Clinical Pharmacology & Dosing

Placebo

TRPlasebo
Also known as:Dummy treatment

A pharmacologically inert substance or sham procedure made indistinguishable from an active treatment, used mainly as a control in clinical trials.

In depth

The placebo effect is the improvement attributable to the treatment context itself, including expectation, conditioning and the patient–clinician relationship, and it involves measurable neurobiological changes such as endogenous opioid release in placebo analgesia. The response observed in a placebo arm is larger than the true placebo effect because it also includes natural history and regression to the mean.

Placebo-controlled, double-blind trials isolate the specific effect of a drug. Under the Declaration of Helsinki, a placebo control is acceptable when no proven intervention exists, or when compelling methodological reasons apply and patients are not exposed to serious or irreversible harm; otherwise a new treatment should be compared with the best proven intervention.

Clinical pearl

Improvement in a placebo arm is not purely psychological, because natural course and regression to the mean contribute; a drug's effect is judged by the difference between arms.

TRIn Turkish

Plasebo

Etkin tedaviden ayırt edilemeyecek biçimde hazırlanmış, farmakolojik olarak inert bir madde veya sahte (sham) işlemdir; başlıca klinik araştırmalarda kontrol olarak kullanılır.

Plasebo etkisi; beklenti, koşullanma ve hasta–hekim ilişkisi dahil tedavi bağlamının kendisine bağlanabilen iyileşmedir ve plasebo analjezisinde endojen opioid salınımı gibi ölçülebilir nörobiyolojik değişiklikler içerir. Plasebo kolunda gözlenen yanıt gerçek plasebo etkisinden daha büyüktür, çünkü hastalığın doğal seyrini ve ortalamaya gerilemeyi de içerir.

Plasebo kontrollü, çift kör araştırmalar bir ilacın özgül etkisini ayırt etmeyi sağlar. Helsinki Bildirgesi'ne göre plasebo kontrolü, kanıtlanmış bir girişim bulunmadığında ya da zorlayıcı metodolojik gerekçeler varsa ve hastalar ciddi veya geri dönüşümsüz zarar riskine maruz kalmıyorsa kabul edilebilir; aksi hâlde yeni tedavi kanıtlanmış en iyi girişimle karşılaştırılmalıdır.

Plasebo kolundaki iyileşme yalnızca psikolojik değildir, çünkü hastalığın doğal seyri ve ortalamaya gerileme de katkıda bulunur; bir ilacın etkisi kollar arasındaki farka göre değerlendirilir.

Diğer adları:Yalancı ilaç
Updated 24.09.2026 1 views Educational reference — verify against current sources before clinical use.

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Nocebo EffectNosebo Etkisi

The occurrence or worsening of symptoms, including adverse effects, that results from negative expectations about a treatment rather than from its pharmacological action.

 Double-Blind StudyÇift Kör Çalışma

A study design in which neither the participants nor the investigators treating or assessing them know which treatment each participant receives, to minimize performance and assessment bias.

 Randomized Controlled TrialRandomize Kontrollü Çalışma

A prospective experimental study in which participants are allocated by chance to an intervention or a control (placebo, usual care or an active comparator) and followed up to compare outcomes.

 Informed ConsentBilgilendirilmiş Onam

A person's voluntary agreement to take part in research or to undergo treatment, given after receiving and understanding adequate information about its purpose, procedures, risks, benefits and alternatives.

 Non-Inferiority TrialAşağı Olmama (Non-İnferiorite) Çalışması

A trial designed to show that a new treatment is not unacceptably worse than an active comparator, i.e., that any loss of efficacy does not exceed a prespecified non-inferiority margin (Δ).

 Naranjo AlgorithmNaranjo Algoritması

A 10-item questionnaire that estimates the probability that an adverse event was caused by a drug, classifying the relationship as definite, probable, possible or doubtful.