Drug Topics - January 28, 2008 - (Page 21) 21 ed that a continued release of cytokines caused by stress or infection could potentially lead to a diagnosis of CFS. Cytokines are primarily made up of proteins and glycoproteins and are part of the signaling in an immune response. They are released when the immune system is fighting pathogens. Cytokines also can signal the production of more cytokines. Some researchers found that when patients are administered cytokines, they have caused fatigue, while other researchers have found that administering cytokines to CFS patients resulted in some clinical improvement. It is also important to point out that several studies have shown that CFS patients are more likely to have allergies, either as part of their medical history or may be suffering more from allergic symptoms as part of their CFS. This is another reason why researchers have investigated cytokines as part of a pathogenesis leading to CFS; however, conclusive evidence has not been demonstrated through studies at this time. Some studies were also conducted to determine whether problems with blood pressure and pulse regulation were a problem in CFS patients. This was studied as some investigators also noted that a subset of CFS patients also had neurally mediated hypotension. Neurally mediated hypotension (NMH) occurs when there is an abnormal reflex reaction between the brain and the heart. A test conducted to diagnose patients suspected of having NMH is the tilt-table test. This test involves placing the patient on a flat table. The table is then tilted to a 70 degree angle for 45 minutes. Vitals are monitored during the test. An NMH diagnosis is assigned when the patient develops a lower blood pressure under these conditions in conjunction with experiencing symptoms such as being slow to respond to verbal stimuli, a feeling of lightheadness and dizziness, and visual dimming. A common symptom of CFS patients includes a feeling of lightheadness or worsened fatigue when they stand for prolonged periods of time. CFS patients report that these symptoms worsen if the area is warmer than the patient is normally accustomed to experiencing. These experiences are similar to those of patients who have NMH. In one study in which CFS patients were also subject to this same test, 96% of the individuals also experienced these same symptoms. Only 29% of the control subjects who did not have a CFS or NMH diagnosis experienced these symptoms. Not all patients diagnosed with CFS experience symptoms similar to NMH; therefore, blood pressure and pulse regulation abnormalities have not been determined to be a cause of CFS. Other studies included hormonal causes of CFS since many patients frequently report experiencing physical or emotional stress prior to CFS. When people experience physical or emotional stress, it typically activates the hypothalamic pituitary adrenal axis, or HPA axis. This leads to an increased release of cortisol and other hormones. Cortisol and corticotrophin-releasing hormone (CRH) influence the immune system and may affect some aspects of behavior. Cortisol suppresses inflammation and cellular immune activation. Lower levels than normal may decrease immune cell activation. Some CFS patients’ cortisol levels have been lower than healthy patients; however, the levels obtained were still within the normal limits for this hormone; therefore, cortisol levels cannot help to diagnose patients with CFS. Currently, no scientific evidence supports CFS as being caused by a nutritional deficiency, although various studies have looked at nutritional markers as a cause of CFS. CFS duration Currently, the duration of CFS and the number of people who recover from this condition are not fully known. Studies conducted demonstrated varied improvement rates. These rates ranged from 8% to 63%, with a median of approximately 40% of patients improving during follow-up. Full recovery from CFS appears to be rare at this time, with an average of only 5% to 10% of patients reporting a total remission. CFS case examples What follows are some case studies of CFS patients. Take a look and see how you would evaluate them. First case example Jane Patient presents to your pharmacy seeking OTC products to help make her “feel better.” She complains of feeling like she never recovered from the “bad cold” she had approximately two months ago. She constantly feels tired and complains of headaches and periodic joint pain. She further explains to you that she went to her physician last week and “he didn't find anything.” She tells you that her “lab work was normal,” but she isn't sure which tests were completed. She does not take any medications and indicates that she is normally quite healthy. She has no medical problems. She did some of her own searching on the Internet and wonders if she might have CFS. What information should be provided to this patient? Table 2 General guidelines for pharmacotherapy in CFS patients Limit polypharmacy if possible. CFS patients report being more sensitive to medications. This can be accomplished through the use of medications with more than one indication such as depression and pain. Start low, go slow with dosing. This is another method to limit the medication sensitivities experienced by CFS patients. One-half of the recommended dosing is a good starting point. Utilize a systematic approach to medication therapy. CFS patients will often require trials of multiple different medications. Counsel CFS patients on potential side effects as these patients frequently report experiencing side effects. Source: Adapted from www.cdc.gov/cfs/cfstreatmentHCP .htm http://www.cdc.gov/cfs/cfstreatmentHCP.htm
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