Congenital adrenal hyperplasia in patients with adrenal tumors: a population-based case-control study.

PURPOSE: Congenital adrenal hyperplasia (CAH) has been associated with adrenal tumors (ATs) but the relationship is still unclear. The aim was to investigate if CAH was more common in patients with adrenal tumors and their characteristics. METHODS: Using national registers all patients with an AT diagnosis (cases) and selected matched controls without AT diagnosis were included from 1st January 2005 to 31st December 2019. The patients with a CAH diagnosis were scrutinized in detail. RESULTS: ATs were diagnosed in 26,573 individuals and in none of 144,124 controls. In 20 patients with ATs and 1 control, a CAH diagnosis was present. The odds for having CAH in patients with ATs was 109 (95% CI 15-809; P < 0.0001). Among cases, 5 had a CAH diagnosis before the discovery of ATs and 15 afterwards. Half were females and two had been screened for CAH neonatally. The mean age when the ATs was discovered was 55.6 years. Adrenalectomy was performed in seven patients. Five patients had unilateral adrenalectomy before the CAH diagnosis and did not have any glucocorticoid protection. After the CAH diagnosis, 15 were initiated on glucocorticoids and 6 on mineralocorticoids. The majority diagnosed with CAH before index date had classic CAH. In individual diagnosed after index date, only three had classic CAH. The rest had nonclassical CAH. During the follow-up time of 9 years, six deceased, two of them in an adrenal crisis. CONCLUSIONS: The prevalence of CAH was greater in patients with ATs than in patients without. In all patients with ATs, CAH should be considered.

Impact of the drug-drug interaction database SFINX on prevalence of potentially serious drug-drug interactions in primary health care.

PURPOSE: To investigate the impact of the integration of the drug-drug interaction database SFINX into primary health care records on the prevalence of potentially serious drug-drug interactions. METHODS: The study was a controlled before-and-after study on the prevalence of potential drug-drug interactions before and after the implementation of SFINX at 15 primary healthcare centres compared with 5 centres not receiving the intervention. Data on dispensed prescriptions from health care centres were retrieved from the Swedish prescribed drug register and analysed for September-December 2006 (pre-intervention) and September-December 2007 (post-intervention). All drugs dispensed during each 4 month period were regarded as potentially interacting. RESULTS: Use of SFINX was associated with a 17% decrease, to 1.81 × 10(-3) from 2.15 × 10(-3) interactions per prescribed drug-drug pair, in the prevalence of potentially serious drug-drug interactions (p = 0.042), whereas no significant effect was observed in the control group. The change in prevalence of potentially serious drug-drug interactions did not differ significantly between the two study groups. The majority of drug-drug interactions identified were related to chelate formation. CONCLUSION: Prescriptions resulting in potentially serious drug-drug interactions were significantly reduced after integration of the drug-drug interaction database SFINX into electronic health records in primary care. Further studies are needed to demonstrate the effectiveness of drug-drug interaction warning systems.

The effect of amiodarone on warfarin anticoagulation: a register-based nationwide cohort study involving the Swedish population.

Essentials Data on the effect of introducing amiodarone in patients already using warfarin regime are scarce. Information on 754 patients was extracted from three nationwide registers in Sweden. With amiodaron, 37% of patients had an international normalized ratio (INR) over 3.0 To avoid bleeding, the initiation of amiodarone should be accompanied by closer INR monitoring. SUMMARY: Background Data indicate that the interaction between warfarin and amiodarone results in an increased warfarin effect. There are several large, well-performed studies using genetic and clinical factors such as co-medication to predict an adequate starting dose of warfarin. However, longitudinal data on the effect of introducing amiodarone in patients on an ongoing warfarin regime are more scarce. Objectives An investigation of how initiation of amiodarone affects the anticoagulant effect and dosing of warfarin, using data from three nationwide registries. Patients/Methods In a retrospective cohort study including 754 patients, warfarin doses were compared between two 4-week periods, before and 18-21 weeks after initiating co-treatment with amiodarone. In addition, warfarin doses and international normalized ratio (INR) values were calculated week-by-week after the initiation of amiodarone. Results The initiation of amiodarone increased the mean INR from 2.6 to 3.1. The proportion of patients with a supratherapeutic INR over 3.0 and 4.0 increased from 12% to 37% and 0.9% to 5.5%, respectively. The subsequent mean decrease in warfarin dose was 24.6% (95% confidence interval [CI], 23.5, 25.6). The frequency of INR monitoring within 1 and 2 weeks after initiation of amiodarone was 67% and 90%. Conclusions Although warfarin doses in most patients were within the therapeutic range, more than one in three patients initiating co-treatment with amiodarone were exposed to a supratherapeutic anticoagulative effect within 3 weeks. In order to further avoid severe unnecessary bleeding, the initiation of amiodarone should be accompanied by closer INR monitoring, anticipating an average dose reduction of 25%.

The effect of carbamazepine on warfarin anticoagulation: a register-based nationwide cohort study involving the Swedish population.

BACKGROUND: There are data indicating that the interaction between warfarin and carbamazepine results in decreased warfarin efficacy. However, the evidence on the magnitude of and interindividual differences in susceptibility to this interaction has remained scarce. OBJECTIVES: To investigate the effect of carbamazepine on warfarin anticoagulation and warfarin maintenance doses by the use of data from three nationwide registries. PATIENTS/METHODS: In a retrospective cohort study including 166 patients, warfarin doses were compared 2-4 weeks before and 10-13 weeks after initiation of cotreatment with carbamazepine. In addition, warfarin doses and International Normalized Ratio (INR) values were calculated week-by-week during cotreatment. Data on prescribed warfarin doses and INR measurements were obtained from two large Swedish warfarin registers. Data on carbamazepine use were retrieved from the Swedish Prescribed Drug Register. RESULTS: The average warfarin doses were 49% (95% confidence interval 43-56) higher during carbamazepine treatment. The INR decreased upon carbamazepine initiation, and subtherapeutic INR levels were observed in 79% of all patients during the fifth week of cotreatment. Warfarin maintenance dose increases exceeding 50% and 100% were observed in 59% and 17% of patients, respectively. CONCLUSIONS: Four of five warfarin-treated patients in whom cotreatment with carbamazepine was initiated experienced subtherapeutic anticoagulative effect within 3-5 weeks. The warfarin dose was subsequently increased by 49%, a change that differed widely between patients. In order to avoid thrombosis and ischemic stroke, carbamazepine initiation should be accompanied by close INR monitoring to better meet the anticipated increase in dose demand.

The impact of interacting drugs on dispensed doses of warfarin in the Swedish population: A novel use of population based drug registers.

To investigate the impact of interacting drugs on the dispensed doses of warfarin in the Swedish population. This was a retrospective, cross-sectional population based register study of patients being dispensed warfarin. Warfarin doses were estimated in different age groups, in men and women, and in patients using interacting drugs. The influence of interacting drugs on the dispensed warfarin dose was analyzed using multiple regression. All 143,729 patients dispensed warfarin were analyzed. The dispensed dose of warfarin was highest in patients 30-39 years old and decreased with age. Co-medication with carbamazepine, simvastatin, paracetamol, amiodarone, fluconazole, lactulose, or bezafibrate was associated with significant changes in dispensed warfarin doses, by +40%, -3.4%, -7.3%, -8.2%, -8.8%, -9.0%, and -9.7%, respectively. After adjustment for age and gender, sulfamethoxazole was also found to significantly alter the dispensed warfarin dose (-6.1%). We provide new support for the previous scarce evidence of interactions between warfarin and carbamazepine, bezafibrate, and lactulose. Initiation or discontinuation of bezafibrate or lactulose in a patient on warfarin should warrant close clinical monitoring. The marked increased warfarin requirement associated with carbamazepine use supports moving from a more conservative reactive towards a proactive strategy including preventive warfarin dose adjustments to avoid potential adverse effects.

A pharmacometric model describing the relationship between warfarin dose and INR response with respect to variations in CYP2C9, VKORC1, and age.

The objective of the study was to update a previous NONMEM model to describe the relationship between warfarin dose and international normalized ratio (INR) response, to decrease the dependence of the model on pharmacokinetic (PK) data, and to improve the characterization of rare genotype combinations. The effects of age and CYP2C9 genotype on S-warfarin clearance were estimated from high-quality PK data. Thereafter, a temporal dose-response (K-PD) model was developed from information on dose, INR, age, and CYP2C9 and VKORC1 genotype, with drug clearance as a covariate. Two transit compartment chains accounted for the delay between exposure and response. CYP2C9 genotype was identified as the single most important predictor of required dose, causing a difference of up to 4.2-fold in the maintenance dose. VKORC1 accounted for a difference of up to 2.1-fold in dose, and age reduced the dose requirement by ~6% per decade. This reformulated K-PD model decreases dependence on PK data and enables robust assessment of INR response and dose predictions, even in individuals with rare genotype combinations.

Integration of genetic, clinical, and INR data to refine warfarin dosing.

Well-characterized genes that affect warfarin metabolism (cytochrome P450 (CYP) 2C9) and sensitivity (vitamin K epoxide reductase complex 1 (VKORC1)) explain one-third of the variability in therapeutic dose before the international normalized ratio (INR) is measured. To determine genotypic relevance after INR becomes available, we derived clinical and pharmacogenetic refinement algorithms on the basis of INR values (on day 4 or 5 of therapy), clinical factors, and genotype. After adjusting for INR, CYP2C9 and VKORC1 genotypes remained significant predictors (P < 0.001) of warfarin dose. The clinical algorithm had an R(2) of 48% (median absolute error (MAE): 7.0 mg/week) and the pharmacogenetic algorithm had an R(2) of 63% (MAE: 5.5 mg/week) in the derivation set (N = 969). In independent validation sets, the R(2) was 26-43% with the clinical algorithm and 42-58% when genotype was added (P = 0.002). After several days of therapy, a pharmacogenetic algorithm estimates the therapeutic warfarin dose more accurately than one using clinical factors and INR response alone.

Effects of vacuum exposure on stress and spectral shift of high reflective coatings.

Coating stress and spectral shift are affected by changing from ambient to vacuum environments. This change can affect optical systems that are aligned in air and used in a vacuum or in a dry environment. Spectral shifts up to 3% and reflected wave-front changes up to 0.35 waves peak to valley are reported for conventional electron-beam deposition and ion-assisted deposition. Alternatively, ion-beam sputtered coatings have virtually no changes between different pressure environments.