Preventable ADRs leading to hospitalization - results of a long-term prospective safety study with 6,427 ADR cases focusing on elderly patients.

BACKGROUND: Studies evaluating the impact of age and potentially inappropriate medication (PIM) on avoidable adverse drug reactions (ADRs) are scarce. METHODS: In this prospective, multi-center, long-term (8.5 years) observational study, we analysed ADRs leading to hospitalization in departments of internal medicine. ADRs causality and preventability were assessed using standardised algorithms. PIM was defined based on the PRISCUS-list. Multivariate analyses and estimation of ADR incidence rates were conducted. RESULTS: Of all 6,427 ADR patients, a preventable ADR was present in 1,253 (19.5%) patients (elderly patients ≥70 years: 828). Risk factors for preventable ADRs in elderly patients were multimorbidity, two to four ADR-causative drugs, and intake of particular compounds (e.g. spironolactone) but not sex, PIM usage, or the total number of drugs. Regarding particular compounds associated with preventable ADRs, highest incidence rates for preventable ADRs were found for patients aged ≥70 years for spironolactone (3.3 per 1,000 exposed persons (95% CI: 1.4-6.6)) and intermediate-acting insulin (3.3 per 1,000 exposed persons (95% CI: 1.6-6.1)). CONCLUSION: Avoiding PIM usage seems to be of limited value in increasing safety in elderly patients whereas our results underline the importance of an individualized medication review of the most commonly implicated drugs in preventable ADRs (supported by BfArM FoNr: V-11337/68605/2008-2010).

Chronomodulated chemotherapy with oxaliplatin, 5-FU and sodium folinate in metastatic gastrointestinal cancer patients: original analysis of non-hematological toxicity and patient characteristics in a pilot investigation.

OBJECTIVE: Several clinical trials have demonstrated that oxaliplatin is a useful agent in combination with 5-fluorouracil (5-FU) and folinic acid (FA) for the treatment of patients with colorectal carcinoma. The aims of this pilot study were to evaluate non-hematological toxicity and patient characteristics in gastrointestinal cancer patients treated with chronomodulated chemotherapy consisting of oxaliplatin, 5-FU and sodium folinate. METHODS: Patients with metastatic gastrointestinal cancer received a chronomodulated regimen with oxaliplatin (25 mg/m2), 5-FU (750 mg/m2) and sodium folinate (150 mg/m2). Non-hematological toxicities were evaluated and analyzed in relation to patient characteristics, i.e. age, sex, body weight, body mass index (BMI), body surface area and smoking status. Toxicity was graded according to the National Cancer Institute Common Toxicity Criteria. RESULTS: The severity of non-hematological toxicity was generally moderate. Grade 4 toxicity was only found in 2 patients with diarrhea (12.5%). The most frequent common adverse events were nausea, Grades 1 - 2 in 13 patients (81.3%), followed by motor neuropathy, Grades 1 - 3 in 11 patients (68.9%). The analyses showed that patient characteristics such as BMI and smoking status were associated with mucositis/stomatitis, vomiting or mood alteration. Furthermore, there was a relationship between smoking status and the overall non-hematological toxicity. Smokers had significantly higher overall toxicity than non-smokers and body mass index correlated significant with overall toxicity. CONCLUSION: The results of this pilot investigation suggest that a chronomodulated regimen with oxaliplatin, 5-FU and sodium folinate has a manageable non-hematological toxicity profile and that toxicity of the chronomodulated schedule studied depends on the patient characteristics. In further investigations, risk factors determining chemotherapeutic toxicity should be considered. Because of the small number of patients in this pilot investigation, the findings need to be confirmed in a larger clinical study.

Pharmacokinetics of oxaliplatin and non-hematological toxicity in metastatic gastrointestinal cancer patients treated with chronomodulated oxaliplatin, 5-FU and sodium folinate in a pilot investigation.

OBJECTIVE: To analyze in a pilot study the association between the pharmacokinetics of chronomodulated administered oxaliplatin and non-hematological toxicity in patients with metastatic gastrointestinal cancer. METHODS: 16 patients received a 4-day chemotherapeutic regimen consisting of a 12-h chronomodulated infusion of oxaliplatin (25 mg/m2) followed by a 12-h chronomodulated infusion of 5-fluorouracil (750 mg/m2) and sodium folinate (150 mg/m2) daily. Plasma pharmacokinetics of oxaliplatin, measured as ultrafiltrable platinum, were determined. RESULTS: Pharmacokinetics and non-hematological adverse events could be assessed in all patients included in the study. Pharmacokinetic parameters showed moderate interpatient variability. The occurrence of nausea and vomiting, but not diarrhea, was significantly associated with the pharmacokinetics of ultrafiltrable platinum. Thus, increased AUC values were observed in patients who experienced nausea or vomiting. No differences in pharmacokinetic parameters were found between patients with and without oxaliplatin-induced neurotoxicity or the other selected non-hematological toxicities. CONCLUSION: The preliminary results in this pilot study suggest an association between pharmacokinetics of ultrafiltrable platinum and non-hematological toxicity such as nausea and vomiting. Furthermore, although the sample size is limited, systemic exposure to ultrafiltrable platinum appears to predict the risk of non-hematological toxicity in patients treated with chronomodulated oxaliplatin combined with 5-FU and FS.

Assessment of frequencies of lifestyle factors and polymorphisms of drug-metabolizing enzymes (NAT2, CYP2E1) in human hepatocellular carcinoma (HCC) patients in a department of surgical medicine--a pilot investigation.

The pathogenesis of human hepatocellular carcinoma (HCC) is a multistage process with the involvement of a multifactorial etiology. The role of drugs as risk factors has not been conclusively ascertained, but it appears that the use of oral contraceptives can be included. In the multifactorial etiology of human hepatocellular carcinoma (HCC), an association and interaction between genetic polymorphisms of xenobiotic metabolizing enzymes, lifestyle factors and cancer risk has been postulated. This pilot investigation examines the frequency of polymorphisms in selected genes (NAT2, CYP2E1) coding for xenobiotic metabolizing enzymes, and life-style habits (cigarette smoking, alcohol consumption) in 38 HCC patients. Genotyping of xenobiotic metabolizing enzymes was carried out using polymerase chain reaction--restriction fragment length polymorphism methods and DNA extracted from peripheral blood cells. In addition, HCC patients were interviewed with regard to their cigarette smoking habits and alcohol consumption using a standardized questionnaire. The results of this pilot investigation showed that the majority of the HCC patients smoke and consume alcohol. We found no predominance of slow acetylators (45%) or rapid acetylators (55%). 70.6% of slow acetylators were smokers. 86.5% of all patients with homozygote PstI/RsaI genotype also carried the homozygote DraI genotype, whereas 10.8% of all subjects with heterozygote PstI/RsaI genotype also carried the heterozygote DraI genotype. These genotype frequencies remain to be confirmed in a larger ethnic group. Whether polymorphisms of xenobiotic metabolizing enzymes is an important risk factor in (cigarette smoking-/alcohol consumption) HCC or not is currently being investigated in a case-control study in the same ethnic group.

Assessment of ADRs associated with lipid-lowering agents recorded in the Department of Internal Medicine, University Hospital, Jena.

Drug-related illness is an important cause of admission to hospital. Little information is available regarding the frequency of ADRs caused by antilipidemic agents classified as HMG-CoA reductase inhibitors (statins). Treatment with statins has been associated with the occurrence of myopathy or liver toxicity in case reports. Recent lipid intervention studies have involved the implementation of lipid lowering therapy with HMG-CoA reductase inhibitors in cardiovascular risk management. Since January 1997 we have been involved in a study, the aim of which was to improve the spontaneous drug information reporting system in Germany. The study was supported by the German Federal Institute for Drugs and Medical Devices, the "Bundesinstitut für Arzneimittel und Medizinprodukte", Berlin BfArM. Between early 1997 and late 2000, as a result of this monitoring of ADRs, we analyzed all patient histories concerning therapy with statins. A total of 550 ADR patients were evaluated, (209 male, 341 female) with a mean age of 66.4 years. 27 (4.9%) of all patients had received statins (atorvastatin = 12, fluvastatin = 7, simvastatin as well as pravastatin = 3, lovastatin = 2). Only 2 of the 27 patients admitted to hospital for typical ADRs of statins such as skeletal muscle toxicity (e.g. myalgia, rhabdomyolysis) or disorders involving hepatic structure or function were receiving statins (atorvastatin). An increased risk of rhabdomyolysis has been reported in the case of several statins, following concomitant use with erythromycin, cyclosporine or itraconazole, all of which are potent inhibitors of CYP3A4 enzyme. But only 1 atorvastatin patient had received cyclosporine as a CYP3A4 inhibitor. After discontinuing medication, signs of intoxication disappeared. The antihyperlipidemic drugs available are generally safe and effective, and rate of ADRs is low if concomitant intake of other drugs and the differing pharmacokinetic profiles of the statins are considered.

Dipyrone and diclofenac do not influence creatinine-clearance, inulin-clearance or PAH-clearance in healthy male volunteers.

The effects of the non-steroidal anti-inflammatory drug diclofenac and the pyrazolone derivative dipyrone on renal function were compared with those of placebo in 12 healthy male volunteers in a randomized, controlled, triple-crossover study with a wash-out period of 4 days between each of the 3 trial periods (dipyrone, diclofenac and placebo) which lasted three days each. The volunteers received dipyrone (1 g, 3 times/day for 2 days, followed by twice 1 g on the main trial day, which was day 3 of each study period) or diclofenac (50 mg, 3 times/day for 2 days, followed by twice 50 mg on the main trial day) or placebo orally. Standardized meals (50 mEq sodium per day) were given from one week before the start until the end of the study and on the main trial days a protein-rich lunch (2 g protein/kg body weight) was taken. Renal function was assessed in each study period by measurement of creatinine-clearance, inulin-clearance and p-aminohippurate (PAH)-clearance to characterize glomerular filtration rate and renal plasma flow. High protein intake induced glomerular hyperfiltration (increased creatinine-clearance, inulin-clearance and PAH-clearance) in all 3 study periods (dipyrone, diclofenac, placebo). Dipyrone and diclofenac had no effect on renal clearance of creatinine, inulin or PAH in comparison to placebo. These results show that dipyrone and diclofenac at therapeutic dosages over 3 days do not decrease glomerular filtration and renal plasma flow in healthy individuals. Furthermore, it is unlikely that prostaglandins play a major role in protein-induced glomerular hyperfiltration.

Analysis of point mutation in exon 2 of CYP2E1 gene in renal cell/urothelial cancer patients in comparison with control population.

OBJECTIVE: Genetic polymorphisms of human cytochrome P450s have been implicated to be of importance for susceptibility to different cancers. Recently, a point mutation was found in the exon 2 of the CYP2E1 gene (CYP2E1*2) [Hu et al. 1997]. In order to evaluate a possible link between the point mutation in exon 2 of the CYP2E1 gene and the susceptibility to renal cell/urothelial cancer, we developed a screening method based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). MATERIAL: DNA of peripheral white blood cells was isolated from 158 renal cell/urothelial cancer patients as well as from 150 controls. METHOD: Primers for PCR were designed by the Primer 3 release 0.1 program. The PCR yield a product of 215 base pairs (bp), which was digested with the restriction enzyme Hha I. The DNA fragments were separated on a 3% agarose gel stained with ethidium bromide. Restriction enzyme digestion of the PCR product obtained from the wild-type DNA resulted in the appearance of a 66 bp, a 43 bp, a 40 bp, a 39 bp and a 28 bp DNA fragment. In contrast to the wild-type, the digestion of the PCR product from DNA carrying the point mutation resulted in the loss of the 39 bp and 40 bp fragments and the appearance of an additional 79 bp fragment. Therefore, the loss of one Hha I restriction site caused by a single nucleotide exchange is suitable for the identification of the point mutation in exon 2 of CYP2E1 gene. RESULTS: However, we could not detect any point mutation in any of the 158 renal cell/urothelial cancer patients or the 150 controls. The distribution of the point mutation in exon 2 of CYP2E1 gene did not show any difference in renal cell/urothelial cancer patients and controls. CONCLUSION: This might indicate a lack of association between this CYP2E polymorphism (CYP2E1*2) and renal cell/urothelial cancer.

Bioavailability study with 2 different levonorgestrel-containing drugs in women.

In a randomized, single dose, open crossover study in 24 healthy women, aged between 20 and 28 years, the relative bioavailability of the test product Mini 30 (0.03 mg levonorgestrel) in comparison to a reference, Microval, was investigated after single dose administration. Because there was a difference in the in vitro dissolution test, it was of interest whether this difference had an influence on the extent and rate of absorption. Whereas 99.4% of the test were dissolved after 20 minutes, only 48.3% of the reference were dissolved after 45 minutes, 74.8% after 120 minutes and 95.5% after 240 minutes. Blood samples were taken from time 0-72 hours after administration. All serum samples were analyzed twice in a radioimmunoassay which was validated before the start of the study. The limit of quantitation was at 50 pg/ml. The AUC0 -infinity ratio test/reference and the 90% confidence interval were 104.8%, and 99.10%, respectively. The Cmax ratio test/reference and the 90% confidence interval were 175.5%, and 159.8%-192.8%, respectively. With regard to the extent of absorption (AUC0-infinity) the 2 preparations were within the acceptance range for bioequivalence whereas they were outside the acceptance range for the rate of absorption (Cmax). The elimination half-lives of LNG did not differ between the test and reference preparations (25.08 +/- 11.94 h, and 25.70 +/- 10.08 h, respectively). So, the in vitro results concerning the rate of dissolution were confirmed by the in vivo findings in Cmax whereas regarding the extent of absorption (AUC) there were no differences between the 2 preparations.

CYP2E1 genotyping in renal cell/urothelial cancer patients in comparison with control populations.

OBJECTIVE: Genetic polymorphisms in enzymes involved in carcinogen metabolism have been found to influence susceptibility to cancer. Ethanol-inducible CYP2E1 is an enzyme of major toxicological interest because it metabolizes several drugs, precarcinogens, and solvents to reactive metabolites. In the present investigation, we studied the cytochrome P450 2E1 genetic polymorphism in renal cell/urothelial cancer patients in comparison with healthy control populations in the regions of Jena and Halle in Germany. PATIENTS AND MATERIAL: DNA of peripheral white blood cells was isolated both from 273 renal cell/urothelial cancer patients and 298 controls from the regions of Jena and Halle. METHOD: We focused on polymorphisms in the promoter region and intron 6 of the CYP2E1 gene. The polymorphims were identified as restriction fragment length polymorphisms (RFLPs) by polymerase chain reaction (PCR) and subsequently applying the restriction enzymes PstI/RsaI and DraI. RESULTS: In the region of Jena as well as of Halle, the frequency distributions of the PstI/RsaI, DraI, and combined DraI + PstI/RsaI genotypes showed no significant differences between controls and renal cell/urothelial cancer patients. We did not find significant differences between Jena and Halle. 86.7% of all subjects with a homozygote PstI/RsaI genotype also carried a homozygote DraI genotype, whereas 5.2% of all subjects with a heterozygote PstI/RsaI genotype also carried a heterozygote DraI genotype. The heterozygote genotype of PstI/RsaI polymorphism always determines the heterozygote genotype of DraI polymorphism. Our results failed to demonstrate any differences in the distribution of CYP2E1 polymorphisms between renal cell/urothelial cancer patients and controls. CONCLUSION: Summing up, our results show that CYP2E1 genotype cannot predict risk for renal cell/urothelial cancer in the population from 2 different regions in Germany. The results demonstrate a lack of association between CYP2E1 genetic polymorphism and renal cell cancer/urothelial cancer.

Impact of CYP2E1 genotype in renal cell and urothelial cancer patients.

Genetic polymorphisms of enzymes involved in carcinogen metabolism have been found to influence susceptibility to cancer. Ethanol-inducible CYP2E1 is an enzyme of major toxicological interest because it metabolizes several drugs, precarcinogens and solvents to reactive metabolites. In the present study, we investigated the cytochrome P450 2E1 genetic polymorphism in renal cell/urothelial cancer patients from two German regions, Jena and Halle, different with respect to their environmental pollution degree in comparison with healthy controls from the same regions. DNA of peripheral white blood cells was isolated both from 224 renal cell/urothelial cancer patients and 304 controls. We focussed on polymorphisms in the promoter region and intron 6 of the CYP2E1 gene. The polymorphisms were identified as RFLP's by amplification of the appropriate DNA fragment and subsequent digestion with the restriction enzymes PstI, RsaI and DraI. In Jena as well as in Halle, the frequency distributions of the PstI/RsaI, DraI and combined DraI + PstI/RsaI genotypes showed no significant differences between controls and renal cell/urothelial cancer patients. We did not find significant differences between Jena and Halle. 86.2% of all subjects with a homozygote PstI/RsaI genotype also carried a heterozygote DraI genotype, whereas 5.1% of the subjects with a heterozygote PstI/RsaI genotype also carried a heterozygote DraI genotype. Renal cell cancer as well as urothelial cancer risk was not elevated in patients with heterozygote DraI, PstI/RsaI and combined DraI + PstI/RsaI genotypes (odds ratios slightly insignificantly increased). Interestingly enough, an association between these polymorphisms and renal cell cancer risk was found in the female subgroup but not in the male subgroup. The basis of these sex-specifically increased risks are different frequencies concerning heterozygote and homozygote genotypes in controls and cancer patients. In controls, the heterozygote genotype frequency was lower in females than in males. In renal cell cancer patients, the results were quite the contrary. Summing up, our results demonstrate an lack between CYP2E1 genetic polymorphism and renal cell/urothelial cancer risk.

[The pharmacokinetics of a new anti-arrhythmic substance, Z-2-amino-5-chlorobenzophenoneamidinohydrazone (AWD-G256)]. / Untersuchungen zur Pharmakokinetik der neuen antiarrhythmischen Substanz Z-2-Amino-5-chlorbenzophenonamidinohydrazonacetat (AWD-G256).

In 4 studies blood levels and metabolites of Z-2-amino-5-chlorobenzophenoneamidinohydrazoneacetate (AWD-G256) after different dosages and forms of application on patients and healthy volunteers were investigated. In addition the pharmacokinetic parameters were calculated. The determination of pharmacokinetic parameters was possible only after i.v. application of dosages higher than 0.30 mg.kg-1 b.m. as well as p.o. administration of dosages higher than 100 mg. The blood level curve after i.v. application demonstrated a 2-compartment model and after p.o. application a 1-compartment model. Exact pharmacokinetic data can't be clear estimated with this studies.

[Hemodynamic effects and adverse effects of the anti-arrhythmic substance AWD-G256 in man]. / Hämodynamische Effekte und Verträglichkeit der antiarrhythmischen Substanz AWD-G256 beim Menschen.

In 19 patients with different supraventricular tachycardias the antiarrhythmic drug AWD-G256 was studied to investigate the effects on hemodynamic parameters. Over all, stroke volume, pulmonary pressure and systemic blood pressure were not significantly altered. The only main adverse effect was a transient rise of serum transaminases in two patients. We conclude that AWD-G256 is usually hemodynamically tolerated, but the antiarrhythmically effective dosage is not reached yet.

A common variant of the angiotensinogen gene and the risk of coronary artery disease in a German population.

The thymidine to cytosine transition at position 704 in exon 2 of the angiotensinogen gene leads to the amino acid substitution of threonine for methionine (T235 variant) and is responsible for elevated plasma levels of angiotensinogen. To examine the influence of T235 on the risk of coronary artery disease (CAD) we genotyped 184 CAD patients, 77 controls in whom CAD was excluded angiographically, and 155 healthy controls without signs of CAD by polymerase chain amplification and restriction enzyme digestion. Allele frequencies for A (wildtype) and a (mutant allele) in the total study population were 0.538 and 0.462, 0.536 and 0.464 in the healthy controls, and 0.481 and 0.519 in patients with excluded CAD, respectively. The allele frequencies and the genotype distribution in these groups did not show a significant difference. In conclusion, we did not observe an association between the T235 variant of the angiotensinogen gene and the risk of CAD.

[Clinical-electrophysiologic studies on the actions of the anti-arrhythmic substance AWD-G256 in man]. / Klinisch-elektrophysiologische Untersuchungzen zur Wirkung der antiarrhythmischen Substanz AWD-G256 beim Menschen.

The effects of the new antiarrhythmic drug AWD-G256 (1) were investigated by clinical electrophysiology (His bundle electrography, programmed electrical stimulation) in 19 patients with supraventricular tachycardias but without structural heart disease. In a maximal dosage of 0.45 mg/kg body mass 1 only minimally affects electrophysiological parameters of the impulse formation and conduction. At this time the therapeutic value of 1 is not clear.

Evaluation of an oral pulsatile delivery system for melatonin in humans.

Using melatonin (MT) as a circadian synchroniser in humans to treat a variety of rhythm disorders, it is desirable to develop controlled-release dosage forms that deliver MT in accordance with its endogenous secretory pattern as well as preparations that release MT in a pulsatile way. In this paper we describe two oral pulsatile dosage forms containing 10 mg MT each (capsules B and C) and a fast-release form containing 5 mg MT (capsule A) studied in a randomised single-dose, threefold cross-over study in 15 healthy male volunteers. The concentrations of both MT in serum and its main metabolite 6-sulfatoxymelatonin (aMT6s) in urine were analysed by means of specific radioimmunoassays up to 10 h p.a. of the MT preparations. Mean peak concentrations of MT in serum were reached between 0.5 h and 0.75 h (Cmax[1] pmol/ml): 20.7 (A), 16.4 (B), 9.7 (C). The capsules B and C released a second MT pulse after about 3.5 h with Cmax[2] of 13.0 and 17.5 pmol/ml, respectively. Dose proportionality for the MT preparations studied was calculated by determining the AUC0-infinity (pmol/ml.h): 18.4 (A), 36.1 (B), 42.4 (C). The terminal serum half-lives of MT ranged between 0.64 and 0.84 h. The time course of the renally excreted aMT6s correlated with that of changes in MT serum concentrations.

[Fluoroquinolones: utilization in renal and urogenital tract infections]. / Fluorchinolone: Einsatz bei Infektionen der Nieren und des Urogenitaltrakts.

The purpose of this review is to give an introduction in the class of fluoroquinolones, which has become a large class of substances, and to discuss the use, role, and place of these drugs in the treatment of urinary tract infections. The classification of the fluoroquinolones contains four groups. Antibacterial spectrum, pharmacokinetics, and indications are the main criteria. The various fluoroquinolones differ in their antibacterial spectrum, the antibacterial activity, and pharmacokinetic properties. Therefore selection, use, and dosage regime of the substances should be carried out under respective clinical requirements and medical points of view. The physician has to consider the specific indications for each substance in each individual case. Fluoroquinolones are suitable antibacterial agents for various urinary tract infections and are a valuable and useful addition to the antimicrobial treatment.

A melatonin preparation with a pulsatile liberation pattern: a new form of melatonin in replacement therapy.

Using melatonin (MLT) as a circadian synchroniser in humans to treat rhythm disorders, it is desirable to have controlled-release dosage forms. Following in vitro liberation tests, one fast-release form containing 5 mg MLT (capsule A) and two oral pulsatile-dosage forms containing 10 mg MLT each (capsules B and C) were studied in a randomised, single-dose, threefold cross-over study in 15 healthy male volunteers after investigation of capsule B in dogs. Mean peak concentrations of MLT in serum (pmol/ml) were reached between 0.5 h and 0.75 h: Cmax1 20.7 (A), 16.4 (B), 9.7 (C). Capsules B and C released a second MLT pulse after about 3.5 h with Cmax2 of 13.0 and 17.5 pmol/ml, respectively. The time course of the renally excreted main metabolite 6-sulphatoxymelatonin (aMT6s) correlates with that of changes in MLT serum concentrations. The kinetic profile of the delivery system is adjusted to the pattern of sleep maintenance disturbances.

[Oncologic pharmacotherapy of elderly patients]. / Onkologische Pharmakotherapie alter Patienten.

Age is the major risk factor for the development of cancer. Difficulties in medical treatment of elderly patients with cancer may be due to age dependent changes in physiological organ function, which result in pharmacokinetical and pharmacodynamical changes. They also may be due to co-morbidities with the need of pharmacological therapy. The choice of adequate treatment protocols has to consider this age dependent changes in pharmacokinetics and the presence of co-morbidities. Most of the data reporting results of medical oncological treatment in patients with cancer are collected in younger patients. Therefore, the present knowledge concerning medical oncological treatment of elderly patients with cancer is still limited.

Investigations into a new antiarrhythmic substance Z-2-amino-5-chlor-benzophenon-amidin-hydralazin in humans.

Z-2-amino-5-chlor-benzophenon-amidin-hydralazin is a new chemical potential antiarrhythmic substance. The blood levels were investigated after different dosages and forms of administration in patients and volunteers. The determination of the substance can be performed by high-pressure liquid chromatography. In addition the pharmacokinetic parameters were calculated. The pharmacokinetic profile is similar in humans and animals.

Absence of association between a common mutation in the methylenetetrahydrofolate reductase gene and the risk of coronary artery disease.

BACKGROUND: Elevated total plasma homocysteine levels are associated with an increased risk of coronary artery disease. Plasma homocysteine levels are influenced by nutritional and hereditary factors. A point mutation (cytosin to thymidine substitution; C677-->T) in the gene encoding methylenetetrahydrofolate reductase (MTHFR), has been reported to render the enzyme thermolabile and has been associated with elevations in homocysteine levels in homozygous carriers (TT genotype). METHODS: To examine the hypothesis that the T allele (coding for the thermolabile defect of MTHFR) influences the risk of coronary artery disease, we genotyped 340 patients with coronary artery disease and 105 control subjects in whom coronary artery disease was excluded by coronary angiography. Furthermore, we studied the genotype frequency in 104 age- and sex-matched healthy persons as a control group without signs of atherosclerotic disease. RESULTS: Allele frequencies for C (wild-type allele) and T allele (mutant allele) were 0.68 and 0.32 respectively in the healthy control subjects, 0.66 and 0.34 respectively in patients with angiographically excluded coronary artery disease and 0.69 and 0.31 respectively in coronary artery disease patients (P = NS). The allele frequencies of the total study population were 0.68 and 0.32. CONCLUSION: Our data show that homozygosity for the C677-->T mutation in this European population is not associated with increased risk of coronary artery disease. This finding suggests that the C677-->T mutation of the MTHFR gene does not represent a marker for increased cardiovascular risk.