Antipsychotic , atypical

Atypical antipsychotics cause fewer EPS than do conventional antipsychotics. Clozapine and quetiapine are the least likely to cause EPS and are therefore recommended for treatment of psychosis in patients with Parkinson s disease. With the notable exception of risperidone, atypical antipsychotics cause substantially less hyperprolactinemia than do conventional antipsychotics. Weight gain is a side effect of all atypical antipsychotics except ziprasidone and aripiprazole. Concerns about cardiac conduction delay with ziprasidone therapy exist and warrant consideration in patients who have 

Traditional antipsychotics are associated with more side effects than newer counterparts, including an in- 

Traditional agents are also somewhat less predictable, and there tends to be more patient-to-patient variability in the beneficial (antipsychotic) effects of these medications.18 Newer atypical drugs may be somewhat safer and more predictable, and these agents are described next. 

Several newer antipsychotic medications have been developed that seem different or atypical, compared with their predecessors. These agents include clozapine (Clozaril), risperidone (Risperdal), and several others listed in Tables 8-1 and 8-2. Although there is some debate about what exactly defines these drugs as atypical, the most distinguishing feature is that they have a much better side-effect profile, including a decreased risk of producing extrapyramidal (motor) side effects.17,45,57 

Generic Name Aripiprazole Trade Name Abilify Usual Dosage Range (mg/d) 10-30 Maximum recommended dosage (mg/d) 30 

Antipsychotics are usually administered orally. During the acute stage of a psychotic episode, the daily dosage is often divided into three or four equal amounts. Maintenance doses are usually lower and can often be administered once each day. Under certain conditions, antipsychotics can be given intramuscularly. 

---

More interesting is the mechanism of action of atypical antipsychotics, particularly clo2apine (60). It is also probably the least selective antipsychotic used in the clinic, having high affinity for numerous receptors including 5-HT2, 5-HT, and dopamine D, D3) and receptors ... 

Risperidone (11) is a new type of an atypical antipsychotic with relatively pronounced effects on negative symptoms and low extrapyramidal side... 

Risperidone (11) was also included among a a 1-adrenergic receptor antagonists to study a quantitative structure-activity relationship (99BMC2437). A pharmacophore model for atypical antipsychotics, including 11, was established (00MI41). An increased plasma level of 11 and 9-hydroxyrisperidone (12) was observed in combination with paroxetine (01 MI 13). The effect of vanlafaxine on the pharmacokinetics of 11 was reported (99MI13). 

Atypical antipsychotic diugs Novel antipsychotic diugs serotonin/dopamine antagonists 5HT2A/D2 antagonists. 

Kapur S, Seeman P (2001) Does fast dissociation from the dopamine D2 receptor explain the action of atypical antipsychotics A new hypothesis. Am J Psychiatry 158 360-369... 

Kapur S, Remington G (2001) Atypical antipsychotics new directions and challenges in the treatment of schizophrenia. Annu Rev Med 52 503-517... 

McLellan AT, Kushner H, Metzger D, et al The fifth edition of the Addiction Severity Index. J Subst Abuse Treat 9 199—213, 1992 Mechanic JA, Maynard BT, Holloway FA Treatment with the atypical antipsychotic, olanzapine, prevents the expression of amphetamine-induced place conditioning in the rat. Prog Nemopsychopharmacol Biol Psychiatry 27 43—54, 2003... 

George TP, Ziedonis DM, Feingold A, et al Nicotine transdermal patch and atypical antipsychotic medications for smoking cessation in schizophrenia. Am J Psychiatry 157 1835-1842, 2000... 

Head-to-head comparisons of atypical antipsychotic drugs... 

Considerable funds, time and effort have been expended on pharmacoeconomic evaluation of atypical antipsychotic drugs and many journal... 

A search of Medline, EMBASE and PsycLIT was conducted in August 2000, using the following terms Amisulpride, clozapine, olanzapine, risperidone, sertindole, zotepine, ziprasidone, economics, healthcare, costs. All manufacturers of atypical antipsychotic drugs were contacted in April 2000 and asked to supply primary reference data on their product, and all companies had complied with this request by August 2000. A further manual search was conducted of files and journals kept in the National Centre for Information on Psychotropics at the Maudsley Hospital. Reference sections from all retrieved papers were scrutinized for further relevant references. 

Issues in the design of studies for the economic evaluation of new atypical antipsychotics the ESTO study. /Mem Health Polity Econ 1, 15—22. 

Changes in perceived physical and mental health status of a schizophrenia patient population following initiation of a conventional or an atypical antipsychotic medication. Poster presented at the American Psychiatric Association Annual Meeting, Toronto, June 1998. 

The advent of novel atypical antipsychotic drugs has sharpened the debate in the UK about the cost burden of schizophrenia to the National Health Service (NHS) and the relative cost-effectiveness of these drugs. Schizophrenia has a prevalence of about 0.5% and a lifetime risk of 1%. Because the disease affects adolescents and has a lifetime course associated with a high degree of hospital and social... 

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... 

Principally because of its efficacy/tolerability ratio, prescriptions for quetiapine are growing faster than for any other atypical antipsychotic drug at present (personal communication, Astra Zeneca). 

Azorin JM (2000). Acute phase of schizophrenia. Impact of atypical antipsychotics. Int Clin PsychopharmacolX (suppl. 4), 11—14. 

---