Placebo: Difference between revisions
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==Clinical use== | ==Clinical use== | ||
Placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition. They have been used as a means of suggestion to individual patients. A [[randomized controlled trial]] found that placebo medications that the patient perceives as more expensive will have more placebo effect than placebos that are | Placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition. They have been used as a means of suggestion to individual patients. A [[randomized controlled trial]] found that placebo medications that the patient perceives as more expensive will have more placebo effect than placebos that are perceived as less expensive.<ref name="pmid18319411">{{cite journal |author=Waber RL, Shiv B, Carmon Z, Ariely D |title=Commercial features of placebo and therapeutic efficacy |journal=JAMA : the journal of the American Medical Association |volume=299 |issue=9 |pages=1016–7 |year=2008 |month=March |pmid=18319411 |doi=10.1001/jama.299.9.1016 |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=18319411 |issn=}}</ref> | ||
Many doctors report prescribing medications in part for the placebo effect.<ref>{{Cite journal | Many doctors report prescribing medications in part for the placebo effect.<ref>{{Cite journal |
Revision as of 20:27, 10 February 2010
A placebo is any medication or treatment expected to have no physiological effect; the generally synonymous term sham treatment is sometimes used to describe a surgical or other procedure, more visible than a pill. According to the United States National Library of Medicine, a placebo is defined as a "dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol."[1]
The use of placebos has many ethical issues, and they are different in the research and general clinical contexts.
Placebo versus placebo effect
Placebo is different from a placebo effect, which is defined as an "effect usually, but not necessarily, beneficial that is attributable to an expectation that the regimen will have an effect, i.e., the effect is due to the power of suggestion"[2] Thus the placebo effect can be a component of the effect of a treatment that has a true physiologic role; whereas a placebo has no intention of physiologic benefit.
The placebo effect is very common. In a randomized controlled trial of pregabalin for fibromyalgia the following occurred:[3]
study group | Patients reporting at least "much" improvement in their pain |
---|---|
pregabalin | 43% |
placebo | 35% |
Among the patients who received pregabalin, most of the benefit was due to placebo effect. The benefit due to the drug was 43% minus 35% or 8%. Thus if 100 patients receive pregabalin:
- 35 will improve due to placebo effect
- 8 will improve due to pregabalin (number needed to treat is 100/8 or 13)
- 57 will not improve
Clinical use
Placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition. They have been used as a means of suggestion to individual patients. A randomized controlled trial found that placebo medications that the patient perceives as more expensive will have more placebo effect than placebos that are perceived as less expensive.[4]
Many doctors report prescribing medications in part for the placebo effect.[5]
While some clinicians and ethicists argue that it is unethical to deceive patients by giving them a placebo, others, within constraints, suggest:[6]
- placebo can be an effective treatment.
- Its use does not always entail deception.
- In select cases, use of the placebo may even be morally imperative
In one case study, a patient complained of pain even after receiving an apparently appropriate opioid analgesic. The attending clinicians then, in addition, administered an injected saline placebo, suggesting it could help relieve his pain, and it did. The suggestion was not untrue. Had it not relieved the patient's pain, than additional interventions would have been appropriate, or, at the least, a careful risk-benefit analysis of these additional therapies. Most pain medicine specialists agree that with proper precautions, there is no upper limit to the opioid dosage that may be necessary to relieve pain.
Had the patient asked for specific identity of the drug, the treating personnel would be ethically required to tell the truth. The patient would be free to refuse it, but, if the responsible physician believed that the injection might indeed help the patient psychologically, using the placebo would be ethical.
An ethically acceptable way to offer a placebo, according to Lichtenberg and colleagues, could be:
I would like to offer you a pill which I believe can help lessen your suffering. I do not know exactly how it works. I have other pills to offer whose mechanism is clearer, but I am not sure that they will work better for you, and they may also entail more serious side effects.[6]
Some would argue this is deceptive, but others make the counterargument that placebo effects are real. They contend that the argument that this is unethical assumes "only through pharmacology or similarly respectable and rational procedures can the doctor aid the patient. This has never been true, and even in an age of evidence based medicine remains untrue." [6]
Another case where placebo use might be justified would be where a patient demands a specific pharmacologic treatment that the clinician believes is inappropriate, in the presence of a self-limiting condition. In such a case, the physician might administer a placebo, reassuring the patient that he will recover, but that the treatment given is more appropriate.
In yet another case, the clinician prescribes an appropriate dose of a drug, such as a tricyclic antidepressant, the pharmacological effect of which is known to start only after several weeks of taking the medication. If the patient reported immediate relief, it can reasonably be assumed that the relief is due to the placebo effect. This does become an ethical challenge if the patient is relieved, but the drug, even at a low starting dosage, is not without risk.
Ethical considerations for guidelines that result from this work might include:
- The first intent of prescribing the placebo must be the well-being of the patient. The decision must not be made because the treatment economically benefits the prescriber.
- When a placebo is offered, it must be in the sincere intent of relieving suffering. It would be unethical for the physician to give it simply in the interest of suppressing demands to "do something."
- If placebo does not help, it must be immediately stopped, and alternative treatment given if one exists. Rather perversely, not to withdraw the placebo in such a situation may lead to what could be considered a reverse effect: the patient might distrust a true analgesic or sedative, and psychosomatically resist its effects. In such a case, not only would the substitute drug not help, but it would expose the patient to increased risk without benefit.
- Placebo can be used only when standard treatment is ineffective, the side effects of the usual treatment are unacceptable, or there is no accepted treatment. This can lead to the challenging question of whether a referral might be made to a CAM practitioner, of a type that the physician does not believe will have any effect on the actual disease. It is quite arguable, however, that if the physician, in this situation, believes that a CAM method may actually help, it is unethical not to refer to such a practitioner.
- The physician must answer direct questions about the identity and expected effects of the placebo.
- If the placebo helps, it must be continued in the absence of a more effective treatment. If the placebo effect is unexpected, as in the case of immediate response to the tricyclic antidepressant, it cannot simply be stopped. Should the potential dangers of such a pharmacologic intervention be significant, then the physician must consider a safer alternative, even a true placebo, rather than discontinuing all treatment.
Adverse effects
Placebos may be associated with adverse effects.[7][8][9]
Clinical choice of complementary and alternative medicine
One of the challenges in evaluating complementary and alternative medicine (CAM) is ruling out the placebo effect. If the conventional practitioner does not have a treatment to offer, and a CAM method, in the practitioner's experience, may help even if believed to be a placebo effect, it should be presented to the patient. In like manner, if the patient suggests a CAM approach that the physician believes would be ineffective or dangerous, the physician should make that opinion known, and then allow the patient to make his or her own choice.
If the patient has comorbid conditions for which conventional treatment is desired, as long as the CAM treatment will not interfere with the conventional treatment, the physician is not relieved from the duty of care for the other diseases. Should the physician be unwilling to continue to treat a patient that uses a CAM technique, that does not free the physician from the requirement to ensure continuing conventional care for other conditions. If the CAM treatment may directly interfere with other treatment, consultation with the CAM practitioner(s), bioethics resources, and possibly legal counsel becomes appropriate.
Research use
In any medical study, every patient- including those of a control group, if any- should be assured of the best proven diagnostic and therapeutic method. From The Declaration of Helsinki[10] |
The more common use of placebos is for the patients in the control group of a randomized controlled trial. The World Medical Organization's interpretation of the Declaration of Helsinki, says placebo controls are unethical if there is a standard treatment for the disease being studied.[10] When no treatment is available, placebo controls are ethical. This is by no means agreed by all medical scientists.
References
- ↑ Anonymous (2024), Placebo (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Anonymous (2024), Placebo effect (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Mease PJ, Russell IJ, Arnold LM, et al (March 2008). "A randomized, double-blind, placebo-controlled, phase III trial of pregabalin in the treatment of patients with fibromyalgia". The Journal of Rheumatology 35 (3): 502–14. PMID 18278830. [e] Trial registration number not provided by authors, but is likely to be NCT00333866
- ↑ Waber RL, Shiv B, Carmon Z, Ariely D (March 2008). "Commercial features of placebo and therapeutic efficacy". JAMA : the journal of the American Medical Association 299 (9): 1016–7. DOI:10.1001/jama.299.9.1016. PMID 18319411. Research Blogging.
- ↑ Tilburt, Jon C; Ezekiel J Emanuel, Ted J Kaptchuk, Farr A Curlin, Franklin G Miller (2008-10-23). "Prescribing "placebo treatments": results of national survey of US internists and rheumatologists". BMJ 337 (oct23_2): a1938. DOI:10.1136/bmj.a1938. Retrieved on 2008-10-24. Research Blogging.
- ↑ 6.0 6.1 6.2 Lichtenberg P, Heresco-Levy U, Nitzan U (2004 December), "The ethics of the placebo in clinical practice", J Med Ethics 30(6): 551–554., DOI:10.1136/jme.2002.002832
- ↑ (2009) Placebos Have Side Effects Too
- ↑ Rief W, Nestoriuc Y, von Lilienfeld-Toal A, Dogan I, Schreiber F, Hofmann SG et al. (2009). "Differences in adverse effect reporting in placebo groups in SSRI and tricyclic antidepressant trials: a systematic review and meta-analysis.". Drug Saf 32 (11): 1041-56. DOI:10.2165/11316580-000000000-00000. PMID 19810776. Research Blogging.
- ↑ Amanzio M, Corazzini LL, Vase L, Benedetti F (2009). "A systematic review of adverse events in placebo groups of anti-migraine clinical trials.". Pain. DOI:10.1016/j.pain.2009.07.010. PMID 19781854. Research Blogging.
- ↑ 10.0 10.1 Rickham PP (July 1964). "Human Experimentation. Code of Ethics of the World Medical Association. Declaration of Helsinki". British Medical Journal 2 (5402): 177. PMID 14150898. PMC 1816102. [e]
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