Antipsychotic agents/drugs

S.C. Dilasaver, Withdrawal phenomena associated with antidepressant and antipsychotic agents. Drug Safety 10 103-114, 1994. 

Simpson GM, Pi EH, Sramek JJ. Adverse effects of antipsychotic agents. Drugs 1981 21 138-151. 

Although atypical antipsychotic agents may cost several times as much as traditional antipsychotics, drug costs in schizophrenia account for only 1-4% of the total treatment cost (Knapp, 1997). The argument then is that a small increase in drug costs— say to 10% of total cost—may result in disproportionate savings in the highly expensive direct hospital costs, if clinical trial... 

Murray, M. (2006). Role of CYP pharmacogenetics and drug-drug interactions in the efficacy and safety of atypical and other antipsychotic agents. /. Pharm. Pharmacol, 58, 871— 85. 

Examples abound regarding the role of serendipity in the discovery of new therapeutic approaches, which on closer examination usually turned out to be the result of clinicians paying attention to unexpected clinical effects rather than discounting them. For example, lithium was tried first for hypertension, chlorpro-mazine was initially developed as an anesthetic, and imipramine was originally regarded as an antihistamine and an antipsychotic agent. Without astute clinical observations, these drugs would not have found their niche, nor would clozapine have been revived for the benefit of millions of the most difficult to treat schizophrenic patients. Other examples include the expanded indications of newer... 

To further illustrate the diversity of hydrolytic opening reactions, we turn our attention to an isothiazole ring as found in the antipsychotic agent ziprasidone (11.129). This drug is subject to various reactions of oxidation and reduction, but also undergoes hydrolytic cleavage of the C=N bond of the isothiazole ring. Evidence for this reaction was afforded by detection of radioactive metabolite 11.130, a sulfonamide, in the urine of patients dosed... 

It is of note that the two drugs ushered in the new era of psychopharmacology. The advent of a host of synthetic antipsychotic agents has diminished the importance of reserpine for this indication. The agent is still frequently prescribed in the treatment of hypertension, as are its closely related congener, res-clnnamine (31), and the semisynthetic compound syrosingopine (32). 

The pharmacological action of antipsychotic agents is very complicated. Besides the ability to change behavior, these drugs also have a number of other central and peripheral... 

See the Antipsychotic Agents monograph for drug interactions that relate to promethazine. 

There are some clinically important pharmacodynamic drug-drug interactions to be mentioned. Antipsychotics will potentiate the central depressant effects of sedatives and of alcohol. They will also increase the risk of respiratory-depressant effects of opiates. Inducers of drug metabolic enzymes like for example rifampicin and several antiepileptics, may increase the elimination rate of antipsychotic agents and thus decrease their efficacy. 

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