Antidepressants psychoactive drugs

Viesselman, J.O. (1999) Antidepressant and antimanic drugs. In Werry, J.S. and Aman, M.G., eds. Practitioner s Guide to Psychoactive Drugs for Children and Adolescents, 2nd ed. New York Plenum Medical, pp. 249-296. 

Tanaka E, Hisawa S. Clinically significant pharmacokinetic drug interactions with psychoactive drugs antidepressants and antipsychotics and the cytochrome P450 system. J Clin Pharm Ther 1999 24 7-16. 

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. 

The antidepressants have not been found to effect judgment and thinking as some psychoactive drugs may. The antidepressants will relieve the symptoms of depression and those of the other psychological problems as mentioned above. The antidepressants will make it possible for people with depression to resume a normal life, such as returning to work and school. They will help people get over their feelings of worthlessness and assist them in social functioning. 

Psychoactive drugs, including psychiatric drugs, vary in their toxicity. However, all of the major categories of psychiatric drugs—antidepressants, stimulants, tranquilizers (antianxiety drugs), mood stabilizers, and anti-psychotics—are neurotoxic. They poison neurons, and sometimes destroy them. 

M Adamczyk, et al. Immunoassay reagents for psychoactive drugs. Part 3. Removal of phenothiazine interferences in the quantification of tricyclic antidepressants. Ther Drug Monit 15 436, 1993. 

Metabolism converts a lipophilic molecule into a more hydrophilic (water-loving) metabolite that can be excreted in urine by the kidneys. In the majority of cases the drug is detoxified, or made pharmacologically inactive by this metabolic breakdown. However, a few drugs need to be metabolised to become psychoactive for instance, the sedative-hypnotic chloral hydrate is converted to the active metabolite trichloroethanol. In this case the parent molecule is referred to as a prodrug. With many drugs, both the parent compound and its metabolites are psychoactive. An example of this is the tricyclic antidepressant imipramine which is metabolised to desipramine, with... 

Many different drug classes have shown to cause hypotension and orthostatic reactions and drugs for cardiovascular conditions, psychoactive medicines and polypharmacy, can all have this side effect (Box 5.15). Among the most frequently used drugs in the elderly are diuretics, ACE-inhibitors, angiotensin II antagonists, calcium channel blockers and antidepressants. 

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