The generic alternative in schizophrenia: opportunity or threat?
Pharmacological treatment of schizophrenia often requires careful dosage titration to achieve satisfactory symptom control whilst minimising the risk of adverse effects. Relapses requiring hospitalisation are an important potential source of additional cost for the health service and any inadequate symptom control increases the indirect costs of schizophrenia relating to, for example, the need for sheltered accommodation or intensive social services support. The availability of generic drugs is widely regarded as an opportunity to reduce expenditure on drug costs and deploy limited resources more widely and effectively. However, generic drugs may differ from branded drugs in their formulation and may not show precise bioequivalence with the branded product. This may have consequences for the pharmacokinetic profile of the generic drug. A higher maximum plasma concentration (C(max)) could lead to increased or emergent adverse effects, whereas a decreased absorption or minimum plasma concentration (C(min)) may result in a reduced therapeutic effect. For example, plasma levels of clozapine are critical to therapeutic response. Symptom aggravation occurred in approximately 10% of patients switched from branded to generic clozapine in a small, randomised, crossover study. Patients with schizophrenia may also show suspicion and hostility regarding their treatment. This may result in unwillingness to take an unfamiliar medication and decreased compliance, thus increasing the risk of a relapse. Thus, great care should be taken by psychiatrists when switching patients with schizophrenia from branded to generic antipsychotic drugs; this entails monitoring clinical outcome closely and adjusting the treatment in case of symptom aggravation or emergence of adverse effects.
Nuss
Philippe
P
Psychiatry Department, Hôpital St Antoine, Paris 75012, France. philippe.nuss@sat.at-hop-paris.fr
Taylor
David
D
De Hert
Marc
M
Hummer
Martina
M
D014150:Antipsychotic Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D016568:Drugs, Generic / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006801:Humans; D010342:Patient Acceptance of Health Care / Q000523:psychology; D011634:Public Health; D012559:Schizophrenia / Q000188:drug therapy*; D013810:Therapeutic Equivalency; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D016568:Drugs, Generic