. To provide instruction in pain management, a nurse researcher telephoned patients in the intervention group on the first three postoperative days, while those in the control group were telephoned at home only on the fifth postoperative day (intervention-group patients also were telephoned on that day).
The results showed that at the time of the first postoperative telephone call, patients couldn't remember the hospital discharge instructions that they had received; on the second postoperative day they couldn't remember the nurse researcher's instructions given on the previous day. On the third day, in anticipation of the nurse researcher's call, patients were prepared with questions. Patients had several misconceptions about pain and its management. For example, they believed that they could base their activity levels on the degree of pain that they felt, which often led to significant pain if they overextended themselves because they had no initial pain. Some patients restricted their activities, not eating or moving about, for example, in order to avoid pain, while others believed that pain was to be endured, and were reluctant to take analgesia. Other misconceptions concerned adverse effects-some patients were afraid to take the medications for fear of constipation, for example. Others reported that they had decreased the dosage to test the medication's effectiveness.
Not only does it appear that it takes more time than expected for patients to absorb all the information they receive, the nurse researcher found that patients ask more questions than can be addressed during follow-up calls. The study also reveals the importance of documenting patient education; many patients neither remember instructions given orally nor read the written ones. -JC
Dewar A, et al. J PeriAnesth Nurs 2004;19(4):234-41.
TRAUMA AND DEPRESSION
Do they make women ill?
Studies have documented the association between depression and poor physical health, but the relationship between posttraumatic stress disorder (PTSD), and physical health has not been examined as carefully. A large, cross-sectional survey of female military veterans was analyzed to learn more about the relationships among PTSD, depression, and physical health.
In a sample of more than 30,000 female veterans, among the 14% who had been diagnosed with PTSD by a physician, 89% were diagnosed also with depression. Twenty-five percent of the women reported a diagnosis of depression without PTSD, and 61% reported neither diagnosis.
Although the mean age of the women who had PTSD was only 45 years, 90% of them reported at least one serious medical condition. Arthritis, chronic low-back pain, chronic lung disease, hypertension, and obesity were common, and 10% had coronary artery disease or cancer, the two principal causes of death among women in the United States. Women with depression did not have as large a burden of illness as did those with PTSD, but they had significantly greater physical health problems than did women who had neither depression nor PTSD. PTSD is severely disabling---self-reported physical functioning scores of women with PTSD were lower than those of women with arthritis, chronic lung disease, or congestive heart failure. This is clinically significant because poor health status is an independent risk factor in a heightened risk of dying.
These strong associations between physical and mental illness call for treating depression and PTSD concurrently with the medical disorders they so often accompany.-FM
Frayne SM, et al. Arch Intern Med 2004;164:1306-12.