Psychoactive drugs actions

Baraban JM, Worley PF, Snyder SH. Second messenger systems and psychoactive drug action focus on the phosphoinositide system and lithium. Am J Psychiatry 1989 146 1251-1260. 

The four neurotransmitters previously discussed (acetylcholine, norepinephrine, dopamine, and serotonin) have been relatively well studied and at one time w ere thought to be the main chemicals involved in neural transmission. However, the development of more sophisticated research techniques has led to the recognition that many more neurotransmitters await discovery. A thorough discussion of recent advances in neuropharmacology is beyond the scope of this text, but some developments have already had a substantial impact on our understanding of psychoactive drug actions. 

Nichols, DE. Differences between the mechanisms of action of MDMA, MBDB, and the classical hallucinogens. Identification of a new therapeutic class Entactogens. J Psychoactive Drugs 18 305-313, 1986. 

Julien, RM. (1997). A Primer of Drug Action A Concise, Nontechnical Guide to the Actions, Uses, and Side Effects of Psychoactive Drugs. New York W. H. Freeman. 

The potential of psychoactive TDM to improve therapy has been limited to date because many clinicians lack basic PK training and pharmaceutical marketing departments actively discourage TDM of their drugs. In order to correct this situation, clinicians must appreciate the basic PK principles necessary to correctly order and interpret TDM results, as well as to understand or predict drug actions in their individual patients. 

A growing number of drugs are used that affect the many neurotransmitters in the brain benzodiazepines and others act on GABAergic transmission antidepressants, such as monoamine oxidase inhibitors and tricyclic antidepressants, are thought to increase the concentration of transmitter amines in the brain and so elevate mood—these will also act at peripheral nerve terminals, so interactions with them are a combination of peripheral and central actions. Levodopa (L-dopa) increases central as well as peripheral dopamine, and the newer class of psychoactive drugs, the selective serotonin reuptake inhibitors (SSRIs) of which the ubiquitous fluoxetine (Prozac) is best known, act in a similar way on serotonergic pathways. 

EXTENSIONS AND COMMENTARY I know of no record of 2C-H ever having been tried by man. It has been assumed by everyone (and probably correctly so) that this amine, being an excellent substrate for the amino oxidase systems in man, will be completely destroyed by the body as soon as it gets into it, and thus be without action. In virtually all animal assays where it has been compared with known psychoactive drugs, it remains at the less-active end of the ranking. 

EXTENSIONS AND COMMENTARY There is a term dose-dependent in pharmacology. When there is a complex action produced by a drug, then each of the components of this mixture of effects should be expected to become more intense following a bigger dose of the drug. This is certainly true with most of the actions of psychoactive drugs. 

In cases of depression and low self-esteem, the action of MDMA is thus very different from pharmacological approaches normally used in therapy. June Riedlinger gave "A Pharmacist7 s Perspective" on this matter in the July-September 1985 Journal of Psychoactive Drugs ... 

A good general book on psychoactive drugs is Uppers, Downers, All Arounders Physical and Mental Effects of Drugs of Abuse by Darryl S. Inaba and William E. Cohen (Ashland, Oregon Cine-med, 1990). See also the pamphlet Drugs of Abuse An Introduction to Their Actions ed Potential Hazards (9th revised edition, 1990) by Samuel Irwin, distributed by the Do It Now Foundation (P.O. Box 27568, Tempe, Arizona 85285). 

Further, it is clear that, as with any psychoactive drug, the pleasant feelings alcohol can provide depend as much on set and setting as on pharmacological action. The same amount of wine that makes someone pleasantly high at a party may make a depressed person in a lonely room even more depressed. 

All psychoactive drugs exert their actions on individual neurons in the brain more specifically, drugs act on the contact points, or synapses, between cells. The synapse is the site of many important brain proteins, including ion channels (discussed later in this chapter) that are responsible for the rapid transmission of information between neurons. 

All psychoactive drugs produce their effects by action on the nervous system-primarily by altering normal brain function. 

Kaufman, Joyce J., "Quantum Chemical and Theoretical Techniques for the Understanding of Action of Psychoactive Drugs and Narcotic Agents," International Conference on Computers in Chemical Research and Education, Ljubljana, Yugoslavia, July 12-17, 1973, in Comput. Chem. Res. Educ. Proc. (1973),... 

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