Monitoring plasma levels of fluphenazine during chronic therapy with fluphenazine decanoate

This study was conducted to examine the interpatient variability in steady–state plasma concentrations of fluphenazine by repeat depot intramuscular administration, and to determine the relationship between these concentrations and clinical state. Steady–state pre–dose concentrations of fluphenazine in plasma were measured using a sensitive and specific gas chromatography/mass spectrometry (GC/MS) assay in 24 patients with schizophrenia who were receiving continuous treatment with depot intramuscular fluphenazine decanoate. Clinical response was measured using the Andreasen Scale for positive and negative symptoms. Steady–state plasma concentrations of fluphenazine ranged from undetectable (< 0–l ng/ml) to 27-9 ng/ml, with a median of 0–5 ng/ml. No significant associations were found between plasma concentration and dosage, or age and sex of the patient. Steady–state plasma concentrations in patients taking anticholinergic agents were significantly higher than in patients not receiving such drugs (P < 0–05 by MannWhitney U–test). Poorer control, expressed as the sum of the negative symptom scores or the sum of the positive and negative symptom scores, was related to higher log transformed plasma concentrations of fluphenazine and higher fluphenazine decanoate dosage. The log transformed plasma concentrations of fluphenazine and the fluphenazine decanoate dosages were weakly related. Patients receiving another antipsychotic drug in addition to fluphenazine decanoate tended to have poorer clinical control and higher dosages of fluphenazine decanoate. These results indicate the useful role that plasma level monitoring can fulfil in identifying patients who are therapy–resistant despite high plasma levels.     

Drug-related admissions to an Australian hospital

This study was conducted to determine the prevalence of drug-related hospital admissions in southern Tasmania, Australia. The causes of consecutive admissions to medical wards of the Royal Hobart Hospital were reviewed. Comprehensive data were collected over a 10-week period on 691 admissions (median age: 67 years and range: 11–97 years; 50.8% males). Sixty-eight (9-8%) of the admissions were classified as being either probably or definitely drug-related. Most of these admissions were attributable to intentional overdose (38.2%) or an adverse drug reaction (30.9%). The overdoses often involved benzodiazepines or antipsychotics. Gastrointestinal bleeding related to the use of nonsteroidal anti-inflammatory drugs was the most common adverse drug reaction (38.1% of all reactions). Other drug-related admission categories were poor compliance (14.7%), dosage decrease or therapy cessation by a doctor producing an exacerbation of symptoms (7.4%), substance abuse (4.4%) and drug interaction (4.4%). Patients with a drug-related admission were, on average, younger than the other medical admissions, with no significant difference in gender. Patients admitted due to an overdose or substance abuse were younger than other drug-related admissions and non-drug related admissions. In conclusion, this study has determined that almost 10% of medical admissions to the hospital are drug-related and it is estimated that 40 to 50 elderly people are admitted each year suffering from gastrointestinal bleeding related to nonsteroidal anti-inflammatory drugs.     

Prescribing trends for anti-asthma drugs in Tasmania following the National Asthma Campaign

In recent years there has been a change in asthma pharmacotherapy, with considerably greater emphasis placed on the use of preventive therapy (inhaled corticosteroids and sodium cromoglycate) and less reliance on bronchodilator therapy. This study examined Tasmanian prescribing trends to determine whether the recommended changes in the treatment of asthma had transpired into practice and to compare the State prescribing trends with national Australian data. Computerized dispensing records, consisting of summarized monthly lists of all drugs dispensed, from almost one-third of all the community pharmacies within the State were retrospectively collected at intervals of 6 months between 1991 and 1994. Anti-asthma drugs were grouped into β-agonists, inhaled corticosteroids, theophylline, ipratropium bromide and sodium cromoglycate, and quantities were converted to defined daily doses (DDDs)/ 1000 population/day, by extrapolation to the entire Tasmanian population. The Tasmanian data were compared with estimated national dispensing data for anti-asthma drugs provided by the Drug Utilization Subcommittee of the Pharmaceutical Benefits Advisory Committee. Tasmanian prescribing was generally similar to the national data, with large rises in the prescribing of inhaled corticosteroids (61% increase), ipratropium bromide (138% increase) and sodium cromoglycate (52% increase), and a decline in theophylline usage (43% decrease) over the period of the study. The prescribing of β-agonists remained fairly stable over the period of the study, while there was a marked decrease in the ratio of dispensed DDDs of β-agonists: inhaled corticosteroids (from 2.9 to 1.7). The overall usage of anti-asthma medication in Tasmania was found to be significantly higher than the national data for 1991 and 1992, with an April 1994 level of 74.7 DDD/1000 population/day (an increase of 6% from April 1991). Tasmanian and national prescribing of anti-asthma drugs appears to have changed in line with current management guidelines, with greater emphasis on the use of inhaled corticosteroids. More attention could also be given to the prescribing of anti-allergy preventive drugs.     

Review of the initiation of anticoagulant therapy

The objective was to retrospectively study the initiation of anticoagulant therapy in inpatients of the two major teaching hospitals in Tasmania, Australia. The medical records of a random sample of patients with an admission diagnosis of deep venous thrombosis (DVT) or pulmonary embolism (PE) during the period February 1992 to June 1994 were studied, to examine therapeutic issues including (i) the time taken after commencing heparin to achieve a therapeutic activated partial thromboplastin time (APTT), (ii) when warfarin was commenced, (iii) the time taken after commencing warfarin to achieve a therapeutic International Normalized Ratio (INR), and (iv) the degree of anticoagulant control at the time of discharge from hospital. The medical records of 99 patients (median age: 65 years and range: 16–93 years; 52 females) were studied. Heparin was generally commenced within 4 h of admission to hospital. The median duration of heparin therapy was 5 days (range: 2–26 days). The median number of APTTs performed per patient was 6 (range: 1–24), with most results (60%) being below the optimum range. Warfarin was commenced from day 1 of hospitalization in only 34% of patients. The INR was within the therapeutic range in only 29% of cases when heparin was ceased. The median time taken to achieve a therapeutic INR after starting warfarin was 3 days (range: 1–15 days). The median number of INRs performed per patient was 5 (range: 1–29), with most results (51%) being below the optimum range. The INR was within the therapeutic range in only 55% of cases at discharge. An adverse outcome (bleeding or further clotting) was experienced by 19% of patients. This study has revealed considerable scope for improvement in some aspects of the initiation of anticoagulant therapy.