Evidencia Médica e Investigación en Salud

Contenido por año, Vol. y Num.

Índice de este artículo

Información General

Instrucciones para Autores

Mensajes al Editor


>Revistas >Evidencia Médica e Investigación en Salud >Año 2011, No. 1

Velásquez-Paz A, Téllez-Zenteno JF
El efecto placebo
Evid Med Invest Salud 2011; 4 (1)

Idioma: Español
Referencias bibliográficas: 65
Paginas: 21-35
Archivo PDF: 264.44 Kb.

[Texto completo - PDF]


El efecto placebo es un fenómeno generalizado y universal que ha acompañado a la práctica de la medicina desde sus inicios. Durante muchos años el placebo ha sido considerado una sustancia inerte, sin embargo, en medicina existe confusión al identificar el vocablo placebo como un objeto y no como un efecto. Las recientes investigaciones han demostrado que éste es un genuino evento psicobiológico atribuible a todo el contexto terapéutico.
En este artículo analizamos el concepto “efecto placebo”, sus mecanismos e implicaciones en la clínica, algunos aspectos metodológicos de los estudios con placebos, la definición de los estudios de equivalencia, sus aspectos metodológicos y análisis propios de este tipo de estudios.

Palabras clave: placebo, efecto placebo, estudios de equivalencia, ensayos clínicos.


  1. Kleijnen J, M de Craen A, Everdingen JV, Krot L. Placebo effects in double-bind clinical; a review of interactions with medications. Lancet 1994; 344:1347-49.

  2. Aronson J. When I use a Word… Please, please me. BMJ 1999; 318:716.

  3. Kaptchuk TJ, Kerr CE, Zanger A. Placebo controls, exorcism, and the devil. Lancet 2009; 374: 134-35.

  4. Viniegra L. El efecto placebo. Ciencia 1987; 38: 131-46.

  5. De Craen AJM, Kaptchuk TJ, Tijssen JGP, Kleijnen J. Placebos and placebo effects in medicine: historical overview. J R Soc Med 1999; 92: 511-515.

  6. Hornung J. Was ist ein Placebo? Die Bedeutung einer Korrekten Definition für die klinische Forschung. Forsch Komplementärdmed 1994; 1: 160-5.

  7. Beecher HK. The powerful of placebo. J Am Med Assoc 1995; 159: 1602-6.

  8. Benedetti F. Placebo effects: understanding the mechanisms in health and disease. New York: Oxford University Press, 2009.

  9. Benedetti F. Mechanisms of placebo and placebo-related effects across diseases and treatments. Annu Rev Pharmacol Toxicol 2008; 48: 33–60.

  10. Kirsch I. Response expectancy as a determinant of experience and behavior. Am Psychol 1985; 40: 1189–202.

  11. Benedetti F, Arduino C, Amanzio M. Somatotopic activation of opioid systems by target-directed expectations of analgesia. J Neurosci 1999; 19: 3639–48.

  12. Price DD, Milling LS, Kirsch I, Duff A, Montgomery GH, Nicholls SS. An analysis of factors that contribute to the magnitude of placebo analgesia in an experimental paradigm. Pain 1999; 83: 147–56.

  13. Vase L, Robinson ME, Verne GN, Price DD. The contributions of suggestion, desire, and expectation to placebo effects in irritable bowel syndrome patients. An empirical investigation. Pain 2003; 105: 17–25.

  14. De la Fuente-Fernandez R, Ruth TJ, Sossi V, Schulzer M, Calne DB, Stoessl AJ. Expectation and dopamine release: mechanism of the placebo effect in Parkinson’s disease. Science 2001; 293: 1164–66.

  15. Petrovic P, Dietrich T, Fransson P, et al. Placebo in emotional processing—induced expectations of anxiety relief activate a generalized modulatory network. Neuron 2005; 46: 957–69.

  16. Volkow ND, Wang G, Ma Y, et al. Expectation enhances the regional brain metabolic and the reinforcing effects of stimulants in cocaine abusers. J Neurosci 2003; 23: 11461–68.

  17. Voudouris NJ, Peck CL, Coleman G. Conditioned response models of placebo phenomena: further support. Pain 1989; 38: 109-16.

  18. Voudouris NJ, Peck CL, Coleman G. The role of conditioning and verbal expectancy in the placebo response. Pain 1990; 43: 121–28.

  19. Siegel S. Explanatory mechanisms for placebo effects: Pavlovian conditioning. InEn: Guess HA, Kleinman A, Kusek JW, Engel LW, eds. The science of the placebo: toward an interdisciplinary research agenda. London: BMJ Books, 2002: 133–57.

  20. Stewart-Williams S, Podd J. The placebo effect: dissolving the expectancy versus conditioning debate. Psychol Bull 2004; 130: 324–40.

  21. Montgomery GH, Kirsch I. Classical conditioning and the placebo effect. Pain 1997; 72: 107–13.

  22. Amanzio M, Benedetti F. Neuropharmacological dissection of placebo analgesia: expectation-activated opioid systems versus conditioning-activated specific subsystems. J Neurosci 1999; 19: 484–94.

  23. Finniss DG, Benedetti F. Mechanisms of the placebo response and their impact on clinical trials and clinical practice. Pain 2005; 114: 3–6.

  24. Colloca L, Benedetti F. Placebos and paink illers: is mind as real as matter? Nat Rev Neurosci 2005; 6: 545–52.

  25. Grevert P, Albert LH, Goldstein A. Partial antagonism of placebo analgesia by naloxone. Pain 1983; 16:129–43.

  26. Levine JD, Gordon NC. Influence of the method of drug administration on analgesic response. Nature 1984; 312: 755–56.

  27. Fields HL, Levine JD. Placebo analgesia a role for endorphins. Trends Neurosci 1984; 7: 271–73.

  28. Benedetti F, Amanzio M, Maggi G. Potentiation of placebo analgesia by proglumide. Lancet 1995; 346: 1231.

  29. Benedetti F, Amanzio M. The neurobiology of placebo analgesia: from endogenous opioids to cholecystokinin. Prog Neurobiol 1997; 52: 109–25.

  30. Wager TD, Scott DJ, Zubieta JK, Wager TD, Scott DJ, Zubieta J-K. Placebo effects on human mu-opioid activity during pain. Proc Natl Acad Sci USA 2007; 104: 11056–61.

  31. Kong J, Gollub RL, Rosman IS, et al. Brain activity associated with expectancy-enhanced placebo analgesia as measured by functional magnetic resonance imaging. J Neurosci 2006; 26: 381–88.

  32. Benedetti F, Colloca L, Torre E, et al. Placebo-responsive Parkinson patients show decreased activity in single neurons of subthalamic nucleus. Nat Neurosci 2004; 7: 587–88.

  33. Benedetti F, Lanotte M, Colloca L, Ducati A, Zibetti M, Lopiano L. Electrophysiological properties of thalamic, subthalamic and nigral neurons during the anti-parkinsonian placebo response. J Physiol 2009; 587: 3869–83.

  34. Mayberg HS, Silva JA, Brannan SK, et al. The functional neuroanatomy of the placebo effect. Am J Psychiatry 2002; 159: 728–37.

  35. Benedetti F, Amanzio M, Vighetti S, et al. The biochemical and neuroendocrine bases of the hyperalgesic nocebo effect. J Neurosci 2006; 26: 12014–22.

  36. Scott DJ, Stohler CS, Egnatuk CM, Wang H, Koeppe RA, Zubieta JK. Placebo and nocebo effects are defined by opposite opioid and dopaminergic responses. Arch Gen Psychiatry 2008; 65: 220–31.

  37. Diehl HS. Medicinal treatment of the common cold. J Am Med Assoc 1953; 101: 2042-2049.

  38. Whitner CW, Von Korff M. Regression to the mean in treated versus untreated chronic pain. Pain 1992; 50: 281-5.

  39. Leroy GV. The effectiveness of the xanthine drugs in the treatment of angina pectoris. J Am Med Assoc 1941;116 (10): 921-5

  40. McDonald C, Mazzuca S, McCabe G. How much of the placebo “effect” is really statistical regression? Stat Med 1983; 2: 417-27.

  41. Wells RE. Use of reserpine (Serpasil) in the management of chronic alcoholism. JAMA 1957; 163 (6): 426-9.

  42. Kienle G, Kiene H. The powerful Placebo Effect; Fact or fiction? J Clin Epidemiol 1997; 50: 1311-1318.

  43. Greigner Th, Gold H, Cattell M, Travell J. A method for the evaluation of the effect of drugs on cardiac pain in patients with angina of effort. A study of Hhellin (Vissamin). Am J med 1950; 9: 143-155.

  44. Blonberg LH. Treatment of disseminated sclerosis with active and inactive drugs. Lancet 1957; 1: 431-2.

  45. Keats AS, Beecher HK. Pain relief with hypnotic doses of barbiturates and a hypothesis. J Pharmacol Exp Ther 1950; 100: 1-13.

  46. Ader R. Conditioned Inmunopharmacological Effects in animals; Implications for a Conditioning Model of Pharmacotherapy. In; White L, Tursky B, Schartz GE, Eds. Placebo-Theory, Research, and Mechanism. New York; Guilford Press; 1985.

  47. Peck C, Coleman G. Implications of placebo theory for clinical research and practice in pain management. Theor Med 1991; 12: 247-270.

  48. Voudouris NJ, Peck CL. Coleman G. The role of conditioning and verbal expectancy in the placebo response. Pain 1990; 43: 121-8.

  49. Lasagna L, Mosteller F, Felsinger JM, Beecher HK. A study of the placebo response. Am J Med 1954; 155: 339-41.

  50. Gravenstein JS, Devloo RA, Beecher HK. Effect of antitussive agents on experimental and pathological cough in man. J Appl Physiol 1954; 7: 119-39.

  51. Green DM. Preexisting conditions, placebo reactions and “side effects”. Ann Intern Med 1964; 60 (2): 255-265.

  52. Reidenberg MM, Lowenthal DT. Adverse nondrug reaction. N Eng J Med 1968; 279 (13): 678-679.

  53. Wolf S, Pinsky RH. Effects of placebo adm inistration and the concurrence of toxic reactions. J Am Med Assoc 1954; 155: 339-41.

  54. Lasagna L, Laties VG, Dohan JL. Further studies on the Pharmacology of the placebo administration. J Clin Invest 1958; 37: 533-7.

  55. Abbot FK, Mack M, Wolf S. The action of Banthine on the stomach and duodenum of man with observations on the effects of placebo. Gastroenterology 1952; 20: 249-61.

  56. Weiner M, Weiner G. The kinetics and dynamics of responses to placebo. Clin Pharmacol Ther 1996; 60: 247-254.

  57. Rabkin JG, McGrath PJ, Quitkin FM, Tricamo E, Stewart JW, Klein DF. Effects of pill-giving on maintenance of placebo response in patients with chronic mild depression. A J Pshychiatry 1990; 147: 1622-6.

  58. Schteingart DE, Weiner M, Marlin R. Pseudoephedrine enhances weight loss in people with modest obesity. Satellite symposium, Sixth International Congress on Obesity, Tokio 1990.

  59. Makuch R, Johnson M. Issues in planning and interpreting active control equivalence studies. J Clin Epidemiol 1989; 42: 503-11.

  60. World Medical Association Declaration of Helsinki. Recomm endations guiding physicians in biomedical research involving biomedical research involving human subjects. JAMA 1997; 277: 925-6.

  61. Temple R, Ellemberg S. Placebo-Controlled Trials and Active-Control Trials in the Evaluation of New treatments. Ann Intern Med 2000; 133; 455-63.

  62. Sachar DB. Placebo controlled clinical trials in gastroenterology. A position paper of the American College of gastroenterology. Am J Gastroenterology 1984; 79: 913-7.

  63. Tramer MR, Reynolds DJ, Moore RA, McQuay HJ. When placebo controlled trials are essential and equivalence trial are inadequate. BMJ 1998; 317: 875-90.

  64. Leber P. Hazards of inference: the active control investigation. Epilepsia 1989; 30: S57-63.

  65. Jones B, Jarvis P, Lewis JA, Ebburt AF. Trials to assess equivalence; the importance of rigorous methods. 1996; 313: 36-9.

>Revistas >Evidencia Médica e Investigación en Salud >Año2011, No. 1

· Indice de Publicaciones 
· ligas de Interes 
Derechos Resevados 2007