Editorial

Any healthcare professional involved in the treatment of schizophrenia cannot help but be astounded by the effects that clozapine sometimes brings about. Many will also have observed that in those who benefit from clozapine, there is occasionally a gradual emergence of obsessive-compulsive symptoms as psychotic symptoms abate. In this issue, Stephen Bleakley and co-workers find little support for this clinical observation, showing that obsessive-compulsive symptoms are just as common before clozapine as after its initiation. Only three of 49 patients developed entirely new symptoms after starting clozapine.

A drug often used alongside clozapine, as well as an antipsychotic in its own right, is amisulpride. With its narrow range of pharmacological activities, amisulpride has a reputation as a well tolerated drug with few adverse effects. Kotan and colleagues demonstrate that amisulpride has a low potential for weight gain but is associated with important increases in total cholesterol concentration and substantial increases in prolactin. Changes in prolactin were shown to be more marked in women and were apparent from the first week of treatment, broadly mirroring changes in symptom scores.

Selective Serotonin Re-uptake Inhibitors (SSRIs) are now the mainstay of treatment for depression around the world. Their use is however somewhat inhibited by their anti-platelet effect which may be linked to an increased risk of gastro-intestinal and other bleeding. This effect also limits or even precludes their use in those taking anti-platelet or anticoagulant drugs. Gawande and colleagues have carefully examined the coagulopathic effects of fluoxetine and escitalopram and showed that escitalopram seemed to have no effect on coagulation parameters whilst fluoxetine increased bleeding time only to a very small extent. This is one of the first studies to show any difference between individual SSRIs on coagulation parameters.

An alternative to SSRIs, particularly where SSRIs are contra-indicated, is the melatonin agonist agomelatine. As a relatively new drug, little is known about its effects outside the rarefied environment of clinical trials. Julie Langan and colleagues report on their observations in 48 patients treatment in normal clinical practice. Agomelatine was clearly effective and well tolerated although its use in treatment-resistant patients (a practice that is the scourge of nearly all new drugs in psychiatry) was considerably less successful.

The recently introduced atypical antipsychotic asenapine has a unique range of actions at several serotonin receptor sites. Gavin Reynolds examines this receptor pharmacology, which provides explanations for the drug’s favourable tolerability profile. Although it binds to the same Histamine H1, alpha adrenergic and 5-HT2C receptors as olanzapine, asenapine has a much lower propensity for weight gain, indicating subtle differences in its 5-HT2C-mediated effects, or perhaps other protective receptor mechanisms. Understanding these differences will aid the future improvements in therapy for bipolar disorder and other psychoses.