Nootropic
Nootropic ( ancient Greek νόος 'mind' , τρόπος 'phrase' , 'direction') is a vaguely defined term that is used in pharmacology as well as in other areas such as complementary medicine , wellness and anti-aging .
In the broadest sense is drugs , dietary supplements which have a beneficial effect on, or other substances central nervous system is attributed, incorrectly referred to as "brain doping agent" or "smart drugs" ( smart drugs ), respectively. In the narrower and scientific- pharmacological sense, drugs are meant that are approved or are currently being tested as antidementia drugs for the treatment of dementia . So z. B. also the antidementia drugs Huperzine A and Piracetam .
A market for nootropics is increasingly developing. Among other things, substances without temporary approval and those without a proven effect or long-term studies on side effects are in decline.
Definition
The word “nootropic” was coined in 1972 by the Romanian doctor Corneliu E. Giurgea (1923–1995). Giurgea was involved in the synthesis of the substance piracetam in 1964 , which is now one of the best-known nootropics. He chose the term in a lexical analogy to the term psychotropic .
Giurgea was Professor of Neurophysiology at the Faculty of Medicine in Bucharest and in 1963 he became head of the Department of Neuropharmacology at UCB in Belgium .
According to Giurgea, nootropics are drugs that share the essential characteristics of Piracetam, namely:
- A direct activation of the integrative activities of the brain that mediate an immediate positive effect on the mind.
- This activation should selectively affect the telencephalon and not manifest in other levels of the brain.
- So as to have a restorative effect on problems of higher brain activity.
In the following years he expanded this definition to include additional criteria. To be considered a nootropic, a substance should:
4. Improve learning and memory.
5. Increase the resilience of learned behaviors / memories to the conditions that tend to disturb them (e.g. electric shock and hypoxia ).
6. Protect the brain against various physical or chemical injuries (e.g. from barbiturates or scopolamine ).
7. Improve the effectiveness of the tonic control mechanisms of the cerebral cortex at the subcortical levels of the brain.
8. Not having the usual pharmacology of other psychoactive drugs (e.g. sedation , motor stimulation) work.
9. The drug should have very few side effects and extremely low toxicity.
Differentiation of “brain doping agents” and anti-dementia drugs
The terms “nootropic” and “cognitive enhancer”, “brain doping agent” or anti-dementia drugs are sometimes taken to be equivalent. However, a distinction should be made.
Any nootropic substance found by Giurgea's criteria can actually improve cognition. A substance with a positive cognitive effect is only a nootropic in the sense of the definition if it also has a neuroprotective effect and is free of toxicity. Brain stimulants like amphetamines are not strictly nootropics, although they can bring about cognitive enhancements as these can be accompanied by toxic effects.
Mode of action
Studies of the modes of action of nootropics have revealed various pharmacological effects; but a single predominant type of effect that shares the entire class of drugs does not prevail. All the facts influence the cholinergic function: By increasing the choline uptake, the production and turnover of acetylcholine is increased, which has an effect on muscarinic and nicotine receptors . Piracetam also increases the density of acetylcholine receptors in the frontal cortex by 30% -40%.
Energy supply in the form of adenosine triphosphate (ATP) is crucial for the survival of the brain. Brain cells have to get their own ATP from glucose and oxygen and cannot absorb ATP from other cells. Piracetam increases the activity of the adenylate kinase enzyme, which converts adenosine diphosphate (ADP) into ATP and adenosine monophosphate (AMP). This reduces the drop in the concentration of ATP in the brain when there is a lack of oxygen and accelerates the recovery from hypoxia, also due to the increase in oxidative glycolysis . Piracetam also increases cerebral blood flow, cerebral oxygen consumption, metabolic rate and cerebral glucose metabolism in chronically impaired function of the human brain.
Another mechanism of action is a reduction in platelet aggregation and an improvement in cellular membrane fluidity, presumably through the incorporation of phospholipids into the membrane.
Approved nootropics in the red list
In the Red List , the following substance groups are listed in main group 11 " Antidementia (nootropics)":
- Herbal anti-dementia drugs (nootropics)
- Ginkgo extracts
- Chemically Defined Antidementia Drugs (Nootropics)
- Calcium antagonists , cholinesterase inhibitors , dihydroergotoxin , nicergoline , piracetam , purine derivatives, pyritinol , modafinil , nicotine
effectiveness
The effectiveness of many substances known as nootropics is controversial. The best proven in larger populations, the effect of acetylcholinesterase inhibitor donepezil , rivastigmine and galantamine and the NMDA antagonist memantine . Even if this assessment has not remained uncontroversial, these drugs are currently recommended in guidelines for the treatment of most forms of dementia.
The study results on the other substances are contradicting. This is especially true for ginkgo , which is currently the most widely prescribed nootropic. Other drugs are considered ineffective in evidence-based medicine for the treatment of cognitive disorders in the context of dementia.
Individual evidence
- ↑ DAK Health Report 2009, main topic: Doping in the workplace ( Memento from June 26, 2011 in the Internet Archive )
- ↑ £ 200,000 'smart' drugs seizure prompts alarm over rising UK sales . In: The Guardian . (English, theguardian.com [accessed October 24, 2014]).
- ↑ a b c d Doru Georg Margineanu: A Weird Concept with Unusual Fate: Nootropic Drug . In: Revue des Questions Scientifiques . tape 182 , no. 1 , 2011, p. 33–52 (English, PDF ).
- ^ A b c d e R. Balaraman, J. Shingala: Molecule of the Millenium . In: Indian Journal of Pharmacology . tape 34 , 2002, p. 439-440 (English, PDF ).
- ↑ Alexander Kurz, B. Van Baelen: Ginkgo biloba compared with cholinesterase inhibitors in the treatment of dementia. A review based on meta-analyzes by the cochrane collaboration . In: Dementia and Geriatric Cognitive Disorders . tape 18 , no. 2 , 2004, ISSN 1420-8008 , p. 217-226 , PMID 15237280 (English, Epub, June 28, 2004).
