Postural hypotension in chronically medicated schizophrenics.

Blood pressure readings at rest and on standing in 196 chronic schizophrenic patients on stable long-term antipsychotic treatment were compared with those in unmedicated healthy controls. Patients recorded significantly lower resting blood pressure and significantly higher prevalence of postural hypotension than controls. The prevalence of postural hypotension in patients was 77% at 1 minute and 16.8% at 3 minutes after standing compared with absence of postural hypotension in controls at both time points. Prevalence of postural hypotension was unaffected by age or sex and was poorly correlated with drug dose, except in young patients. alpha 1-Receptor binding affinity of antipsychotic drugs was not predictive of postural hypotension. The possible significance of such persistent postural hypotension in chronically medicated patients is discussed.