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result(s) for
"Lam, Edwin"
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Bidirectional pharmacokinetics of doravirine, tenofovir, and feminizing hormones in transgender women (IDentify): A randomized crossover trial
by
Lam, Kevin
,
Lam, Edwin
,
Kraft, Walter K.
in
17β-Estradiol
,
Acquired immune deficiency syndrome
,
AIDS
2024
Transgender women may have concerns of drug interactions between feminizing hormone therapy (FHT) and antiretrovirals, leading to nonadherence. This randomized, three‐period crossover, open‐label, phase I trial assessed the effects of doravirine (DOR) and tenofovir disoproxil fumarate (TDF) on the pharmacokinetics (PKs) of estradiol, spironolactone, and total testosterone and vice versa in healthy transgender women. Volunteers were randomized 1:1 into two sequences containing three treatment groups (DOR, lamivudine [3TC], and TDF alone; estradiol, spironolactone, and placebo; and DOR/3TC/TDF, estradiol, and spironolactone). Eight subjects enrolled in the study and six had completed all study periods. The geometric mean ratios for DOR area under the concentration‐time curve from zero to last measured concentration (AUC0‐last), maximum concentration (Cmax), and concentration at 24 h (C24) were similar. However, tenofovir (TFV) AUC0‐last, Cmax, and C24 moderately increased by 14%–38%. Last, estradiol AUC0‐last, Cmax, and C24 were increased by 10%–13%. Whereas most 90% confidence intervals did not meet the bioequivalence bounds of 80%–125%, the point estimates fell within the intervals. Log‐transformed DOR, TFV, and estradiol PK parameters computed with and without co‐administration were not statistically different (p > 0.05). There were no serious adverse events. There is not a clinically significant impact of FHT on DOR/TFV PKs. Similarly, there is no observed impact on estradiol PKs and total testosterone following use of DOR/3TC/TDF.
Journal Article
Longitudinal evaluation of azithromycin and cytokine concentrations in amniotic fluid following one‐time oral dosing in pregnancy
by
Roman, Amanda
,
Rochani, Ankit
,
Boelig, Rupsa C.
in
Adult
,
Amniotic fluid
,
Amniotic Fluid - chemistry
2021
To utilize noninvasive collection of amniotic fluid in the setting of preterm premature rupture of membranes (PPROMs) to report the time concentration profile of azithromycin in amniotic fluid over 7 days from a single dose, and evaluate the correlation between azithromycin concentration and inflammatory markers in amniotic fluid. Prospective cohort study of five pregnant patients admitted with PPROMs and treated with a single 1 g oral azithromycin dose. Amniotic fluid was collected from pads and used to quantify azithromycin concentration as well as TNFa, IL‐1a, IL‐1b, IL‐6, IL‐8, and IL‐10 concentrations. Primary outcome was time/concentration profile of azithromycin in amniotic fluid. Secondary outcome included correlation between azithromycin concentration and cytokine concentrations. Five patients were enrolled. Mean gestational age on admission with PPROM was 27.5 ± 2.3 weeks with a median latency of 7 days (interquartile range [IQR] = 4–13). A median of two samples/day (IQR = 1–3) were collected per participant. Azithromycin was quantified in duplicate; intra‐assay coefficient of variation was 17%. Azithromycin concentration was less than 60 ng/ml after day 3. Azithromycin concentration was positively correlated with IL‐8 (r = 0.38, p = 0.03), IL1a (r = 0.39, p = 0.03), and IL‐1b (r = 0.36, p = 0.04) in amniotic fluid. Azithromycin is detectable in amniotic fluid over 7 days from a single 1 g maternal dose, however, it is not sustained over the range of minimum inhibitory concentration for common genitourinary flora. Based on correlation with specific cytokines, azithromycin penetration in amniotic fluid may relate to maternal monocyte concentration in amniotic fluid in the setting of PPROM.
Journal Article
Intraperitoneal pharmacokinetics of vancomycin in patients on automated peritoneal dialysis
2022
It is unclear if the pharmacokinetics of vancomycin are the same during automated peritoneal dialysis (APD), where cycler exchanges may affect the systemic, peritoneal, and urinary disposition of drug. We conducted a prospective pharmacokinetic study evaluating the pharmacokinetics of vancomycin in plasma, dialysis fluid, and urine in peritonitis‐negative patients on APD. Patients underwent four drug‐free exchanges with 1.5% or 2.5% dextrose following the initial dwell period. Plasma, dialysis fluid, and urine was collected over the course of 7 days for pharmacokinetic analysis. Four patients completed the study with no adverse events. Following a median (range) dwell of 14.6 (14.2–17.6 h), the mean (±SD) observed maximum plasma concentration was 28.7 ± 4.9 mg/L with a mean bioavailability of 98.5 ± 1.4% prior to starting the cycler. The overall mean total plasma clearance estimated from study start to completion was 7.6 ± 1.2 ml/min. Mean total clearance during the dialytic exchange was 13.6 ± 4.9 ml/min. In patients with residual renal function, the mean vancomycin renal clearance was 3.1 ± 1.5 ml/min, representing 21.4%–58.9% of the overall total plasma clearance during the study period. Despite the small sample size, this pilot study suggests that the dwell time has important implications for systemic vancomycin exposure, time to therapeutic plasma concentration, and dosing. Dose is driven by dwell time, whereas the cycler determines the dosing interval. Rapid exchanges from APD will determine the frequency of dosing rather than the adequacy of absorption when vancomycin is given in the peritoneum.
Journal Article
Self-reported reactogenicity of CoronaVac (Sinovac) compared with Comirnaty (Pfizer-BioNTech): A prospective cohort study with intensive monitoring
by
Lai, Francisco Tsz Tsun
,
Cowling, Benjamin John
,
Huang, Lei
in
Allergic reactions
,
Allergy and Immunology
,
Chronic illnesses
2022
CoronaVac (Sinovac) Covid-19 vaccine has recently been approved for emergency use by the World Health Organization. However, data on its reactogenicity in real-world settings is scant. This study aimed to compare self-reported post-vaccination adverse reactions between CoronaVac and Comirnaty (Pfizer-BioNTech).
We adopted a prospective cohort study design using online surveys from the day of first-dose vaccination with intensive follow-up through two weeks after the second dose (11 time points). The primary outcome was adverse reactions (any versus none) and secondary outcomes were the sub-categories of adverse reactions (local, systemic, and severe allergic reactions). Potential effect modification across multimorbidity status, older age, and sex was examined.
In total, 2,098 participants who were scheduled to complete the 14th-day survey were included, with 46.2% receiving Comirnaty. Retention rate two weeks after the second dose was 81.0% for the CoronaVac group and 83.6% for the Comirnaty group. Throughout the follow-up period, 801 (82.7%) of those receiving Comirnaty and 543 (48.1%) of those receiving CoronaVac reported adverse reactions. Adjusted analysis suggested that compared with Comirnaty, CoronaVac was associated with 83%-reduced odds of any adverse reactions [adjusted odds ratio (AOR) = 0.17, 95% confidence interval (CI) 0.15–0.20], 92%-reduced odds of local adverse reactions (AOR = 0.08, 95% CI 0.06–0.09), and 76%-reduced odds of systemic adverse reactions (AOR = 0.24, 95% CI 0.16–0.28). No significant effect modification was identified.
This post-marketing study comparing the reactogenicity of Covid-19 vaccines suggests a lower risk of self-reported adverse reactions following vaccination with CoronaVac compared with Comirnaty.
Journal Article
Pharmacokinetics of Ketamine at Dissociative Doses in an Adult Patient With Refractory Status Asthmaticus Receiving Extracorporeal Membrane Oxygenation Therapy
by
West, Frances Mae
,
Hirose, Hitoshi
,
Lam, Edwin
in
acute respiratory distress syndrome
,
Adult
,
anesthetic
2019
First-line management of severe asthma exacerbations include the use of inhaled short-acting β-agonists, anticholinergics, and systemic corticosteroids. Continuous intravenous ketamine given at dissociative doses may be a pharmacologic option in patients who are intubated with life-threatening severe bronchospasm unresponsive to standard therapy. We describe the case of a 44-year-old man admitted to the intensive care unit for status asthmaticus requiring intubation and mechanical ventilation.
The patient developed severe refractory hypercapnic respiratory failure necessitating additional respiratory support with veno-venous extracorporeal membrane oxygenation (ECMO) therapy. Ketamine treatment was initiated at 0.5 mg/kg/h continuous infusion on the day of admission for pain control and required up-titration to 2 mg/kg/h by intensive care unit day 4 for bronchodilation. Whole blood samples were obtained for pharmacokinetic analysis of ketamine during ECMO.
The plasma concentration at steady state was 1018.7 ng/mL, with an estimated clearance of 1.96 L/kg/h after up-titration. The Vd was 14.18 L/kg, the ke was 0.14 hr−1, and the t½ was 5 hours.
Compared with healthy adults, there was a 6.5-fold increase in the Vd. However, the Vd was similar compared with critically ill patients not receiving ECMO. Further studies should focus on the effect of ECMO on ketamine pharmacokinetic properties.
Journal Article
Pharmacokinetics of apixaban in patients undergoing pancreaticoduodenectomy (PAP-UP)
2024
The impact of pancreaticoduodenectomy on absorption of drugs in the duodenum remains largely unknown. We aim to characterize the pharmacokinetics of apixaban in patients who had previously undergone pancreaticoduodenectomy.
A single 10-mg dose of apixaban was administered to 4 volunteers who underwent pancreaticoduodenectomy at least 6 months prior. The maximum plasma apixaban concentration (C
) and area under the plasma concentration time-curve (AUC
, AUC
) were compared against healthy historical control subjects (N = 12). Geometric mean ratios (GMR) with 90% confidence interval (CI) were calculated for determination of comparative bioequivalence.
In pancreaticoduodenectomy patients, AUC
and AUC
were 1,861 and 2,080 ng×h/mL, respectively. The GMRs of AUC
and AUC
between study subjects and healthy controls were 1.27 (90% CI 0.88 - 1.83) and 1.18 (90% CI 0.82 - 1.72). The mean C
of apixaban was 201 ng/mL (SD 15.6) occurring at a median t
of 3.25 hours (range 2.5 - 4 hours). The GMR of C
between study subjects and healthy controls was 1.12 (90% CI 0.77 - 1.63).
The pharmacokinetic characteristics of apixaban in subjects who had undergone pancreaticoduodenectomy are not significantly different from those of healthy controls. Though the sample size of this study is small, results suggest that no change to apixaban dose regimen is needed in patients who have had a pancreaticoduodenectomy.
Journal Article
Population pharmacokinetic and safety analysis of ropivacaine used for erector spinae plane blocks
by
Witzeling, Scott D
,
Sarna, Rohan R
,
Viscusi, Eugene R
in
Acute Pain
,
Anesthesia
,
Anesthesia, Local
2023
IntroductionErector spinae plane blocks have become popular for thoracic surgery. Despite a theoretically favorable safety profile, intercostal spread occurs and systemic toxicity is possible. Pharmacokinetic data are needed to guide safe dosing.MethodsFifteen patients undergoing thoracic surgery received continuous erector spinae plane blocks with ropivacaine 150 mg followed by subsequent boluses of 40 mg every 6 hours and infusion of 2 mg/hour. Arterial blood samples were obtained over 12 hours and analyzed using non-linear mixed effects modeling, which allowed for conducting simulations of clinically relevant dosing scenarios. The primary outcome was the Cmax of ropivacaine in erector spinae plane blocks.ResultsThe mean age was 66 years, mean weight was 77.5 kg, and mean ideal body weight was 60 kg. The mean Cmax was 2.5 ±1.1 mg/L, which occurred at a median time of 10 (7–47) min after initial injection. Five patients developed potentially toxic ropivacaine levels but did not experience neurological symptoms. Another patient reported transient neurological toxicity symptoms. Our data suggested that using a maximum ropivacaine dose of 2.5 mg/kg based on ideal body weight would have prevented all toxicity events. Simulation predicted that reducing the initial dose to 75 mg with the same subsequent intermittent bolus dosing would decrease the risk of toxic levels to <1%.ConclusionLocal anesthetic systemic toxicity can occur with erector spinae plane blocks and administration of large, fixed doses of ropivacaine should be avoided, especially in patients with low ideal body weights. Weight-based ropivacaine dosing could reduce toxicity risk.Trial registration number NCT04807504; clinicaltrials.gov.
Journal Article
Twice‐Daily Doravirine Overcomes the Interaction Effect from Once‐Weekly Rifapentine and Isoniazid in Healthy Volunteers
by
Zheng, Richard
,
Schaefer, Joseph
,
Lam, Edwin
in
Antibiotics
,
Antiretroviral drugs
,
Body mass index
2020
Doravirine (DOR) is a non‐nucleoside reverse transcriptase inhibitor indicated for the treatment of HIV‐1. Its use in combination with rifapentine (RPT), an antituberculosis (TB) antibiotic, may reduce the exposure of DOR compromising viral suppression in those living with HIV‐1 co‐infected with TB. We conducted a prospective, phase I, open label, two‐period, fixed sequence, drug interaction study to evaluate the effect of once‐weekly RPT and isoniazid (INH) on the pharmacokinetics (PKs) of DOR in healthy volunteers. DOR 100 mg was administered alone twice‐daily for 4 days in period 1. In period 2, once‐weekly RPT + INH were co‐administered with multiple doses of DOR 100 mg twice‐daily for study days 7, 14, and 21. Plasma was obtained for DOR PKs when given alone and co‐administered with RPT + INH. Eleven healthy volunteers enrolled and completed the study. The geometric mean ratios and 90% confidence intervals for DOR area under the concentration‐time curve from zero to 12 hours (AUC0–12) and C12 in the presence of RPT + INH compared with DOR alone were 0.71 (0.60–0.85) and 0.69 (0.54–0.89), respectively. Although exposures were moderately reduced in the presence of RPT + INH, trough DOR values were within the concentration range associated with virological suppression. These results demonstrate that a modest decrease in DOR exposure would unlikely be clinically relevant in a virally suppressed patient co‐administered once‐weekly RPT + INH.
Journal Article
Unnecessary Tests and Procedures in Patients Presenting with Solid Tumors of the Pancreas
2013
Background
A computed tomography (CT) scan is often the only study needed prior to surgery for resectable solid pancreas masses. However, many patients are evaluated with multiple studies and interventions that may be unnecessary.
Methods
We conducted a retrospective review of patients who presented to the Johns Hopkins Multidisciplinary Pancreas Cancer Clinic with a clearly resectable solid pancreas mass, >1 cm in size over a 2-year period (6/2007–6/2009) and underwent resection. Pancreas specialists reviewed patient records and identified an index CT with a solid pancreas mass deemed to be resectable for curative intent. Data were collected on all studies and interventions between the index CT and the surgery.
Results
A total of 101 patients had an index CT. Following the index CT and before surgery, 78 patients had at least one CT, 19 had magnetic resonance imaging, 9 had a positron emission tomography scan, and 66 underwent pancreatic biopsy. Patients underwent a mean of three studies with a mean added cost of $3,371 per patient. Preoperative tests and interventions were associated with a longer time to definitive surgical intervention.
Conclusion
Wide variation exists for evaluation of newly discovered resectable solid pancreas masses, which is associated with delays to surgical intervention and added costs.
Journal Article