An active placebo is a
placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures.
In general, placebos can af ...
that produces noticeable side effects that may convince the person being treated that they are receiving a legitimate treatment, rather than an ineffective placebo.
Nomenclature
According to a 1965 paper, the term "concealed placebo" (German: Kaschiertes Placebo) was suggested in a 1959 paper published in German.
Example
An example of an active placebo is the 1964 work of Shader and colleagues who used a combination of low-dose phenobarbital plus atropine to mimic the sedation and dry mouth produced by phenothiazines.
Morphine
Morphine is a strong opiate that is found naturally in opium, a dark brown resin in poppies (''Papaver somniferum''). It is mainly used as a pain medication, and is also commonly used recreationally, or to make other illicit opioids. T ...
and
gabapentin
Gabapentin, sold under the brand name Neurontin among others, is an anticonvulsant medication primarily used to treat partial seizures and neuropathic pain. It is a first-line medication for the treatment of neuropathic pain caused by diabeti ...
are painkillers with the common side effects of sleepiness and dizziness. In a 2005 study assessing the effects of these painkillers on
neuropathic pain
Neuropathic pain is pain caused by damage or disease affecting the somatosensory system. Neuropathic pain may be associated with abnormal sensations called dysesthesia or pain from normally non-painful stimuli (allodynia). It may have continuous ...
,
lorazepam
Lorazepam, sold under the brand name Ativan among others, is a benzodiazepine medication. It is used to treat anxiety disorders, trouble sleeping, severe agitation, active seizures including status epilepticus, alcohol withdrawal, and c ...
was chosen as an active placebo because it is not a painkiller but it does cause sleepiness and can cause dizziness.
Testing from the late 1950s onwards on narcotic analgesics like morphine also has used
dicyclomine
Dicycloverine, also known as dicyclomine, sold under the brand name Bentyl in the US, is a medication that is used to treat spasms of the intestines such as occur in irritable bowel syndrome. It is taken by mouth or by injection into a muscl ...
as an active placebo, and on some occasions it was reported to cause the Straub mouse tail reaction, as do most narcotics.
Clonidine is now finding more use as an active placebo for narcotics.
References
*{{cite journal, title=Phenobarbital and atropine in combination, an active control substance for phenothiazine research, url=https://dx.doi.org/10.1016%2F0022-3956%2864%2990018-4, last1=Shader, first1=R. I., last2=Cohler, first2=J., last3=Elashoff, first3=R., last4=Grinspoon, first4=L., journal=
Journal of Psychiatric Research
The ''Journal of Psychiatric Research'' is a monthly peer-reviewed medical journal covering research in four major areas of psychiatry: clinical studies on normal and pathological human behavior; basic studies in psychiatry and related fields; cl ...
, volume=2, issue=3, date=October 1964, pages=169–183, author-link4=Lester Grinspoon, access-date=7 September 2020, doi=10.1016/0022-3956(64)90018-4, pmid=14242375
Medical terminology
Clinical research