Levomepromazine for schizophrenia

[Antipsychotic Treatment of the Adult Patient in the Acute Phase of Schizophrenia]

OBJECTIVES

To determine the efficacy and safety of different antipsychotic drugs in the management of patients diagnosed with schizophrenia in the acute phase. To formulate evidence-based recommendations on the antipsychotic (AP) drug management strategies for the treatment of the adult diagnosed with schizophrenia in the acute phase.

METHOD

Clinical practice guidelines were prepared, using the guidelines of the Methodology Guide of the Ministry of Health and Social Protection, in order to identify, synthesise, and evaluate the evidence and formulate recommendations as regards the management and follow-up of adult patients diagnosed with schizophrenia. The evidence of the NICE 82 guideline was adopted and updated, which answered the question on the management of the acute phase of adults with a diagnosis of schizophrenia. The evidence and its level were presented to the Guideline Development Group (GDG) in order to formulate recommendations following the methodology proposed by the GRADE approach.

RESULTS

Clozapine, olanzapine, risperidone, ziprasidone, amisulpride, paliperidone, haloperidol, quetiapine, and aripiprazole were more effective than placebo for the majority of psychotic symptoms and the abandonment of treatment, but asenapine was not. Paliperidone, risperidone, quetiapine, clozapine, and olanzapine showed significant increases in weight compared to placebo. Haloperidol, risperidone, ziprasidone, and paliperidone had a higher risk of extrapyramidal symptoms than placebo. There was a significant risk of sedation or drowsiness with, risperidone, haloperidol, ziprasidone, quetiapine, olanzapine, and clozapine in the comparisons with placebo. Of the results of the comparisons between AP, it was shown that clozapine and paliperidone had a clinically significant effect compared to haloperidol and quetiapine, respectively. Olanzapine and risperidone had a lower risk of abandoning the treatment in general, and due to adverse reactions in two comparisons of each one, haloperidol was the drug with more risk of abandoning due to adverse effects, followed by clozapine. Amisulpride, haloperidol and ziprasidone had favourable results as regards weight increase in several comparisons. Aripiprazole and paliperidone obtained a higher number of favourable results as regards sedation, and all the atypical drugs (except paliperidone) had a lower risk than the use of anti-parkinsonian drugs. Of the evidence from observational studies, it was found that, in subjects with risk factors for diabetes, such as age, hypertension, and dyslipidaemia, the initial treatment and current treatment with olanzapine, as well as current treatment with clozapine, may promote the development of this disease.

CONCLUSION

Although it is imperative to prescribe an antipsychotic for treatment of the acute phase, the selection of the drug depends on the particular clinical condition of each patient and their collateral effects profile.

Photooxidation mechanism of levomepromazine in different solvents

Unwanted photoinduced responses are well-known adverse effects of most promazine drugs, including levomepromazine (LPZ, Levoprome(®) or Nozinan(®)). This drug is indicated in psychiatry primarily for the treatment of schizophrenia and other schizoaffective disorders. Levomepromazine's particular sedative properties make it especially fit for use in psychiatric intensive care. Nevertheless, it is photolabile under UV-A and UV-B light in aerobic conditions resulting in the formation of its sulfoxide. The LPZ photochemistry in acetonitrile (MeCN) is completely different from that in methanol (MeOH) and phosphate buffer solutions (PBS, pH = 7.4). The major photoproduct in PBS and MeOH under aerobic conditions is levomepromazine sulfoxide (LPZSO), although the amount is considerably higher in the aqueous environment. The corresponding main photoproduct in MeCN could not be characterized. The destruction quantum yields of LPZ in PBS, MeOH and MeCN are 0.13, 0.02 and <10(-3), respectively. It is further demonstrated that LPZSO does not form by the reaction of singlet oxygen with ground-state LPZ. This oxidation product is actually produced by the reaction of the cation radical of LPZ (LPZ·(+)) with molecular oxygen. This cation radical in turn, is produced by an electron transfer process between the (3) LPZ* and ground-state molecular oxygen.