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Biomedical subjects

Olav Spigset

Publications and source records attributed to Olav Spigset.

At least 19 recordsLinked to original sources
PubMed2007

Antipsychotic-induced extrapyramidal symptoms in patients with schizophrenia: associations with dopamine and serotonin receptor and transporter polymorphisms.

BACKGROUND: Little is known about the influence of polymorphisms of the dopamine and serotonin system on the risk for extrapyramidal symptoms (EPS) during treatment with antipsychotic drugs. METHODS: Of 119 subjects with schizophrenia treated with antipsychotics, 63 had current or previous EPS (acute dystonia, parkinsonism, tardive dyskinesia), and 56 had no such symptoms. All subjects were genotyped for a total of eight dopamine and serotonin receptor and transporter polymorphisms: the Taq1A polymorphism of the dopamine D(2) receptor (DRD2) gene, the Msc1 polymorphism of the dopamine D(3) receptor (DRD3) gene, the variable number of tandem repeat (VNTR) polymorphism of the dopamine transporter (DAT1) gene, four polymorphisms (102T/C, His452Tyr, 516 C/T, and Thr25Asn) of the serotonin 5-HT(2A) receptor (5HTR2A) gene, and the 5HTTLPR polymorphism of the serotonin transporter (5HTT) gene. RESULTS: The frequency of the A1 allele of the DRD2 Taq1A polymorphism was significantly higher in the EPS group than in the control group [16% vs. 7%, P = 0.040; odds ratio (OR) 2.4; 95% confidence interval (CI) 1.1-5.7]. Also, the 9 repeat allele of the DAT1 VNTR polymorphism was significantly more common in the EPS group (42% vs. 28%, P = 0.030; OR 1.9; 95% CI 1.1-3.3). Being a carrier of both DRD2 Taq1A A1 and DAT1 VNTR 9 repeat alleles was also significantly associated with the occurrence of EPS (19% vs. 6%, P = 0.040; OR 4.0; 95% CI 1.05-15.2) No significant differences in allele frequencies were found for the other polymorphisms. CONCLUSION: Presence of the Taq1A A1 allele of the DRD2 and the 9 repeat allele of the DAT1 VNTR polymorphisms might be risk factors for EPS caused by antipsychotic drugs.

Adult↗
PubMed2007

Spontaneously reported fatal suspected adverse drug reactions: a 10-year survey from Sweden.

PURPOSE: One of the main methods for monitoring the safety of marketed drugs is spontaneously reporting of suspected adverse drug reactions (ADRs). The objective of this study was to describe the pattern of spontaneously reported fatal adverse drug reactions (FADRs) by analysing data from the national spontaneous reporting system in Sweden. METHODS: In Sweden it is compulsory to report all new or serious suspected ADRs to the Medical Products Agency. The information in these reports is stored in the national database SWEDIS (Swedish Drug Information System). All suspected FADRs reported to SWEDIS between 1 January 1995 and 31 December 2004 were reviewed and analysed. RESULTS: During the study period 990 reports of FADRs were found. The main distribution of suspected FADRs was: haemorrhages (n = 603; 60.9%), blood and bone marrow dysfunction (n = 71; 7.2%), sudden death (n = 38; 3.8%) and pulmonary embolism (n = 30; 3.0%). Antithrombotic agents were the drugs most frequently implicated in the FADRs (n = 605; 61.1%). Vitamin K antagonists were reported in 453 cases (45.8%) and acetylsalicylic acid in 82 cases (8.3%). Among the fatalities with blood and bone marrow dysfunction methotrexate was the most frequently reported drug. For sudden death and pulmonary embolism, antipsychotics and oestrogen containing drugs, respectively, were most commonly reported. CONCLUSIONS: Bleeding complications amounted more than half of all reports of FADRs and vitamin K antagonists were implicated in most of these reports. However, as spontaneous reporting systems are primarily set up for signalling purposes, the data must be interpreted with utmost care.

Adolescent↗
PubMed2007

Cerebral haemorrhage induced by warfarin - the influence of drug-drug interactions.

PURPOSE: To evaluate the frequency, severity and preventability of warfarin-induced cerebral haemorrhages due to warfarin and warfarin-drug interactions in patients living in the county of Ostergötland, Sweden. METHODS: All patients with a diagnosed cerebral haemorrhage at three hospitals during the period 2000-2002 were identified. Medical records were studied retrospectively to evaluate whether warfarin and warfarin-drug interactions could have caused the cerebral haemorrhage. The proportion of possibly avoidable cases due to drug interactions was estimated. RESULTS: Among 593 patients with cerebral haemorrhage, 59 (10%) were assessed as related to warfarin treatment. This imply an incidence of 1.7/100,000 treatment years. Of the 59 cases, 26 (44%) had a fatal outcome, compared to 136 (25%) among the non-warfarin patients (p < 0.01). A warfarin-drug interaction could have contributed to the haemorrhage in 24 (41%) of the warfarin patients and in 7 of these (12%) the bleeding complication was considered being possible to avoid. CONCLUSIONS: Warfarin-induced cerebral haemorrhages are a major clinical problem with a high fatality rate. Almost half of the cases was related to a warfarin-drug interaction. A significant proportion of warfarin-related cerebral haemorrhages might have been prevented if greater caution had been taken when prescribing drugs known to interact with warfarin.

Adolescent↗
PubMed2006

[Customized drug therapy--how near is the goal?].

BACKGROUND: During the last years we have gained considerable knowledge , about genetic factors behind the huge inter-individual variation in drug response and the risk of adverse drug reactions. MATERIAL AND METHODS: The article is based upon a recent search in PubMed and the author's own studies and experience with genotyping related to drug therapy. RESULTS AND INTERPRETATION: A considerable genetic variability has been revealed both in the function of drug-metabolising enzymes, transport proteins participating in drug distribution and excretion, and drug targets. This variability may be important for the choice and dosage of a drug. A number of genotyping methods are available for routine pharmacogenetic testing today. In some cases, genotyping is helpful before start of drug therapy, while in other cases genotyping is not indicated before a clinical problem has arisen and needs treatment. Although there are some clear-cut examples of genotyping being important for customising drug treatment, the next decades will determine whether genotyping will make it possible to predict treatment response as a general principle before starting drug therapy.

Carrier Proteins↗
PubMed2006

[On-site testing for drug abuse in urine].

BACKGROUND: There is an increasing interest in on-site testing for drugs of abuse. METHODS: Based upon our own experience and published literature, we have reviewed advantages and disadvantages of such tests. On-site testing is also evaluated in relation to the recommendations for urinary testing of drugs of abuse from the Norwegian Health Authorities. RESULTS: The most significant advantage with on-site testing is provision of rapid results, usually within 5-10 minutes. Disadvantages are the risks of false positive and false negative results, the fact that numerous drugs cannot be tested for, and the limited possibilities to detect manipulation. According to Norwegian regulations, on-site testing can be used for medical purposes, but cannot be used as the only method if a positive result may cause sanctions such as e.g. exclusion from school, job dismissal or loss of parental rights. There are also special requirements for the organization of such testing. INTERPRETATION: Before starting on-site testing for drugs of abuse, it should be considered if such testing is allowed or discouraged in the specific case. It is mandatory to know how the specific test works and to have routines for follow-up of positive test results.

False Negative Reactions↗
PubMed2006

Toxicological analysis in rats subjected to heroin and morphine overdose.

In heroin overdose deaths the blood morphine concentration varies substantially. To explore possible pharmacokinetic explanations for variable sensitivity to opiate toxicity we studied mortality and drug concentrations in male Sprague-Dawley rats. Groups of rats were injected intravenously (i.v.) with heroin, 21.5 mg/kg, or morphine, 223 mg/kg, causing a 60-80% mortality among drug-naïve rats. Additional groups of rats were pre-treated with morphine for 14 days, with or without 1 week of subsequent abstinence. Brain, lung and blood samples were analyzed for 6-acetylmorphine, morphine, morphine-3-glucuronide and morphine-6-glucuronide. i.v. morphine administration to drug-naïve rats resulted in both rapid and delayed deaths. The brain morphine concentration conformed to an exponential elimination curve in all samples, ruling out accumulation of morphine as an explanation for delayed deaths. This study found no support for formation of toxic concentration of morphine-6-glucuronide. Spontaneous death among both heroin and morphine rats occurred at fairly uniform brain morphine concentrations. Morphine pre-treatment significantly reduced mortality upon i.v. morphine injection, but the protective effect was less evident upon i.v. heroin challenge. The morphine pre-treatment still afforded some protection after 1 week of abstinence among rats receiving i.v. morphine, whereas rats given i.v. heroin showed similar death rate as drug-naïve rats.

Animals↗
PubMed2006

[Written drug advertisements--are they reliable?].

BACKGROUND: Drug advertisements affect the practice and continuous education of physicians. We assessed whether drug advertisements in Norway were in accordance with national regulations in the field. METHODS: All drug advertisements received by three general practitioners during a period of three months were collected. One advertisement for each of the 50 pharmaceutical products most frequently advertised was reviewed, available references obtained, and the information evaluated in relation to Norwegian regulations. RESULTS: A total of 294 advertisements for 77 different products were reviewed. The 50 chosen advertisements contained 191 reference citations, of which 93% were retrieved. The originator of the advertisement in question provided 72% of the references we asked for. We identified 262 promotional claims for which the regulations require a reference citation. Of these, 135 (52%) did not comply with the regulations, including 15 (6%) that were false. CONCLUSION: Only half of the information presented in drug advertisements was correct and clinically relevant. Relatively few statements were false, but a considerable proportion of statements gave an excessively positive picture of the product; hence, in general, this kind of information has no value as a source of information.

Advertising↗
PubMed2006

[Generic drugs instead of brand drugs prescriptions--long overdue].

BACKGROUND: Generic substitution of drugs was introduced in Norway in 2001. This implies an obligation for pharmacies to substitute the prescribed drug with a generic equivalent. Instead of using the drug manufacturers' trade names, doctors can prescribe drugs by using the generic (non-proprietary) names. The present paper gives an overview over current practice in different countries and discusses advantages and drawbacks. MATERIALS AND METHODS: Literature on generic substitution and generic prescription was sought on PubMed. Regulatory authorities in Norway and other countries were approached for additional information. RESULTS: In the United Kingdom, generic prescription has been dominating for many years. In Sweden, a successful trial period with generic prescribing was recently reported. We have not identified any pharmacological arguments against generic prescription. INTERPRETATION: Available data suggest that generic prescribing of drugs should be encouraged. Generic prescribing is likely to improve patient safety by assuring that the prescribed drug is in fact what is dispensed.

Denmark↗
PubMed2006

Alopecia associated with treatment with selective serotonin reuptake inhibitors (SSRIs).

PURPOSE: To study the association between alopecia and selective serotonin reuptake inhibitors (SSRIs) by estimating reporting rates and by making association comparisons within databases of adverse drug reactions (ADRs). METHODS: All reports of alopecia with marketed SSRIs until the end of 2004 were identified in SWEDIS, the national Swedish database for spontaneously reported ADRs, and in Vigibase, the international ADR database of the World Health Organization. Total SSRI sales volumes in Sweden until the end of 2004 were obtained from the National Corporation of Swedish Pharmacies. The Bayes' Confidence Propagation Neural Network (BCPNN) method was used to estimate associations between alopecia and each of the SSRIs within the two databases. RESULTS: A total of 27 reports of alopecia were identified in SWEDIS. As two reports concerned the use of two SSRIs, there was a total of 29 drug-ADR combinations. All except three reports concerned women (88.9%). The reporting rate of alopecia in Sweden was significantly higher with sertraline compared with citalopram; 20.1 (95%CI 10.7-34.4) reports per million patient-years versus 4.5 (95%CI 1.8-9.3) reports per million patient-years. No significant differences in reporting rates were noted for the remaining SSRIs. Sertraline also showed a statistically significant association with alopecia in both SWEDIS and Vigibase. Citalopram was significantly associated with alopecia in Vigibase, but not in SWEDIS. No statistically significant associations were found for any of the other SSRIs. CONCLUSIONS: Alopecia appears to be a rare ADR to SSRIs. The risk of alopecia seems to vary between the different SSRIs, and might be higher in women than in men.

Adult↗
PubMed2006

Adverse drug reactions of antidepressants and antipsychotics: experience, knowledge and attitudes among Norwegian psychiatrists.

Efficient prevention of adverse drug reactions (ADRs) requires knowledge about their severity and pharmacological mechanisms and is dependent on reliable data on their frequencies and possible risk factors. The study was conducted to investigate the prescribers' experience and understanding of the ADRs of psychotropic drugs, and their attitude towards reporting these. In a questionnaire, physicians treating adult psychiatric patients were asked which ADRs that they regarded bothersome for some of the most widely used antidepressants and antipsychotics. Questions about the relationship between blockade of drug receptors and ADRs, and about the physicians' personal experience of and attitudes towards reporting of ADRs were also included. In total, 70 of 91 questionnaires (78%) were returned. The mean number of ADRs regarded bothersome ranged from 2.4 to 9.3 for the various drugs/drug classes. Qualified psychiatrists stated a significantly higher number of bothersome ADRs than did the residents. The percentage of physicians associating blockade of a receptor with a specific ADR varied from 76% (histamine receptor blockade and sedation) to 37% (alpha(1)-adrenergic blockade and tachycardia). Thirty-nine per cent of the physicians had never reported an ADR to the Norwegian Medicines Agency. The number of ADRs considered bothersome was relatively high. The pattern of these ADRs generally mirrored the typical ADR profiles of the drugs. The knowledge of the underlying mechanisms of ADRs was more or less incomplete. The reporting rate of ADRs to the national regulatory authorities was low.

Adult↗
PubMed2006

Risk factors for extrapyramidal symptoms during treatment with selective serotonin reuptake inhibitors, including cytochrome P-450 enzyme, and serotonin and dopamine transporter and receptor polymorphisms.

INTRODUCTION: Extrapyramidal symptoms (EPS) are rare adverse drug reactions to selective serotonin reuptake inhibitors (SSRIs). This study aimed to investigate the potential risk factors for EPS associated with SSRIs including polymorphisms of cytochrome P-450 isoenzymes, and serotonin and dopamine transporters and receptors. METHODS: All spontaneous adverse drug reaction reports received by the Swedish Medical Products Agency until December 1999 that were coded with EPS and judged to be at least possibly related to SSRI treatment were included in the study. Reporting physicians received a form for collection of relevant information including current and previous use of SSRIs and antipsychotics, alcohol or substance abuse, central nervous system damage, a history of epilepsy or EPS, and a family history of Parkinson disease. A blood sample was also requested for genotyping of selected cytochrome P-450, and serotonin and dopamine transporter and receptor mutations. RESULTS: A total of 64 cases of EPS were reported. Twenty-eight forms (46%) were returned, and 20 blood samples were obtained. Identified potential risk factors included age of 65 years or older and the presence of the A1 allele of the D2 dopamine receptor gene (DRD2) Taq1A polymorphism (relative risk, 2.4; 95% confidence interval, 1.2-4.5 vs literature controls). No relationship was apparent for sex, drug dose, or other genetic polymorphisms. At least 1 additional potential risk factor for EPS, such as a history of central nervous system damage, alcohol or substance abuse, epilepsy, Parkinson disease, previous or current exposure to antipsychotic drugs, concomitant treatment with other antidopaminergic or serotonergic agents, or a history of EPS, was found in 93% of the cases. CONCLUSION: The risk of EPS with SSRIs seems to increase with advanced age and with the presence of the A1 allele of DRD2 Taq1A polymorphism. Because of the small sample size of our study and the use of historical controls rather than patients who did not experience EPS during SSRIs treatment, the DRD2 finding is preliminary and needs to be replicated in other studies before firm conclusions can be drawn. At least 1 additional potential risk factor was found in almost all cases.

Adult↗
PubMed2006

Heart failure induced by non-cardiac drugs.

Although heart failure is predominantly caused by cardiovascular conditions such as hypertension, coronary heart disease and valvular heart disease, it can also be an adverse reaction induced by drug therapy. In addition, some drugs have the propensity to adversely affect haemodynamic mechanisms in patients with an already existing heart condition. In this article, non-cardiac drugs known to be associated with the development or worsening of heart failure are reviewed. Moreover, drugs that may adversely affect the heart as a pump without causing symptoms or signs of heart failure are also included. The drugs discussed include anticancer agents such as anthracyclines, mitoxantrone, cyclophosphamide, fluorouracil, capecitabine and trastuzumab; immunomodulating drugs such as interferon-alpha-2, interleukin-2, infliximab and etanercept; antidiabetic drugs such as rosiglitazone, pioglitazone and troglitazone; antimigraine drugs such as ergotamine and methysergide; appetite suppressants such as fenfulramine, dexfenfluramine and phentermine; tricyclic antidepressants; antipsychotic drugs such as clozapine; antiparkinsonian drugs such as pergolide and cabergoline; glucocorticoids; and antifungal drugs such as itraconazole and amphotericin B. NSAIDs, including selective cyclo-oxygenase (COX)-2 inhibitors, are included as a result of their ability to cause heart disease, particularly in patients with an already existing cardiorenal dysfunction. Two drug groups are of particular concern. Anthracyclines and their derivatives may cause cardiomyopathy in a disturbingly high number of exposed individuals, who may develop symptoms of insidious onset several years after drug therapy. The risk seems to encompass all exposed individuals, but data suggest that children are particularly vulnerable. Thus, a high degree of awareness towards this particular problem is warranted in cancer survivors subjected to anthracycline-based chemotherapy. A second group of problematic drugs are the NSAIDs, including the selective COX-2 inhibitors. These drugs may cause renal dysfunction and elevated blood pressure, which in turn may precipitate heart failure in vulnerable individuals. Although NSAID-related cardiotoxicity is relatively rare and most commonly seen in elderly individuals with concomitant disease, the widespread long-term use of these drugs in risk groups is potentially hazardous. Pending comprehensive safety analyses, the use of NSAIDs in high-risk patients should be discouraged. In addition, there is an urgent need to resolve the safety issues related to the use of COX-2 inhibitors. As numerous drugs from various drug classes may precipitate or worsen heart failure, a detailed history of drug exposure in patients with signs or symptoms of heart failure is mandatory.

Clinical Trials as Topic↗