Drug Interactions between pergolide and quetiapine

GENERALLY AVOID: Agents with antidopaminergic activity such as quetiapine and clozapine may antagonize the pharmacologic effects of dopaminergic drugs, and vice versa. Quetiapine and clozapine may cause extrapyramidal reactions (i.e., acute dystonic reactions, tardive dyskinesia, akathisia, Parkinson-like symptoms) due to antidopaminergic effects. In addition, the central nervous system depressant and hypotensive effects of these agents may be additively or synergistically increased when taken together. However, some authorities have approved the use of clozapine in patients with psychosis in Parkinson's disease (PD) when other treatment strategies have failed (UK), and quetiapine is considered as possibly effective in the treatment of psychosis in PD patients by several authorities, although this remains an off-label use.

MANAGEMENT: Concomitant use of dopaminergic drugs with antidopaminergic agents such as clozapine or quetiapine should generally be avoided. Patients should be alerted to the possibility of excessive drowsiness and monitored for potentially diminished therapeutic response to both treatments. Patients treated for PD should generally avoid antidopaminergic agents, since these agents may cause extrapyramidal reactions and exacerbate the symptoms of PD. Consult the manufacturer's labeling and local guidelines for specific recommendations. When treatment for neuroleptic-induced extrapyramidal symptoms is required, anticholinergic anti-parkinsonian agents should be used in preference to levodopa. Likewise, patients with a major psychotic disorder should ordinarily not be treated with dopaminergic drugs because of the risk of exacerbating the psychosis with an increase in central dopaminergic tone.