Bone abnormalities of the knee: prevalence and significance at MR imaging

Focal abnormal signal intensity within the distal femoral condyles or proximal tibial plateaus is frequently seen on T1- or intermediate-weighted magnetic resonance (MR) images of the knee. To characterize the prevalence and significance of these findings better, a retrospective study of MR imaging of the knee, performed on the first 434 consecutive patients at a primarily outpatient community MR imaging center, was undertaken. A signal intensity loss demonstrated on images with a short echo time (20 or 25 msec) was divided into three types based on morphologic criteria. A type 1 finding was a diffuse, often reticulated signal intensity loss in the metaphyseal and epiphyseal regions of bone. A type 2 loss was associated with an interruption in the smooth, black cortical line. A type 3 finding was a profound signal intensity loss primarily restricted to the immediate subcortical region. Seventeen percent of all cases revealed a type 1 or 2 loss that may have been compatible with acute bone injuries. These bone lesions were frequently associated with tears of the anterior cruciate ligament and contralateral collateral ligament, but infrequently these lesions were detected with plain radiography and arthroscopy. When associated with a weight-bearing cortex, bone injuries detected with MR imaging may explain clinical symptoms of pain on weight bearing, and type 1 injuries may represent regions of bone at increased risk for the subsequent development of insufficiency fractures if the bone is not adequately protected during trabecular healing.

Physicochemical Properties, Biotransformation, and Transport Pathways of Established and Newly Approved Medications: A Systematic Review of the Top 200 Most Prescribed Drugs vs. the FDA-Approved Drugs Between 2005 and 2016

BACKGROUND

Enzyme-mediated biotransformation of pharmacological agents is a crucial step in xenobiotic detoxification and drug disposition. Herein, we investigated the metabolism and physicochemical properties of the top 200 most prescribed drugs (established) as well as drugs approved by the US Food and Drug Administration (FDA) between 2005 and 2016 (newly approved).

OBJECTIVE

Our objective was to capture the changing trends in the routes of administration, physicochemical properties, and prodrug medications, as well as the contributions of drug-metabolizing enzymes and transporters to drug clearance.

METHODS

The University of Washington Drug Interaction Database (DIDB^®) as well as other online resources (e.g., CenterWatch.com, Drugs.com, DrugBank.ca, and PubChem.ncbi.nlm.nih.gov) was used to collect and stratify the dataset required for exploring the above-mentioned trends.

RESULTS

Analyses revealed that ~ 90% of all drugs in the established and newly approved drug lists were administered systemically (oral or intravenous). Meanwhile, the portion of biologics (molecular weight > 1 kDa) was 15 times greater in the newly approved list than established drugs. Additionally, there was a 4.5-fold increase in the number of compounds with a high calculated partition coefficient (cLogP > 3) and a high total polar surface area (> 75 Å²) in the newly approved drug vs. the established category. Further, prodrugs in established or newly approved lists were found to be converted to active compounds via hydrolysis, demethylases, and kinases. The contribution of cytochrome P450 (CYP) 3A4, as the major biotransformation pathway, has increased from 40% in the established drug list to 64% in the newly approved drug list. Moreover, the role of CYP1A2, CYP2C19, and CYP2D6 were decreased as major metabolizing enzymes among the newly approved medications. Among non-CYP major metabolizers, the contribution of alcohol dehydrogenases/aldehyde dehydrogenases (ADH/ALDH) and sulfotransferases decreased in the newly approved drugs compared with the established list. Furthermore, the highest contribution among uptake and efflux transporters was found for Organic Anion Transporting Polypeptide 1B1 (OATP1B1) and P-glycoprotein (P-gp), respectively.

CONCLUSIONS

The higher portion of biologics in the newly approved drugs compared with the established list confirmed the growing demands for protein- and antibody-based therapies. Moreover, the larger number of hydrophilic drugs found in the newly approved list suggests that the probability of toxicity is likely to decrease. With regard to CYP-mediated major metabolism, CYP3A5 showed an increased involvement owing to the identification of unique probe substrates to differentiate CYP3As. Furthermore, the contribution of OATP1B1 and P-gp did not show a significant shift in the newly approved drugs as compared to the established list because of their broad substrate specificity.

Chest radiographic findings in patients with tuberculosis with recent or remote infection

To determine if chest radiographic findings differ in adult tuberculosis patients with recent and remote infection, we reviewed the chest radiographs of 103 patients with tuberculosis in Los Angeles and performed RFLP analyses of their Mycobacterium tuberculosis isolates. Patients whose isolates had identical or closely related RFLP patterns were considered a "cluster." Most patients in large clusters (more than seven patients) had tuberculosis from recent infection, whereas most unclustered patients had tuberculosis from remote infection. Mediastinal adenopathy or pleural effusions were classified as typical of recent infection, and upper lobe infiltrates, cavitation, or fibrosis were classified as characteristic of remote infection. Radiographic patterns were typical of remote infection in 62% of patients and were characteristic of recent infection in 23% of patients. The distribution of these radiographic patterns was similar in clustered and unclustered patients, both with or without human immunodeficiency virus (HIV) coinfection. However, mediastinal adenopathy and pleural effusions were significantly more common in HIV-infected patients. We conclude that: (1) chest radiographic findings in adults with tuberculosis of recent infection are similar to those in patients with remote infection; (2) the distinctive chest radiographic findings in HIV-infected patients with tuberculosis are not due to an increased frequency of recent infection.

Pharmacokinetics of metoprolol during pregnancy and lactation

The objective of this study was to evaluate the steady-state pharmacokinetics of metoprolol during pregnancy and lactation. Serial plasma, urine, and breast milk concentrations of metoprolol and its metabolite, α-hydroxymetoprolol, were measured over 1 dosing interval in women treated with metoprolol (25-750 mg/day) during early pregnancy (n = 4), mid-pregnancy (n = 14), and late pregnancy (n = 15), as well as postpartum (n = 9) with (n = 4) and without (n = 5) lactation. Subjects were genotyped for CYP2D6 loss-of-function allelic variants. Using paired analysis, mean metoprolol apparent oral clearance was significantly higher in mid-pregnancy (361 ± 223 L/h, n = 5, P < .05) and late pregnancy (568 ± 273 L/h, n = 8, P < .05) compared with ≥3 months postpartum (200 ± 131 and 192 ± 98 L/h, respectively). When the comparison was limited to extensive metabolizers (EMs), metoprolol apparent oral clearance was significantly higher during both mid- and late pregnancy (P < .05). Relative infant exposure to metoprolol through breast milk was <1.0% of maternal weight-adjusted dose (n = 3). Because of the large, pregnancy-induced changes in metoprolol pharmacokinetics, if inadequate clinical responses are encountered, clinicians who prescribe metoprolol during pregnancy should be prepared to make aggressive changes in dosage (dose and frequency) or consider using an alternate beta-blocker.

Gestational diabetes mellitus management with oral hypoglycemic agents

Oral hypoglycemic agents such as glyburide (second-generation sulfonylurea) and metformin (biguanide) are attractive alternatives to insulin due to lower cost, ease of administration, and better patient adherence. The majority of evidence from retrospective and prospective studies suggests comparable efficacy and safety of oral hypoglycemic agents such as glyburide and metformin as compared to insulin when used in the treatment of women with gestational diabetes mellitus (GDM). Glyburide and metformin have altered pharmacokinetics during pregnancy and both agents cross the placenta. In this article, we review the efficacy, safety, and dosage of oral hypoglycemic agents for the treatment of gestational diabetes mellitus. Additional research is needed to evaluate optimal dosage for glyburide and metformin during pregnancy. Comparative studies evaluating the effects of glyburide and metformin on long-term maternal and fetal outcomes are also needed.

Prednisone Pharmacokinetics During Pregnancy and Lactation

To evaluate the steady-state pharmacokinetics of prednisone and its metabolite prednisolone in pregnant and lactating female subjects, 19 subjects received prednisone (4-40 mg/day orally) in early (n = 3), mid (n = 9), and late (n = 13) pregnancy as well as postpartum with (n = 2) and without (n = 5) lactation. Serial blood and urine samples were collected over 1 dosing interval. Prednisone and its metabolite, prednisolone, steady-state noncompartmental pharmacokinetic parameters were estimated. During pregnancy, prednisone apparent oral clearance increased with dose (35.1 ± 11.4 L/h with 5 mg, 52.6 ± 5.2 L/h with 10 mg, and 64.3 ± 6.9 L/h with 20 mg, P = .001). Similarly, unbound prednisone apparent oral clearance increased with dose. In addition, prednisolone renal clearance increased with dose (0.3 ± 0.3 L/h with 5 mg, 0.5 ± 0.4 L/h with 10 mg, and 1.3 ± 1.1 L/h with 20 mg, P = .002). Higher prednisone (r = 0.57, P ≤ .05) and prednisolone (r = 0.75, P ≤ .05) concentrations led to a higher percentage of unbound drug. Breast-milk/plasma area under the concentration-time curve ratios were 0.5-0.6 for prednisone and 0.02-0.03 for prednisolone. Relative infant doses were 0.35% to 0.53% and 0.09% to 0.18%, for prednisone and prednisolone, respectively. Prednisone and prednisolone exhibit dose- and concentration-dependent pharmacokinetics during pregnancy, and infant exposure to these agents via breast milk is minimal.

Pharmacokinetics of doxorubicin in pregnant women

PURPOSE

Our objective was to evaluate the pharmacokinetics (PK) of doxorubicin during pregnancy compared to previously published data from non-pregnant subjects.

METHODS

During mid- to late-pregnancy, serial blood and urine samples were collected over 72 h from seven women treated with doxorubicin for malignancies. PK parameters were estimated using non-compartmental techniques. Pregnancy parameters were compared to those previously reported non-pregnant subjects.

RESULTS

During pregnancy, mean (±SD) doxorubicin PK parameters utilizing 72 h sampling were: clearance (CL), 412 ± 80 mL/min/m(2); steady-state volume of distribution (Vss), 1,132 ± 476 L/m(2); and terminal half-life (T1/2), 40.3 ± 8.9 h. The BSA-adjusted CL was significantly decreased (p < 0.01) and T1/2 was not different compared to non-pregnant women. Truncating our data to 48 h, PK parameters were: CL, 499 ± 116 ml/min/m(2); Vss, 843 ± 391 L/m(2); and T1/2, 24.8 ± 5.9 h. The BSA-adjusted CL in pregnancy compared to non-pregnant data was significantly decreased in 2 of 3 non-pregnant studies (p < 0.05, < 0.05, NS). Vss and T1/2 were not significantly different.

CONCLUSIONS

In pregnant subjects, we observed significantly lower doxorubicin CL in our 72 h and most of our 48 h sampling comparisons with previously reported non-pregnant subjects. However, the parameters were within the range previously reported in smaller studies. At this time, we cannot recommend alternate dosage strategies for pregnant women. Further research is needed to understand the mechanism of doxorubicin pharmacokinetic changes during pregnancy and optimize care for pregnant women.

Atezolizumab for the First-Line Treatment of Non-small Cell Lung Cancer (NSCLC): Current Status and Future Prospects

Purpose: Atezolizumab is a programmed death ligand 1 (PDL-1) blocking antibody that was approved for metastatic non-small cell lung cancer (NSCLC) in patients with disease progression. Various studies have been initiated to explore the effectiveness of atezolizumab among different patient cohorts and disease statuses, including as first-line therapy. The purpose of this paper is to identify and summarize the trials that use atezolizumab as a first-line agent in chemotherapy-naïve patients with NSCLC. Methods: A database search was performed on Pubmed, Embase, and Wiley Cochrane Library-Central Register of Controlled Trials to identify clinical trials using atezolizumab as first-line therapy in NSCLC. Additionally, ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) were searched to identify relevant clinical trials. Conference abstracts from the American Society of Clinical Oncology, the European Society for Medical Oncology, and the American Association for Cancer Research were hand-searched. Any trial in which atezolizumab was used as first-line therapy in chemotherapy-naive patients with NSCLC was included. Results: Fifteen studies were ultimately included, all of which are current and ongoing. Of the 15 studies, 5 have reported results. When given in the first-line setting, atezolizumab had higher rates of objective response, progression-free survival, and overall survival, compared to the second and third-line settings. Among the 15 studies, atezolizumab is used as monotherapy (n = 5), in combination with chemotherapy (n = 6), in combination with targeted therapy such as bevacizumab (n = 1), as neoadjuvant/adjuvant therapy (n = 3), in combination with stereotactic body radiation therapy (n = 1), and in combination with or following chemoradiation (n = 1). Conclusion: Available evidence shows promising safety and efficacy with the use of atezolizumab as first-line therapy in NSCLC. Atezolizumab is currently being studied in a variety of treatment settings. If clinical benefits are shown, atezolizumab may deem to be a useful first-line agent in NSCLC.

DOACs in Mechanical and Bioprosthetic Heart Valves: A Narrative Review of Emerging Data and Future Directions

In the recent years, there has been significant transformation in the management of valvular heart disease (VHD), as a result of new minimally invasive technologies, such as the transcatheter aortic valve implantation (TAVI). Conventionally, mechanical heart valves require anticoagulation with warfarin to prevent thrombogenic events. Lately, there has been an uptrend in the usage of direct-acting oral anticoagulants (DOACs) in both mechanical and bioprosthetic heart valves. In clinical practice, there has shown to be notable heterogeneity in the antithrombotic regimen for patients. Recommendations from clinical guidelines and emerging data on DOAC use in these settings will be critically reviewed here. Future large, randomized-controlled trials are warranted to delineate the role of DOACs in patients receiving a bioprosthetic valve/TAVI or mechanical heart valve, with and without a baseline indication for anticoagulation or antiplatelets. Until clinical trial data from well-designed studies are available, providers must remain vigilant about DOAC use in patients with VHD, especially in patients with a bioprosthetic or mechanical heart valve.

Percutaneous mesenteric venous thrombectomy and thrombolysis: successful treatment followed by liver transplantation

Mesenteric vein thrombosis (MVT) is a rare cause of intestinal ischemia. Because of its nonspecific symptoms, diagnosis is often delayed. We describe a patient with liver cirrhosis who developed acute MVT while waiting for liver transplantation. Surgical intervention carried a high risk because of her underlying cirrhosis. Mesenteric venous thrombectomy and thrombolysis were performed with an AngioJet (Possis Medical, Minneapolis, MN) thrombectomy device and streptokinase infusion through transjugular route. The patient subsequently received an orthotopic liver transplant. We also present a review of the literature about the occurrence and treatment options for MVT.

Effect of N-Acetyltransferase 2 Genotype on the Pharmacokinetics of Hydralazine During Pregnancy

Hydralazine, an antihypertensive agent used during pregnancy, undergoes N-acetylation primarily via N-acetyltransferase 2 (NAT2) to form 3-methyl-1,2,4-triazolo[3,4-a]phthalazine (MTP). To characterize the steady-state pharmacokinetics (PK) of hydralazine during pregnancy and evaluate the effects of NAT2 genotype on hydralazine and MTP PK during pregnancy, 12 pregnant subjects received oral hydralazine (5-25 mg every 6 hours) in mid- (n = 5) and/or late pregnancy (n = 8). Serial blood samples were collected over 1 dosing interval, and steady-state noncompartmental PK parameters were estimated. Subjects were classified as either (rapid acetylators, n = 6) or slow acetylators (SAs, n = 6) based on NAT2 genotype. During pregnancy, when compared with the SA group, the RA group had faster weight-adjusted hydralazine apparent oral clearance (70.0 ± 13.6 vs 20.1 ± 6.9 L/h, P < .05), lower dose-normalized area under the concentration-time curve (AUC; 1.5 ± 0.8 vs 5.9 ± 3.7 ng·h/mL, P < .05), lower dose-normalized peak concentrations (0.77 ± 0.51 vs 4.04 ± 3.18 ng/mL, P < .05), and larger weight-adjusted apparent oral volume of distribution (302 ± 112 vs 116 ± 45 L/kg, P < .05). Furthermore, the MTP/hydralazine AUC ratio was ∼10-fold higher in the RA group (78 ± 30 vs 8 ± 3, P < .05) than in the SA group. No gestational age or dose-dependent effects were observed, possibly because of the small sample size. This study describes for the first time, the PK of oral hydralazine and its metabolite, MTP, during pregnancy, and confirmed that the PK of oral hydralazine is NAT2 genotype dependent during pregnancy.

Duration of cisplatin excretion in breast milk

Cisplatin, a platinum-based chemotherapy agent, is commonly used in treating cancers that may affect women of childbearing age, including cervical cancer, triple-negative breast cancer, and pediatric tumors in adolescents. The authors found that platinum was undetectable in breast milk at 66 hours and beyond following a 70-mg dose of intravenous cisplatin. Relative infant dose of platinum was calculated to be between 0.29% and 0.40% of the maternal dose corrected for body weight. This case demonstrates minimal exposure to platinum via breast milk, following a single 70-mg intravenous dose of cisplatin.

A Review of Inotropes and Inopressors for Effective Utilization in Patients With Acute Decompensated Heart Failure

ABSTRACT

Inotropes and inopressors are often first-line treatment in patients with cardiogenic shock. We summarize the pharmacology, indications, and contraindications of dobutamine, milrinone, dopamine, norepinephrine, epinephrine, and levosimendan. We also review the data on the use of these medications for acute decompensated heart failure and cardiogenic shock in this article.

Predictors of In-hospital Mortality in Cardiogenic Shock Patients on Vasoactive or Inotropic Support

Background:

Though controversial, the short-duration in-patient use of inotropes in cardiogenic shock (CS) remain an ACC/AHA Class IIa indication, and are frequently used in the initial treatment of CS. We evaluated in-patient mortality and effect on mortality risk of commonly used vasoactive inotropic medications for the medical management of SCAI stage B and C cardiogenic shock patients in a tertiary care cardiac care unit: dobutamine, dopamine, milrinone, and norepinephrine.

Methods:

We retrospectively evaluated 342 patients who received dobutamine, milrinone, dopamine, norepinephrine or a combination of these medications for SCAI stage B and C cardiogenic shock. Cox proportional hazards were used to form longitudinal mortality predictions.

Results:

Overall in-patient mortality was 18%. Each 1 µg/kg/minute increase in dobutamine independently corresponded to a 15% increase in risk of mortality. High dose dobutamine >3 µg/kg/minute is associated with 3-fold increased risk compared to ⩽3 µg/kg/minute (P < .001). Use of milrinone, norepinephrine, and dopamine were not independently associated with mortality.

Conclusion:

We demonstrate that the overall in-hospital mortality of SCAI stage B and C cardiogenic shock patients medically managed on inotropes was not in excess of prior studies. Dobutamine was independently associated with mortality, while other vasoactive inotropic medications were not. Inotropes remain a feasible method of managing SCAI stage B and C cardiogenic shock.

Association of Sacubitril/Valsartan with Metabolic Parameters in Patients with Reduced Ejection Fraction Heart Failure at a Multidisciplinary Clinic

Background: Sacubitril/valsartan was approved for New York Heart Association (NYHA) class II-IV heart failure with reduced ejection fraction (HFrEF) in 2015, based on the results of the PARADIGM-HF trial, which showed a reduction in cardiovascular (CV) death and heart failure hospitalization, compared with enalapril. A subsequent subgroup analysis of the trial showed glycemic improvement for patients on sacubitril/valsartan compared with those on enalapril. Methods: This was a retrospective observational study at the Loma Linda University (LLU) International Heart Institute (IHI). The aim was to evaluate the association of sacubitril/valsartan with glycemic index and other metabolic parameters, including change in hemoglobin A1C (HbA1C), blood pressure (BP), ejection fraction (EF), body weight, and lipid profile from baseline and at 3, 6, and 12 months. The rates of CV-related hospitalizations and total hospitalizations were also assessed. Results: The change in mean HbA1C from baseline was not significantly different at 1 year (P = 0.993). The mean EF was significantly higher and the mean diastolic BP was significantly lowered. Body weight and lipid parameters remained unchanged. Both the rates of CV-related hospitalizations and total hospitalizations were significantly lowered. For the prespecified subgroup analysis of diabetic HFrEF patients, the mean HbA1C was nonsignificant at 12 months (mean difference -0.48, P = 0.993). Conclusion: A non-significant reduction in HbA1C was associated in HFrEF patients with diabetes mellitus. Large randomized trials are needed to confirm our findings regarding the potential metabolic benefits of sacubitril/valsartan.

Critical Analysis of Apixaban Dose Adjustment Criteria

Apixaban is indicated for the prevention of ischemic stroke in non-valvular atrial fibrillation (NVAF), as well as for the prevention and treatment of venous thromboembolism (VTE). Dose adjustment is based on age, weight, and serum creatinine in NVAF, while there are no recommended adjustment criteria for VTE. Such adjustment is unconventional compared to other commonly used medications. The objective of this manuscript is to critically analyze each apixaban dosing adjustment criterion and its associated outcomes. PubMed articles from March 2013 to March 2020 were selected with search terms “apixaban,” and “dose adjustment,” “adjustment,” or “adjustment criteria.” Pharmacokinetic studies demonstrated increased apixaban exposure in patients >65 years of age, those with extreme body weights, and those with advanced renal impairment, though post-hemodialysis dosing may off-set the elevated apixaban exposure. However, clinical data show that among patients >75 years, <60 kg, and with estimated glomerular filtration rate <50 mL/min, including those on dialysis, there is no reduction in apixaban safety or efficacy. Published literature describes variable dosing strategies utilized in clinical practice. Overall, apixaban dose adjustment criteria may need to be re-evaluated.

Potential Association of Holidays on Internationalized Normalized Ratio in Warfarin-Users at a Multidisciplinary Clinic

Background

Warfarin is approved by the United States Food and Drug Administration for numerous clinical indications. The effectiveness of warfarin is highly dependent on the time-in-therapeutic range based on the international normalized ratio (INR) goal, which may be altered by changes in diet, alcohol intake, concomitant drugs, and travel, all of which are prevalent during the holidays. At this time, there are no published studies assessing the impact of holidays on INR in warfarin-users.

Methods

A retrospective chart review was conducted on all adult patients taking warfarin and managed at a multidisciplinary clinic. Patients were included if they were taking warfarin at home regardless of indication for anticoagulation. The INR pre- and post-holiday was assessed.

Results

Of a total of 92 patients, the mean age was 71.5 ± 14.3 years, and most patients were on warfarin with an INR goal of 2 - 3 (89%). There were significant differences in INR before and after Independence Day (2.55 vs. 2.81, P = 0.043) and Columbus Day (2.39 vs. 2.82, P < 0.001). The remaining holidays showed no significant differences in INR before and after each respective holiday.

Conclusions

There may be factors related to Independence and Columbus Day that are increasing the level of anticoagulation in warfarin-users. Although the mean post-holiday INR values, in essence, maintained within the typical target of 2 - 3, our study underscores the specialized care that is warranted in higher risk patients to prevent a continued increase in INR and subsequent toxicities. We hope our results would be hypothesis-generating and aid in the development of larger, prospective evaluations to validate the findings of our present study.