Retrospective Evaluation of Drug-Drug Interactions With Erlotinib and Gefitinib Use in the Military Health System.

Background: Erlotinib and gefitinib are epidermal growth factor receptor-tyrosine kinase inhibitors approved for non-small cell lung cancer treatment by the US Food and Drug Administration. Drug-drug interactions (DDIs) with these agents are vague and poorly understood. Because DDIs can have an effect on clinical outcomes, we aimed to identify drugs that interact with erlotinib or gefitinib and describe their clinical manifestations. Methods: A retrospective analysis was performed on the health records of patients in the US Department of Defense Cancer Registry (retrieved September 2021), Comprehensive Ambulatory/Professional Encounter Records, and Pharmacy Data Transaction Service database (both retrieved May 2022). Patients' medical history, diagnoses, and demographics were extracted and analyzed for differences in adverse effects when these agents were used alone vs concomitantly with other prescription drugs. Patients' diagnoses and prescription drug use were extracted to compare completed vs discontinued treatment groups, identify medications commonly co-administered with erlotinib or gefitinib, and evaluate DDIs with antidepressants. Results: Of 387 patients using erlotinib, 264 completed treatments; 28 of 33 patients using gefitinib completed treatment. The P value for erlotinib discontinuation when used alone vs concomitantly was < .001, and the P value for gefitinib discontinuation was .06. Patients who took erlotinib or gefitinib concomitantly with a greater number of prescription drugs had a higher rate of treatment discontinuation than those who received fewer medications. Patients in the completed group received 1 to 75 prescription drugs, and those in the completed group were prescribed 3 to 103. Those who discontinued treatment had more diagnosed medical issues than those who completed treatment. Conclusions: This review cannot conclude that concomitant use with prescription drug(s) resulted in erlotinib or gefitinib discontinuation. There were no significant DDIs determined between erlotinib or gefitinib and antidepressants.

Pre-clinical drug-drug interactions (DDIs) of gefitinib with/without losartan and selective serotonin reuptake inhibitors (SSRIs): citalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, and venlafaxine.

Objective: To evaluate drug-drug interactions (DDIs) between gefitinib with/without losartan and selective serotonin reuptake inhibitors (SSRIs). Methods: In vitro supersomes were used to identify CYP isoenzymes (CYP1A2, 2C9, 2C19, 2D6, and 3A4) involved in drug metabolism, and in vitro pooled cryopreserved primary human hepatocytes were employed to investigate DDIs. Results: The isoenzymes that showed drug degradation are listed in parentheses beside the respective drug: gefitinib (CYP2D6, 3A4, 1A2, 2C9, and 2C19), losartan (CYP2C9 and 3A4), citalopram (CYP2D6, 2C19, 3A4, and 2C9), fluoxetine (CYP2D6, 2C9, and 2C19), fluvoxamine (CYP2D6, 2C9, and 2C19), paroxetine (CYP2D6, 3A4, and 2C9), sertraline (CYP2D6, 2C9, 2C19, 1A2, and 3A4), and venlafaxine (CYP2D6 and 2C19).DDIs from human hepatocytes assays revealed that gefitinib had significant metabolic changes in (1:1) combination with paroxetine or sertraline (p-value â€‹= â€‹0.042 and 0.025 respectively) and (1:1:1) combination with losartan and fluoxetine, fluvoxamine, paroxetine, or sertraline (p-value â€‹= â€‹0.009, 0.027, 0.048, and 0.037 respectively). Losartan showed significant changes in (1:1:1) combination with gefitinib and fluoxetine or sertraline (p-value â€‹= â€‹0.026 and 0.008 respectively). Fluoxetine, fluvoxamine, and paroxetine underwent significant changes in (1:1:1) combination with gefitinib and losartan (p-value â€‹= â€‹0.003, 0.022, and 0.046 respectively). Sertraline had significant changes within all combinations: DDIs with gefitinib alone and in combination with gefitinib and losartan (p-value â€‹= â€‹0.009 and 0.008 respectively). Citalopram and venlafaxine appeared to be unaffected by any combination. Conclusion: The study provides a clear proof-of concept for in vitro metabolic DDI testing. While identifying compounds by their inhibition potential can help better predict their metabolism, it cannot resolve problems that arise from DDIs since the overall degree of effectiveness is unknown. As shown in this study, gefitinib has been identified as a weak CYP2C19 and 2D6 inhibitor, however, gefitinib can have significant DDIs with sertraline. Furthermore, multiple drug combinations (1:1:1) can change the significance of previously determined DDIs in (1:1) combination. Thus, in vitro assays can potentially provide better guidance for multidrug regimens with minimal risk for DDIs.

Real World Impact of Remdesivir and Dexamethasone on Clinical Outcomes of Severe Coronavirus Disease 2019 in a Community Hospital.

BACKGROUND: Evidence has emerged showing potential benefit of Remdesivir and dexamethasone in severe coronavirus disease 2019 (COVID-19) but results from large randomized control trials are conflicting. While initial data for dexamethasone indicated a mortality benefit, the impact of Remdesivir was best demonstrated in decreased time to recovery. Despite extensive disease burden throughout the world efficacy data of individual interventions is lacking in part due to extensive concurrent use of confounding investigational therapeutics. MATERIALS AND METHODS: We performed a retrospective analysis of the impact of Remdesivir and dexamethasone on real-world outcomes in severe COVID-19. All patients admitted to our community hospital between March 2020 and December 31, 2020 were included, and all patients admitted before national guidelines endorsed Remdesivir and dexamethasone outside of clinical trials were treated with only supportive care and used as historical controls. No other investigational therapeutics were utilized. This study was reviewed and approved by the Fort Belvoir Community Hospital IRB. RESULTS: 58 hospitalized patients met criteria for severe COVID-19 as confirmed by RT-PCR, and 14 (25%) were used as historical controls. Baseline demographics and overall mortality rate (7.1%) did not significantly differ between the groups. The median length of stay was 7 days and 6 days in the historical control group and interventional group, respectively (P = 0.55). CONCLUSIONS: We did not observe an appreciable impact on the duration of hospitalization when Remdesivir and dexamethasone were added to supportive care in a community hospital. This study was not sufficiently powered to detect the previously described mortality benefit of dexamethasone.

Clinical Outcomes of Coronavirus Disease 2019 With Evidence-based Supportive Care.

Calls for adherence to evidence-based medicine have emerged during the initial wave of the COVID-19 pandemic but reports of outcomes are lacking. This retrospective study of an institutional cohort including 135 patients with confirmed COVID-19 demonstrates positive outcomes when organizational standards of care consist of evidence-based supportive therapies.

Pre-clinical drug-drug interaction (DDI) of gefitinib or erlotinib with Cytochrome P450 (CYP) inhibiting drugs, fluoxetine and/or losartan.

OBJECTIVE: To evaluate drug-drug interactions (DDIs) between gefitinib or erlotinib with fluoxetine, and/or losartan. METHODS: Human pooled microsomes, supersomes, and cryopreserved human hepatocytes were used to monitor DDIs in vitro. RED (Rapid Equilibrium Dialysis) protein binding was employed to investigate other pharmacokinetics. RESULTS: Gefitinib is significantly metabolized by Cytochrome P450 (CYP) 2D6 and CYP3A4, with less than 80% of the drug remaining. Erlotinib is significantly metabolized by CYP3A4, CYP2D6, and CYP1A2. Although gefitinib and erlotinib were metabolized by the same CYP isoenzymes, the metabolites formed from degradation of the two drugs were different.Fluoxetine inhibited CYP2D6 and CYP3A4 metabolism of gefitinib with an IC50 of 65.12 ± 1.88 µM and 4.11 ± 2.26 µM, respectively. Fluoxetine also inhibited CYP2D6 and CYP3A4 metabolism of erlotinib with an IC50 of 7.06 ± 1.54 µM and 4.57 ± 1.22 µM, respectively.For hepatocytes, fluoxetine affected the metabolism of gefitinib or erlotinib, while losartan had no effect. Gefitinib and erlotinib inhibited the metabolism of fluoxetine and losartan. Two-drug combinations involving gefitinib or erlotinib with fluoxetine or losartan yielded insignificant (p-value ≥ 0.05) differences in metabolism. However, combinations involving three drugs yielded significant degrees of inhibition (p-value ≤ 0.05). Three drug combinations involving fluoxetine and losartan with gefitinib or erlotinib yielded significant degrees of inhibition of the metabolism of gefitinib, but not for that of erlotinib. CONCLUSION: As could be predicted by previous studies involving the inhibitory effect of fluoxetine on CYP3A4 and CYP2D6, and studies involving CYP metabolism of gefitinib and erlotinib, the tests performed here confirmed that fluoxetine has an inhibitory effect on metabolism of gefitinib or erlotinib by the main CYP isoenzymes involved. This study suggests a variable inhibitory effect of fluoxetine particularly on CYP2D6 activity towards gefitinib or erlotinib; erlotinib metabolism is less affected. Likewise, the combination of fluoxetine and losartan does not significantly affect hepatocyte metabolism of erlotinib, but does for that of gefitinib. The results presented in this study thus indicate a need for DDI assays to involve multiple drugs to properly study multidrug regimens.

Topical paromomycin for New World cutaneous leishmaniasis.

BACKGROUND: Paromomycin-based topical treatments were shown to be effective in curing cutaneous leishmaniasis (CL) lesions caused by Leishmania major in Tunisia. Cure rates of an index lesion were approximately 80%. As a follow on, we conducted a similar Phase 3 trial in Panama to demonstrate the efficacy of these treatments against New World species. The primary objective was to determine if a combination topical cream (paromomycin-gentamicin) resulted in statistically superior final clinical cure rates of an index lesion compared to a paromomycin alone topical cream for the treatment of CL, primarily caused by Leishmania panamensis. METHODS: We conducted a randomized, double blind, Phase 3 trial of topical creams for the treatment of CL caused by Leishmania spp. Three hundred ninety nine patients with one to ten CL lesions were treated by topical application once daily for 20 days. The primary efficacy endpoint was percentage of subjects with clinical cure of an index lesion confirmed to contain Leishmania with no relapse. RESULTS: The clinical cure of the index lesion for paromomycin-gentamicin was 79% (95% CI; 72 to 84) and for paromomycin alone was 78% (95% CI; 74 to 87) (p = 0.84). The most common adverse events considered related to study cream application were mild to moderate dermatitis, pain, and pruritus. CONCLUSIONS: Superiority of paromomycin-gentamicin was not demonstrated. However, the approximately 80% cure rates for both topical creams were similar to those demonstrated in Tunisia and previously reported with parenteral antimonials.

A simple empirical algorithm to distinguish among Leishmania braziliensis, major, and tropica species by MALDI-TOF mass spectrometry.

This work developed a simple empirical algorithm to distinguish three Leishmania species using MALDI-TOF mass spectrometry. It suggests that complicated computer algorithms may not always be necessary for clinically useful microbiology applications.

Comparative pharmacokinetics and pharmacodynamics of intravenous artelinate versus artesunate in uncomplicated Plasmodium coatneyi-infected rhesus monkey model.

BACKGROUND: The US Army designed artelinate/lysine salt (AL) to overcome the instability of sodium artesunate in aqueous solution (AS). To select the most efficacious artemisinin treatment, direct comparison was performed in an uncomplicated non-human primate malaria model. METHODS: Splenectomized rhesus monkeys were inoculated with Plasmodium coatneyi and on day six, single equimolar loading dose of IV AL (11.8 mg kg(-1)) or IV AS (8 mg kg(-1)) were administered followed by 1/2 the first dose once daily for 2 more days. Blood smear were performed twice daily and the number of parasites were counted microscopically. Blood samples were obtained after the first dose within 6 h for pharmacokinetic (PK) and ex vivo pharmacodynamic evaluation by simultaneously measuring plasma drug concentration and anti-malarial activity against Plasmodium falciparum in vitro. RESULTS: The anti-P. coatneyi in vivo activity of both compounds were comparable, but the ex vivo anti-P. falciparum potency of the IV AS regimen as administered was sevenfold higher than that of IV AL. Comparing in vivo pharmacodynamics of AL and AS, daily assessed parasite counts showed comparable 99 % parasite clearance times (PC99: 2.03, 1.84 day), parasite clearance rates (5.34, 4.13 per min) and clearance half-life (PCt1/2: 7.79, 10.1 h). This study showed strong and significant inverse correlation between PCt1/2 and t1/2 of AS + DHA, and AUC0-∞ of DHA, and correlated with Vz of AS (r(2) > 0.7, p ≤ 0.002). Lastly, following IV AL, there was a modest inverse correlation between PCt1/2 and Cmax (r(2) 0.6, p ≤ 0.04). Although all tested monkeys recrudesced subsequently, two died following AL regimen before parasite clearance. While the aetiology of those deaths could not be definitively determined, pathologic evidence favoured a sepsis-like syndrome and suggested that severe malaria was more likely than drug toxicity. CONCLUSION: The model demonstrated that both AS and DHA contributed to the anti-malarial activity of IV AS, while IV AL activity was largely restricted to the parent drug. Parasite clearance was strongly and linearly dependent on drug exposure for both artemisinin regimens. However, IV AS had higher ex vivo potency against P. falciparum, leading to an IND filing for GMP manufactured AS in the United States.

Pharmacokinetic evaluation of intravenous artesunate in adults with uncomplicated falciparum malaria in Kenya: a phase II study.

BACKGROUND: Alternatives to treatment for malaria treatment of travellers are needed in the USA and in Europe for travellers who return with severe malaria infections. The objective of this study is to show the pharmacokinetic (PK) profile of intravenous artesunate (AS), which was manufactured under good manufacturing practice (GMP) conditions, in adults with uncomplicated falciparum malaria in Kenya. METHODS: The PK parameters of intravenous AS manufactured under current cGMP were evaluated after a single dose of drug at 2.4 mg/kg infused over 2 min in 28 adults with uncomplicated Plasmodium falciparum malaria. Plasma concentrations of AS and dihydroartemisinin (DHA) were measured using a validated liquid chromatography-mass spectrometry (LC-MS/MS) methodology. Pharmacokinetic data were analysed with a compartmental analysis for AS and DHA. RESULTS: The results suggest there were no drug-related adverse events in any of the patients. After intravenous infusion, the concentration of the parent drug rapidly declined, and the AS was converted to DHA. AS and DHA showed mean elimination half-lives of 0.17 hours and 1.30 hours, respectively. The high mean peak concentration (Cmax) of AS was shown to be 28,558 ng/mL while the Cmax of DHA was determined to be 2,932 ng/mL. Significant variability was noted in the PK profiles of the 28 patients tested. For example, Cmax values of AS were calculated to range from 3,362 to 55,873 ng/mL, and the Cmax value of DHA was noted to vary from 1,493 to 5,569 ng/mL. The mean area under the curve (AUC) of AS was shown to be approximately half that of DHA (1,878 ng · h/mL vs 3,543 ng · h/mL). The DHA/AS ratio observed was 1.94 during the one-day single treatment, and the AUC and half- life measured for DHA were significantly larger and longer than for AS. CONCLUSIONS: Intravenous AS can provide much higher peak concentrations of AS when compared to concentrations achieved with oral therapy; this may be crucial for the rapid elimination of parasites in patients with severe malaria. Given the much longer half-life of DHA compared to the short half-life of AS, DHA also plays a significant role in treatment of severe malaria.

Use of qPCR and genomic sequencing to diagnose Plasmodium ovale wallikeri malaria in a returned soldier in the setting of a negative rapid diagnostic assay.

Plasmodium ovale is one of several clinically relevant malaria species known to cause disease in humans. However, in contrast to Plasmodium falciparum and Plasmodium vivax, which are responsible for most cases of human malaria, P. ovale has a wide distribution but low prevalence in tropical regions. Here, we report the case of a soldier returning from Liberia with P. ovale wallikeri malaria. This case highlights the limitations of both microscopy and the malaria rapid diagnostic test for diagnosing infection with P. ovale and for distinguishing P. ovale wallikeri from P. ovale curtisi. To our knowledge, this is the first case report in which quantitative real-time polymerase chain reaction amplification using the Cytochrome B gene, coupled with genomic sequencing of the potra locus, was used for definitive diagnosis of P. ovale wallikeri malaria.

Texting away malaria: a new alternative to directly observed therapy.

OBJECTIVE: Operation Onward Liberty is the current U.S. military mentorship program working with the Armed Forces of Liberia, training their national army. Throughout West Africa, and Liberia in particular, malaria remains a serious health concern. This is a critical concern to all U.S. Forces deployed in areas endemic with malaria. In January 2011, a new protocol was instituted among Operation Onward Liberty members using short message service (SMS) technology to ensure 100% daily accountability. METHODS: Beginning in January 2011, SMS was used to report completion of daily ingestion of malaria chemoprophylaxis by U.S. Forces in Liberia. RESULTS: Since then, there were no cases of malaria identified by both Binax rapid diagnostic test and thin smear. The previous year (2010) saw 12 cases of malaria among U.S. Forces in Liberia (9 during the same 6-month period), with 3 evacuations for malaria, costing an estimated 1.5 million dollars. CONCLUSIONS: Although directly observed therapy is still the gold standard of malaria chemoprophylaxis, use of cellular telephone texting technology, or SMS, for communicating ingestion may be the best alternative for reasonable accountability in the deployed setting, especially considering the highly decentralized nature of this and other deployment locations.

Visceral leishmaniasis with associated immune dysregulation leading to lymphoma.

OBJECTIVE: We describe an atypical presentation of visceral leishmaniasis (VL) complicated by Epstein-Barr virus (EBV)-lymphoproliferative disorder and angioimmunoblastic T-cell lymphoma in a U.S. Government contractor recently deployed to Iraq and Afghanistan. METHODS: We performed a search of PubMed (1966-2012) using the terms visceral, leishmaniasis, operation, iraqi, freedom, desert, storm, EBV, lymphoproliferative, angioimmunoblastic, and lymphoma. The purpose of the search was two-fold: to find reported cases of VL during U.S. military operations and to ascertain if lymphoproliferative disorder (specifically, because of EBV) was ever described as a sequelae of VL. RESULTS: Case series of VL acquired in the Middle East between 1990 and 2012 showed that while fever, abdominal pain, and hepatosplenomegaly were common signs and symptoms of VL, diffuse lymphadenopathy (our patient's presentation) was rare. Moreover, VL in and of itself lends to profound immune dysregulation, leading to a myriad of complications to include EBV-lymphoproliferative diseases. CONCLUSIONS: Diffuse lymphadenopathy because of VL is a very atypical presentation for infection acquired in the Middle East. Clinicians must be mindful of the extreme immune dysfunction that occurs as a result of this potentially fatal infection and the associated complications to include EBV-related lymphoproliferative disorders and lymphoma.

An in vivo drug screening model using glucose-6-phosphate dehydrogenase deficient mice to predict the hemolytic toxicity of 8-aminoquinolines.

Anti-malarial 8-aminoquinolines drugs cause acute hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDD). Efforts to develop non-hemolytic 8-aminoquinolines have been severely limited caused by the lack of a predictive in vivo animal model of hemolytic potential that would allow screening of candidate compounds. This report describes a G6PDD mouse model with a phenotype closely resembling the G6PDD phenotype found in the African A-type G6PDD human. These G6PDD mice, given different doses of primaquine, which used as a reference hemolytic drug, display a full array of hemolytic anemia parameters, consistently and reproducibly. The hemolytic and therapeutic indexes were generated for evaluation of hemotoxicity of drugs. This model demonstrated a complete hemolytic toxicity response to another known hemolytic antimalarial drug, pamaquine, but no response to non-hemolytic drugs, chloroquine and mefloquine. These results suggest that this model is suitable for evaluation of selected 8-AQ type candidate antimalarial drugs for their hemolytic potential.

Significance of infectious agents in colorectal cancer development.

Colorectal cancer (CRC) is a major burden to healthcare systems worldwide accounting for approximately one million of new cancer cases worldwide. Even though, CRC mortality has decreased over the last 20 years, it remains the third most common cause of cancer-related mortality, accounting for approximately 600,000 deaths in 2008 worldwide. A multitude of risk factors have been linked to CRC, including hereditary factors, environmental factors and inflammatory syndromes affecting the gastrointestinal tract. Recently, various pathogens were added to the growing list of risk factors for a number of common epithelial cancers, but despite the multitude of correlative studies, only suggestions remain about the possible relationship between selected viruses and bacteria of interest and the CRC risk. United States military service members are exposed to various risk factors impacting the incidence of cancer development. These exposures are often different from that of many sectors of the civilian population. Thereby, cancer risk identification, screening and early detection are imperative for both the military health care beneficiaries and the population as a whole. In this review, we will focus on several pathogens and their potential roles in development of CRC, highlighting the clinical trials evaluating this correlation and provide our personal opinion about the importance of risk reduction, health promotion and disease prevention for military health care beneficiaries.

Pharmacokinetic profiles of artesunate following multiple intravenous doses of 2, 4, and 8 mg/kg in healthy volunteers: phase 1b study.

BACKGROUND: Severe malaria results in over a million deaths every year, most of them in children aged less than five years and living in sub-Saharan Africa. Injectable artesunate (AS) was recommended as initial treatment for severe malaria by WHO in 2006. The Walter Reed Army Institute of Research (WRAIR) has been developing a novel good manufacturing practice (GMP) injection of AS, which was approved by the US FDA for investigational drug use and distribution by the CDC. METHODS: Tolerability and pharmacokinetics of current GMP intravenous AS, as an anti-malarial agent, were evaluated after ascending multiple doses of 2, 4, and 8 mg/kg daily for three days with 2-minute infusion in 24 healthy subjects (divided into three groups) in the Phase 1 clinical trial study. RESULTS: Results showed that there were no dose-dependent increases in any adverse events. Drug concentrations showed no accumulation and no decline of the drug during the three days of treatment. After intravenous injection, parent drug rapidly declined and was converted to dihydroartemisinin (DHA) with overall mean elimination half-lives ranging 0.15-0.23 hr for AS and 1.23-1.63 hr for DHA, but the peak concentration (C(max)) of AS was much higher than that of DHA with a range of 3.08-3.78-folds. In addition, the AUC and C(max) values of AS and DHA were increased proportionally to the AS climbing multiple doses. DISCUSSION: The safety of injectable AS, even at the highest dose of 8 mg/kg increases the probability of therapeutic success of the drug even in patients with large variability of parasitaemia.

Improvement of anti-Burkholderia mouse monoclonal antibody from various phage-displayed single-chain antibody libraries.

To improve anti-Burkholderia monoclonal antibody (MAb) binding affinity, six single chain variable fragments (scFvs) constructed previously were used as scaffolds to construct large highly-diversified phage-displayed mouse scFv random and domain libraries. First, we employed random mutagenesis to introduce random point mutations into entire variable regions, generating six random libraries. Additionally, the oligonucleotide-directed mutagenesis was targeted on complementarity-determining region 3 (CDR3) from each variable region of heavy (VH) and light chains (VL) derived from six scFvs, and generated eighteen domain libraries including six VH CDR3, six VL CDR3, and six combined VH/VL CDR3 mutated domains, respectively. We collected high scFvs binders through panning experiment over the large (size ~1 × 109) random and domain libraries. The quality of the libraries was validated by successful selection of high-affinity clones. Random mutagenesis generated many mutant scFv clones having more than one amino acid changes around framework regions, but not many in CDRs. Surprisingly, the resulting eight higher scFv binders were selected from CDR3 mutations, but not from random mutations. Six of them resulted from CDR3 mutations of light chain, except for two scFvs from heavy chain, showing both Burkholderia pseudomallei and Burkholderia mallei had preferentially influenced the VL CDR3. Furthermore, all eight higher scFvs converted to full format human IgG1 antibodies were expressed transiently in 293T cell line. Five chimeric MAbs showed improved higher binding activity, as much as 0.2-0.3 at O.D. 405 nm, than positive control MAbs. These libraries could be valuable sources for selection of anti-Burkholderia antibodies and discovery of the relevant epitope(s) for developing effective vaccines or therapeutics.