Long-term fluphenazine decanoate maintenance dosage requirements of chronic schizophrenic patients

Risk Factors for Psychotic Relapse After Dose Reduction or Discontinuation of Antipsychotics in Patients With Chronic Schizophrenia: A Systematic Review and Meta-analysis

High doses of antipsychotics in patients with chronic schizophrenia might lead to more severe side effects and possibly hamper recovery, but dose reduction carries the risk of psychotic relapse. It would be helpful to establish risk factors for relapse during dose reduction. We systematically searched MEDLINE, EMBASE, and PsycINFO from January 1950 through June 2019 and reviewed studies that reported on relapse rates (event rates [ERs]) after dose reduction or discontinuation of antipsychotics in cohorts of patients with chronic schizophrenia. We calculated ERs (with 95% CIs) per person-year and sought to identify potential risk factors, such as patient characteristics, dose reduction/discontinuation characteristics, and study characteristics. Of 165 publications, 40 describing dose reduction or discontinuation in 46 cohorts (1677 patients) were included. The pooled ER for psychotic relapse was 0.55 (95% CI 0.46–0.65) per person-year. The ER was significantly higher in inpatients, patients with a shorter duration of illness, patients in whom antipsychotics were discontinued or in whom the dose was reduced to less than 5 mg haloperidol equivalent, studies with a short follow-up or published before 1990, and studies in which relapse was based on clinical judgment (ie, rating scales were not used). Clinicians should consider several robust risk factors for psychotic relapse in case of dose reduction in chronic schizophrenia.

Psychopharmacology and adverse effects of antipsychotic long-acting injections: a review

BACKGROUND

Depot antipsychotics are widely used in clinical practice. Long-acting formulations of second-generation antipsychotics are now being developed and introduced.

AIMS

To review the pharmacology, pharmacokinetics and adverse effect profiles of currently available antipsychotic long-acting injections (LAIs).

METHOD

The psychopharmacological properties of first- and second-generation antipsychotic LAIs are reviewed using data available up to October 2008.

RESULTS

First-generation antipsychotic (FGA) LAIs are associated with a high rate of acute and chronic movement disorders. Risperidone LAI is better tolerated in this respect, but is associated with hyperprolactinaemia and weight gain. Olanzapine LAI causes weight gain and other metabolic effects but appears not to be associated with an important incidence of movement disorders.

CONCLUSIONS

Dosing of LAIs is complicated by delayed release of drug, changes in plasma levels without change in dose, and by the lack of data establishing clear dose requirements. All LAIs offer the prospect of assured adherence (although patients may still default on treatment) but their use is complicated by adverse effects, complex pharmacokinetics and confusion over dose-response relationships.

Spontaneous and drug-induced movement disorders in schizophrenia

The extrapyramidal side-effects (EPS) of conventional neuroleptics are widely recognized. However, a substantial number of drug-naïve patients exhibit movement disorders which could be mistaken for EPS if drug therapy were started without a careful baseline assessment. Patients' experience of EPS during their first exposure to antipsychotic medication can have lasting effects on their attitudes to medication and compliance. Unmedicated, approximately 60% of patients will relapse in the first year after resolution of an acute psychotic episode, whereas prophylactic medication can reduce the relapse rate to less than 20%. The conventional neuroleptics produce antipsychotic effects at doses which differ little from those that induce EPS, and although anticholinergic medication helps to reduce the severity of EPS, it also causes side-effects, e.g. constipation, blurred vision, retention of urine, dry mouth and disturbances of sexual function. More importantly, anticholinergic drugs may worsen the psychosis and impair memory. Low or intermittent dose strategies with conventional neuroleptics may give patients relief from EPS, but they increase the relapse risk, and may also increase the risk of tardive dyskinesia. The serotonin-dopamine antagonist (SDA) antipsychotics, such as risperidone, produce both significant antipsychotic effects at doses which are lower than those that cause EPS, and also a lower level of EPS compared with conventional drugs. Clinical trials have shown that risperidone is effective in first-episode schizophrenia. In these trials the same doses were used as in chronic patients. However, clinical experience in Canada since the drug became generally available in 1993 suggests that first-episode patients require lower doses of risperidone than chronically ill patients who have had several acute psychotic episodes. More than 3 years of use has made it clear that risperidone should be seriously considered in first-episode patients, as it offers an opportunity to treat psychosis with minimal EPS. This in turn should lead to better compliance and a lower long-term relapse rate.

Factors affecting rehospitalisation rates of chronic schizophrenic patients living in the community

Eighty-eight [corrected] patients selected from a depot neuroleptic clinic in the hospital outpatients department were assessed clinically on various demographic and clinical variables with a view to determining the factors that may contribute to high rates of rehospitalisation amongst schizophrenics in remission. It was found that rehospitalisation rates during the preceding 5 years correlated with an early age of onset of illness, severity of positive and affective symptoms, current neuroleptic dose and total AIMS score, all reflecting the severity of underlying psychotic disorder and the neuroleptic treatment required to treat the psychosis. Poor compliance with neuroleptic prophylaxis was not found to be of importance in contributing to high relapse rates in this sample. It was concluded that patients who repeatedly relapse may do so because of the clinical characteristics of their illness.

Depot antipsychotic drugs. Place in therapy

The pharmacokinetics of depot antipsychotic medications are such that an intramuscular injection given at intervals of from 1 to 4 weeks will produce adequate plasma concentrations that are sufficient to prevent relapse over the dosage interval. Such medication is useful in patients who do not reliably take their oral medication. The pharmacokinetics and clinical actions of various depot formulations of antipsychotic drugs have been extensively studied. Unfortunately, patients who do not reliably take their oral medications are unlikely to volunteer for controlled studies. This is because the same factors that influence a patient to not cooperate with the physician in taking the medication as prescribed will also interfere with their willingness to volunteer for research protocols. Thus, evidence from blinded controlled trials may not necessarily reflect the actual patient population at risk. We feel that particularly important evidence of efficacy of depot vs oral medication comes from mirror-image studies. In these trials, the number of hospitalisations after initiation of depot medication is compared with that observed when the patient was solely taking oral medication. Studies of this type show that depot medication substantially reduces the rate of relapse. There is considerable evidence about how long depot medications should be used. For many patients, depot medication to prevent relapse in schizophrenia should be used for the life of the patient. As the conventional antipsychotic agents are replaced by a new generation of agents, the need for depot formulations will continue, and the knowledge gained about the current formulations should transfer to future generations of drugs.

Predictors of the course of tardive dyskinesia in patients receiving neuroleptics

As many patients still require maintenance neuroleptic medication, it is important to determine what factors affect the course of tardive dyskinesia (TD) during ongoing neuroleptic treatment. In this study the data are from a series of annual examinations using the Abnormal Involuntary Movement Scale (AIMS) in a cohort of outpatients. Average neuroleptic exposure at the commencement of the examinations was 10 yr. The data on AIMS scores at successive visits are analysed using autoregressive modeling. Two hundred thirty-five patients contributed the 678 pairs of examinations. Separate analyses are reported for orofacial, limb-truncal, and total AIMS scores. Different predictor variables emerged as important for orofacial and limb-truncal dyskinesia. Age, sex, being on anticholinergic medication, and two variables describing duration of neuroleptic exposure contributed to the outcome score for total AIMS score after 1 yr.

Drug prescribing for schizophrenic out-patients on depot injections. Repeat surveys over 18 years

Serial surveys of the prescribing practices of psychiatrists for schizophrenic out-patients over 1970-88 showed important changes. During the interval 1970-83, polypharmacy and the use of multiple neuroleptics were reduced. The total dose of neuroleptics prescribed fell and the proportion administered by depot injection increased. Since 1983, however, some of these favourable trends have been reversed. Prescribing practices may also vary between teaching and non-teaching hospitals.

Double-blind comparison of half-dose and standard-dose flupenthixol decanoate in the maintenance treatment of stabilised out-patients with schizophrenia

A double-blind controlled trial of 50% dose reduction in maintenance treatment in stable out-patients with low BPRS scores and good social function shows a significantly higher relapse rate in the low-dose group at 12 months (P less than 0.05). After an interval of 24-36 months from dose reduction, 56-76% had experienced a relapse and 76-79% had resumed their former dosage. No clear advantage was shown for the lower dose in either a reduction of side-effects or improved social function, but a reduced prevalence or lower rate of symptom emergence for tardive dyskinesia was suggested.

Long-term depot maintenance of chronic schizophrenic out-patients: the seven year follow-up of the Medical Research Council fluphenazine/placebo trial. III. Relapse postponement or relapse prevention? The implications for long-term outcome

The relapse and admission histories revealed a positive correlation between number of schizophrenic episodes and time on maintenance medication, probably reflecting severity of illness. Relapse rates after drug discontinuation rose to 45% within 13 months. There were no differences of predictive value between those relapsing on or off medication. The relationship between relapse rates, drug treatment, and social outcome is complex; antipsychotic drugs may postpone relapse, and frequent relapses might inhibit improvement in social performance long after florid symptoms have been controlled by medication.

The discontinuance of maintenance neuroleptic therapy in chronic schizophrenic patients: drug and social consequences

In a prospective follow-up the outcome of 60 chronic schizophrenic patients who discontinued neuroleptic therapy after remaining stable 12-48 months was compared with controls continuing medication. Not only did the drug-discontinued patients have more relapses (P less than 0.001), but the form of relapse was both more severe and acute, resulting in differences of self-injury (P less than 0.05), anti-social behaviour (P less than 0.01), inpatient admissions (P less than 0.001), and the use of compulsory powers (P less than 0.01). In patients who relapsed, both social and work function was affected adversely for some months. Patients who remained relapse-free without drugs (20%) had a level of work and social function similar to medicated patients. At the end of 18 months the patients who discontinued depot maintenance therapy were found to have been prescribed one-third more neuroleptic drugs than controls, with a possible increase in the risk of long-term tardive dyskinesia.