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Olav Spigset

Publications and source records attributed to Olav Spigset.

64 records · Page 4Linked to original sources

Hepatic injury and pancreatitis during treatment with serotonin reuptake inhibitors: data from the World Health Organization (WHO) database of adverse drug reactions.

Severe hepatic adverse drug reactions have been occasionally reported in the literature for the selective serotonin reuptake inhibitors (SSRIs), venlafaxine and nefazodone. In addition, a few case reports have suggested a possible association between SSRI treatment and pancreatitis. To further investigate this issue, a Bayesian confidence propagation neural network (BCPNN) method was applied on the World Health Organization database of adverse drug reactions. This method identifies whether a drug/adverse drug reaction combination is reported more frequently to the database than expected on the basis of chance alone compared to general reporting in the database. A statistically significant unexpected high number of reports were found for nefazodone and hepatic injury, relative to the generality of the dataset but, for the other drug/adverse drug reaction combinations, no such association was found. The nefazodone finding is in accordance with data from other publications, suggesting that the risk of hepatic injury is increased. However, because of the nature of the BCPNN, the negative findings do not necessarily prove that there is no excess risk for hepatic injury/pancreatitis during treatment with drugs other than nefazodone. Further studies are required using alternative methodologies to demonstrate whether the selective serotonin reuptake inhibitors or venlafaxine may cause hepatic injury or pancreatitis.

Adverse Drug Reaction Reporting Systems↗

Olanzapine and venous thromboembolism.

Clozapine has recently been associated with venous thromboembolism. The aim of this study was to describe three elderly patients in whom olanzapine therapy was associated with venous thromboembolism. During a 4-month period at the same psychogeriatric clinic, three elderly patients (an 89-year-old male, a 78-year-old male and an 83-year-old female) developed deep venous thrombosis shortly after treatment with olanzapine was initiated. Two of the patients also had symptoms consistent with a diagnosis of pulmonary embolism. None had previously been diagnosed with venous thromboembolism. These cases indicate that venous thromboembolism might be associated with the use of olanzapine, at least in geriatric patients. Subjects treated with olanzapine should be monitored clinically for venous thromboembolism to ensure early detection and prompt intervention, and a possible discontinuation of treatment with olanzapine should be considered after a diagnosis of venous thromboembolism.

Aged↗

Agranulocytosis and other blood dyscrasias associated with dipyrone (metamizole).

OBJECTIVE: Agranulocytosis is a potentially lethal adverse drug reaction of dipyrone (metamizole). According to case-control studies, the frequency is low, approximately one per million users. The aim of the study was to describe the pattern of blood dyscrasias associated with dipyrone, identify possible risk factors and calculate the incidence of agranulocytosis associated with dipyrone. METHODS: All spontaneous reports of serious blood dyscrasias associated with dipyrone in Sweden were reviewed. The reports were scrutinised for additional information, including bone marrow findings. The reported incidence of agranulocytosis was estimated from total prescription sales of dipyrone. RESULTS: The reported incidence of agranulocytosis with dipyrone in Sweden was estimated to be at least 1:1439 (95% confidence interval 1:850, 1:4684) prescriptions. Ninety-two percent of the cases of blood dyscrasias occurred during the first 2 months of treatment. Additional risk factors were identified in 36% of the patients. In a total of five cases of which four were fatal, all three haematopoieses were affected according to bone marrow sample findings. Among the fatal cases, a higher proportion had bi- or tricytopenia than among the non-fatal cases ( P<0.005). CONCLUSION: Based on sales data and spontaneous reporting of adverse drug reactions in Sweden, the risk of agranulocytosis with dipyrone seems to be considerably higher than the previously estimated risks. Dipyrone is also associated with other blood dyscrasias, and the prognosis for combined dyscrasias seems to be poorer than for isolated agranulocytosis.

Adult↗

Change from the CYP2D6 extensive metabolizer to the poor metabolizer phenotype during treatment With bupropion.

Some data indicate that bupropion inhibits the cytochrome P-450 enzyme CYP2D6, but very little published data is available on the extent of this inhibition. The objective of the present study was to quantify this inhibition in a subject treated with bupropion for smoking cessation. Genotypically, the patient was a CYP2D6 homozygous extensive metabolizer (EM). His CYP2D6 phenotype was assessed using the test drug dextromethorphan before, during, and after treatment with bupropion. During treatment with bupropion, he clearly changed from the EM to the poor metabolizer (PM) phenotype. Although the results from a single patient should be interpreted with great caution, the extent of the interaction indicates that bupropion might be a CYP2D6 inhibitor as potent as the most powerful CYP2D6 inhibitors known, such as quinidine and paroxetine.

Adult↗

Genotyping of drug targets: a method to predict adverse drug reactions?

In the last decades, advances in molecular biology have led to modern pharmacogenetics, which started as a science that focused on investigating drug metabolising enzymes and genetic determinants of pharmacokinetic variability. As more evidence has become available on the structure of drug targets and the genes coding for them, increasing attention has been directed towards pharmacodynamic explanations of variability in therapeutic response as well as in the risk for adverse drug reactions. Traditionally, genetic drug safety research has focused on variations in single genes whose functions are known to be related to given adverse drug reactions. A few such examples, malignant hyperthermia, the long QT syndrome, venous thromboembolic disease, tardive dyskinesia, and drug addiction, are presented in this article. In the future, results from the Human Genome Project together with tools such as DNA microarray technology, high-output screening systems and advanced bioinformatics, will permit a more thorough elucidation than is currently possible of the genetic components of adverse drug reactions. By screening for a large number of single nucleotide polymorphisms (SNPs), SNP patterns associated with adverse drug reactions can be discovered even though the functions of the SNPs as such are completely unknown. On the basis of these findings, it can be expected that pharmacogenetic research will identify situations where a drug should be avoided in certain individuals in order to reduce the risk for adverse drug reactions. If so, it will be feasible to use molecular diagnostics to select drugs that are safe for the individual patient.

Drug-Related Side Effects and Adverse Reactions↗

Glucose intolerance with atypical antipsychotics.

BACKGROUND: Previous studies have suggested that the atypical antipsychotics clozapine and olanzapine may be associated with an increased risk of glucose intolerance and diabetes mellitus. Early studies have also suggested an association between use of conventional antipsychotics and the development of glucose intolerance. OBJECTIVE: To examine quantitatively the association between glucose intolerance including diabetes mellitus and the use of the atypical antipsychotics clozapine, olanzapine or risperidone, and to identify possible risk factors for the development of glucose intolerance during treatment with these drugs. METHODS: All reports suggestive of glucose intolerance for clozapine, olanzapine and risperidone were identified in the WHO database for adverse drug reactions. In the analyses of possible risk factors for glucose intolerance all other reports of adverse drug reactions for clozapine, olanzapine and risperidone were used as reference. Using the Bayesian Confidence Propagation Neural Network method, the strengths of the associations over time between glucose intolerance and the use of these drugs were analysed. For comparison, the strengths of the associations between glucose intolerance and the use of the conventional antipsychotics haloperidol and chlorpromazine were also analysed. RESULTS: Clozapine, olanzapine and risperidone were significantly associated with glucose intolerance. In contrast, chlorpromazine and haloperidol were not associated with glucose intolerance. For clozapine, olanzapine and risperidone grouped together, the following potential risk factors for glucose intolerance were identified: an underlying diabetic condition (odds ratio [OR] 10.22, 95% CI 8.20-12.73), an increase in weight (OR 2.36, 95% CI 1.76-3.17), male gender (OR 1.27, 95% CI 1.11-1.47), and concomitant use of valproic acid (OR 1.97, 95% CI 1.61-2.40), selective serotonin reuptake inhibitors (OR 1.63, 95% CI 1.33-1.99) or buspirone (OR 2.24, 95% CI 1.33-3.77). CONCLUSION: Treatment with clozapine, olanzapine or risperidone appears to be associated with an increased risk of glucose intolerance.

Adverse Drug Reaction Reporting Systems↗

Antipsychotic-induced venous thromboembolism: a review of the evidence.

Psychiatric disorders themselves and treatment with conventional antipsychotic medications have in a number of early studies been associated with venous thromboembolism. In general, information on the relationship between antipsychotics and this possible adverse effect is in the form of case reports and open cross-sectional studies. However, recently the association between conventional antipsychotics and venous thrombosis has been strengthened as a result of the publication of a large, nested, case-control study. In this study, low-potency antipsychotic drugs were more strongly associated with venous thrombosis than high-potency drugs. In addition, recent epidemiological data support an association between the atypical antipsychotic agent clozapine and venous thromboembolism. The risk for venous thromboembolism seems to be highest during the initial months of treatment with antipsychotics. The biological mechanisms responsible for this possible adverse drug reaction are unknown, but a number of hypotheses have been suggested. The increased risk may be the result of drug-induced sedation, obesity, hyperleptinaemia, antiphospholipid antibodies and increased activity in the coagulation system. The association could also be related to underlying risk factors present in patients with psychosis such as smoking. Despite the limitations of present knowledge, clinicians should be aware of this possible adverse drug reaction and should consider interrupting or changing the antipsychotic regimen in patients in whom this reaction is suspected. More studies are needed in order to further elucidate this adverse effect, particularly to determine the incidence rate, possible predisposing factors and the biological mechanisms involved.

Antipsychotic Agents↗

Lamotrigine serum concentrations throughout the menstrual cycle--a study of 2 cases.

OBJECTIVES: To measure the serum concentrations of lamotrigine throughout a complete menstrual cycle. METHODS: Serum concentrations of lamotrigine, estradiol, and progestogen throughout a menstrual cycle were measured in 2 young women not using hormonal contraception. RESULTS AND CONCLUSIONS: The physiological hormonal fluctuations during an ovulatory cycle were not associated with clinically relevant changes in lamotrigine serum concentrations.

Adult↗