Low-dose caveat for schizophrenia.

Low-dose caveat for schizophrenia

Low doses of antipsychotic drugs--aslittle as one-tenth of conventional doses-- have recently been touted as an effective way to improve the condition of many schizophrenic patients while decreasing the risk of drug-induced movement disorders such as tardive dyskinesia (SN: 11/10/84, p.297). But according to a report in the June ARCHIVES OF GENERAL PSYCHIATRY, the low-dose approach also increases the risk that schizophrenic symptoms will worsen, particularly during the second year of treatment.

The implication for psychiatrists, sayStephen R. Marder and his colleagues of West Los Angeles Veterans Administration Medical Center, is that low doses of antipsychotics, also called neuroleptics, are useful but should be prescribed only if a patient can be closely monitored for eventual symptom flare-ups that can lead to a return of full-blown schizophrenia.

The researchers followed 68 men whohad been diagnosed as schizophrenic for more than 10 years. Each subject received an injection of the long-acting neuroleptic fluphenazine decanoate every two weeks. In about half the cases, a conventional dose was used; the rest of the men were given one-fifth the conventional dose.

During the first year of treatment,about two-thirds of both groups of patients displayed no significant worsening of symptoms such as disorganized thinking, hallucinations, hostility and suspiciousness. In the second year, the condition of the conventional-dose group remained steady while symptoms were kept in check for only about one-third of the low-dose patients.

When as much as twice the originaldose was administered after the first signs of a flare-up, say the researchers, a substantial portion of both low- and conventional-dose patients improved. At the end of two years, higher drug levels eased the symptoms of about two-thirds of the conventional-dose patients whose condition had worsened, and the success rate was slightly less for the low-dose patients.

Patients given the higher dose reportedmore restlessness and discomfort in the first six months of treatment, note the investigators, and six of them dropped out of the study.

The researchers conclude that "it isunlikely that there will ever be a simple formula' for selecting the best neuroleptic dosage for individual schizophrenics.