Adverse drug reactions in women appear to occur at a higher rate in both hospital and community settings. Among the mechanisms which may account for the increased toxicity and adverse drug reactions in women, pharmacogenetic factors play an important role. Therapeutic drug monitoring of olanzapine has revealed tendencies for higher concentrations in women suggesting that metabolism of the drug may be gender-specific. Cytochrome P450 CYPIA2 is involved in the breakdown of olanzapine (Rao et al., 2001) and has been shown to exhibit a sexual dimorphism (Ou-Yang et al., 2000). We investigated CYP1A2 variants in a naturalistic study of schizophrenic inpatients who underwent therapeutic drug monitoring for olanzapine. Clinical implications for this antipsychotic compound are discussed.
Methylphenidate (MPH) is a prescription stimulant used to treat attention-deficit hyperactivity disorder. MPH is currently the preferred substance among most intravenous (i.v.) substance users in Iceland. Four types of MPH preparations were available in Iceland at the time of study: Immediate-release (IR), sustained-release (SR), osmotic controlled-release oral delivery (OROS) tablet and osmotic-controlled release (OCR). MPH OROS has previously been rated the least desirable by i.v. users and we hypothesized that this was associated with difficulty of disintegrating MPH from OROS formulation. The aim of the study was to measure the amount of MPH and the viscosity of the disintegrated solutions that were made from the four MPH formulations by four i.v.-users and non-users.A convenience sample of four i.v. substance users and 12 non-users. Non-users imitated the methods applied by experienced i.v. substance users for disintegrated MPH formulations.Both groups managed to disintegrate over 50% of MPH from IR and SR formulations but only 20% from OROS (p < 0.0001). The viscosity of the disintegrated MPH was significantly higher for MPH OROS and MPH OCR and the preparation was significantly more time-consuming than for the other MPH samples. No differences were observed between users and non-users.To our knowledge, this is the first investigation of viscosity and the amount of disintegrated MPH from prescription drugs for i.v. use. The results indicate that the ease of disintegration, amount of MPH and viscosity may explain the difference in popularity for i.v. use between different MPH formulations.
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hSKCa3 is a neuronal small conductance calcium-activated potassium channel, which contains a polyglutamine tract, encoded by a polymorphic CAG repeat in the gene. Since an association between longer alleles of this CAG repeat and bipolar disorder or schizophrenia has been reported, we genotyped the polymorphic CAG repeat in 91 German family trios of patients with bipolar disorder I and used the transmission disequilibrium test (TDT) to test for association. Applying a dichotomized model (less than or equal to 19 or >19 CAG triplets), we found no evidence for an association of longer alleles with bipolar disorder (TDT = 0.75, P = 0.386). Regarding the whole range of alleles, there was no preference in transmitting the larger of the two observed alleles from parents to the affected offspring. In parallel we performed an independent case-control study on German patients with bipolar disorder and schizophrenia. Again,ve did not detect an overrepresentation of longer CAG repeats in patients. Thus, our data do not support the hypothesis that longer CAG repeats in the hSkCa3 gene contribute to the susceptibility for bipolar disorder and schizophrenia. (C) 1999 Lippincott Williams & Wilkins.