scholarly journals Current therapeutic applications and pharmacokinetic modulations of ivermectin

2019 ◽  
Vol 12 (8) ◽  
pp. 1204-1211 ◽  
Author(s):  
Khan Sharun ◽  
T. S. Shyamkumar ◽  
V. A. Aneesha ◽  
Kuldeep Dhama ◽  
Abhijit Motiram Pawde ◽  
...  

Ivermectin is considered to be a wonder drug due to its broad-spectrum antiparasitic activity against both ectoparasites and endoparasites (under class of endectocide) and has multiple applications in both veterinary and human medicine. In particular, ivermectin is commonly used in the treatment of different kinds of infections and infestations. By altering the vehicles used in the formulations, the pharmacokinetic properties of different ivermectin preparations can be altered. Since its development, various vehicles have been evaluated to assess the efficacy, safety, and therapeutic systemic concentrations of ivermectin in different species. A subcutaneous route of administration is preferred over a topical or an oral route for ivermectin due to superior bioavailability. Different formulations of ivermectin have been developed over the years, such as stabilized aqueous formulations, osmotic pumps, controlled release capsules, silicone carriers, zein microspheres, biodegradable microparticulate drug delivery systems, lipid nanocapsules, solid lipid nanoparticles, sustained-release ivermectin varnish, sustained-release ivermectin-loaded solid dispersion suspension, and biodegradable subcutaneous implants. However, several reports of ivermectin resistance have been identified in different parts of the world over the past few years. Continuous use of suboptimal formulations or sub-therapeutic plasma concentrations may predispose an individual to resistance toward ivermectin. The current research trend is focused toward the need for developing ivermectin formulations that are stable, effective, and safe and that reduce the number of doses required for complete clinical cure in different parasitic diseases. Therefore, single-dose long-acting preparations of ivermectin that provide effective therapeutic drug concentrations need to be developed and commercialized, which may revolutionize drug therapy and prophylaxis against various parasitic diseases in the near future. The present review highlights the current advances in pharmacokinetic modulation of ivermectin formulations and their potent therapeutic applications, issues related to emergence of ivermectin resistance, and future trends of ivermectin usage. Keywords: ivermectin, ivermectin resistance, pharmacokinetic modulation, therapeutic applications.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4820-4820 ◽  
Author(s):  
Carolyn Blasdel ◽  
Yanfeng Wang ◽  
Theodore Lagattuta ◽  
Brian Druker ◽  
Laurie Letvak ◽  
...  

Abstract OBJECTIVES: Imatinib (IM) has demonstrated durable clinical efficacy in the majority of chronic myeloid leukemia (CML) patients. Optimal response may be influenced by multiple innate and external factors, some of which may be controlled by monitoring plasma concentrations of the drug. This abstract reports 6 cases where analyzing plasma IM trough concentrations (Cmin) in patients treated with three commonly used IM doses (400, 600, and 800 mg daily) influenced clinical decision making. METHODS: IM trough blood samples were collected at a time before that day’s IM dosing. Plasma concentrations of IM were determined by a validated LC/MS/MS method. RESULTS: In large population studies of CML patients enrolled in Phase I, II, and III clinical trials, the mean Cmin levels of IM at 400 mg qd, 600 mg qd, and 400 mg bid doses were: 981 (±543, 55%, n=394), 1572 (±1032, 66%, n=14), and 3479 (±1264, 36%, n=14) ng/mL, respectively. Large inter-patient variability was shown at all three doses. Of the 6 cases detailed in the table below, 4 (ID 1, 3, 4, and 5) had dose reduction due to tolerability concerns with subsequent improvement of symptoms following dose adjustment. One patient (ID 2) had a dose increase because of a poor qRT-PCR response. Another (ID 6) had a dose increase due to low plasma IM exposure resulting from drug-drug interaction with phenytoin, a known inducer of CYP3A4 (the major metabolizing isozyme for IM). After dose adjustment, all six patients showed good clinical response to IM treatment. The new mean Cmin value in these patients was 2000 (±471) ng/mL, representing a 24% coefficient of variability. CONCLUSIONS: Although the data is limited, IM drug monitoring proved useful in managing tolerability, lack of efficacy, adherence or potential drug interactions that modulate imatinib drug concentrations. More prospective studies are needed to demonstrate the value of IM drug monitoring in routine clinical practice. Patient ID Age, Sex CML Stage IM Daily Dose 1st Cmin (ng/mL) Reason for Dose Change New Dosing Regimen New Cmin (ng/mL) CP, chronic phase1 1 54, f CP 200 mg bid, Jan 03 3048, Sep 05 transfusion-dependent, anemia, Sep 05 300 mg, Oct 05 2130, Jan 06 2 9, f CP 300 mg, Jan 05 not done qRT-PCR 0.016, Jan 06 400 mg, Jan 06 2341, Jul 06 3 13, f CP 300 mg bid, May 05; 700 mg, Aug 05; 600 mg, Sep 05 1966, Feb 06 nausea, fatigue, arthralgias, myalgia, ongoing 400 mg, Mar 06 1222, May 06 4 67, f CP 400 mg, Feb 05 not done myelosuppression, Mar 05 200 mg, Mar 05 1928, May 06 5 53, f CP 400 mg, Apr 03; 600 mg, May 03; 800 mg, Jul 04 not done inflammatory pulmonary reaction with shortness of breath; dose held, Mar 05 400 mg, Oct 05 2378, May 06 6 73, m CP 350 mg, on phenytoin, Apr 99 35, Jun 99 stopped phenytoin, Jul 99 500 mg, Jul 99 not done; qRT-PCR negative, Jul 06


2021 ◽  
Vol 7 ◽  
Author(s):  
Salah Uddin Ahmad ◽  
Jichao Sun ◽  
Fusheng Cheng ◽  
Bing Li ◽  
Safia Arbab ◽  
...  

A comparative study on pharmacokinetics of four long-acting enrofloxacin injectable formulations was investigated in 36 healthy pigs after intramuscular injection according to the recommended single dose @ 2.5 mg/kg body weight. The drug concentrations in the plasma were computed using high-performance liquid chromatography (HPLC) with fluorescence detection. WinNonLin5.2.1 software was used to analyze the experimental data and compared it under one-way ANOVA using SPSS software with a 95% confidence interval (CI). The main pharmacokinetic parameters, that is, the maximum plasma concentrations (Cmax), the time to maximum concentration (Tmax), area under the time curve concentration (AUCall) and Terminal half-life (T1/2) were 733.84 ± 129.87, 917.00 ± 240.13, 694.84 ± 163.49, 621.98 ± 227.25 ng/ml, 2.19 ± 0.0.66, 1.50 ± 0.37, 2.89 ± 0.24, 0.34 ± 0.13 h, 7754.43 ± 2887.16, 8084.11 ± 1543.98, 7369.42 ± 2334.99, 4194.10 ± 1186.62 ng h/ml, 10.48 ± 2.72, 10.37 ± 2.38, 10.20 ± 2.81, and 10.61 ± 0.86 h for 10% enrofloxacin (Alkali), 20% enrofloxacin (Acidic), Yangkang and control drug Nuokang® respectively. There were significant differences among Cmax, Tmax, and AUCall of three formulations compare with that of the reference formulation. No significant differences were observed among the T1/2 for tested formulations compare with the reference formulation. The pharmacokinetic parameters showed that the tested formulations were somewhat better compared to the reference one. The calculated PK/PD indices were effective for bacteria such as Actinobacillus pleuropneumoniae and Pasteurella multocida with values higher than the cut-off points (Cmax/MIC90≥10–12 and AUC/MIC90 ≥ 125). However, they were not effective against bacteria like Haemophilus parasuis, Streptococcus suis, E. coli, and Bordetella bronchiseptica where lower values were obtained.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chiara Tersigni ◽  
Giulia Boiardi ◽  
Lorenzo Tofani ◽  
Elisabetta Venturini ◽  
Carlotta Montagnani ◽  
...  

Abstract Background Low plasma levels of first-line antitubercular drugs can be counted among the main causes of poor response to antitubercular therapy, and therapeutic drug monitoring has been proposed as a method to promote tailored treatments for both child and adult patients. The main aim of the study was to evaluate serum concentrations of isoniazid (INH) and rifampicin (RIF) and to investigate reasons for sub-therapeutic plasma concentrations in order to fix dosages. Methods Children with TB were prospectively enrolled from January to August 2019. Two venous blood samples were collected (the first at least 15 days after the beginning of antitubercular treatment, and the second between 1 and 8 weeks later). Plasma concentrations were determined by a validated high-performance liquid chromatography method. Results In all, 45 children were included. Seventy blood samples for INH plasma concentration were collected between 120 and 240 min after drug intake. Adjusting for dose (mg/kg/day) and time of INH administration, when considering three different age groups (≤ 2 years, 2–12 years, > 12 years), a statistically significant lower INH plasma concentration was observed in younger children compared to the older age groups in the multivariate analysis (p < 0.001 and p < 0.001). A total of 68 blood samples were evaluated for RIF concentrations. Both for INH and RIF a statistically significant lower plasma concentration was also observed in adolescents (p < 0.001). Fifteen children (15/45, 33%) presented drug concentrations under the referral therapeutic range. Conclusions Based on our findings, monitoring patients’ drug plasma concentrations in children under 2 years of age and in adolescents can make treatment more patient-tailored.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3960-3960
Author(s):  
Anne Calleja ◽  
Sandra De Barros ◽  
Camille Vinson ◽  
Caroline Protin ◽  
Lucie Oberic ◽  
...  

Abstract Introduction: Therapeutic drug monitoring (TDM) entails the measurement of drug concentrations and the individualization of drug dosages or schedules to maximize therapeutic effects and minimize toxicity. Ibrutinib (IBR), the first-in-class inhibitor of BTK (Bruton tyrosine kinase) is approved for the therapy of relapsed/refractory chronic lymphocytic leukemia (R/R CLL), mantle cell lymphoma (MCL) and Waldenström's disease (WM), at the dose of 420-560mg/d. Drug-drug interactions (DDI), older age, liver diseases have been reported to impact PK parameters of ibrutinib, but dosing is not yet part of clinical practice, despite TDM of imatinib and other kinase inhibitors is routinely used in chronic myeloid leukemia. In this study, we sought to determine whether TDM of ibrutinib should be proposed for patients, in a preliminary cohort of 73 patients included in the PK-e3i trial (NCT02824159). Methods: Serial plasma PK samples were collected at steady-state after one month of therapy in 73 patients: before intake (residual concentration), and then at time 0.5-1-2-4-6h. Key PK parameters for ibrutinib and its metabolite DHD-ibrutinib were calculated: Cmax, Cmin, tmax,AUC24h. Analysis of DDI was made by an oncology pharmacist in 49/73 patients. Treatment-related adverse events were monitored by phonecalls given by an oncology nurse (AMA procedure) and during consultations with hematologist (at least twice a month the first 6 months, then monthly until 12 months, then every 3 months), and severity graded according CTCAE version 4 scale. Efficacy of therapy in CLL patients was assessed with an "effect marker" to demonstrate biological efficacy, the redistribution hyperlymphocytosis seen in 70% of patients the first month of therapy. Results: we reported very similar PK results for ibrutinib as compared to pivotal phase 1 trials in CLL and other B-cell lymphoid malignancies (Advani RH, J Clin Oncol 2013, Byrd JC, New Engl J Med 2013). Mean peak plasma concentrations were observed 1-2h after dosing, Cmax and AUC results showing an important inter-patient heterogeneity. Median Cmax was 150ng/ml (8.2-596ng/ml), and median AUC24h was 412.4 ng h/mL ((32.2-2906 ng h/mL). According to published phase I trials, complete or near complete BTK occupancy was observed in patients with AUCs exceeding 160 ng h/mL, suggesting ibrutinib dose might have been supramaximal in 67 of our patients. Adverse events the first 3 months were seen in 96% (grade 1), 63% (grade 2), 25% (grade 3) and 6.5% (grade 4), respectively. We plotted AUC results for the total cohort of 73 patients (Figure 1), and for 49 patients with adverse events monitoring available at 3 months (9/49 needed drug dose reduction due to toxicity) (Figure 2), both emphasizing the absence of correlations between AUC levels and toxicities. We next splited up toxicities into 10 sub-groups (bleeding, cardiac, liver, muscle, joint, skin, infection, gastro-intestinal, hematologic, neurologic disorders). Again, we could not identify a specific organ toxicity associated with a significant increase of Cmax or AUC24h, nor we could identify a specific DDI signature explaining side effects in our patents (data not shown: 13/49 had CYP3A4 inhibitors, 25/49 had pgp inhibitors). In 45 CLL patients with PK parameters and lymphocyte counts available after one month of therapy, we made the intriguing observation that lower Cmax correlated with the lack of observable, transient hyperlymphocytosis (a class-effect of ibrutinib, correlating with PFS in the Resonate trial) (Figure 3). Altogether, our data did not find any positive correlation between high ibrutinib exposure and efficacy or safety profile. Conclusions: our preliminary results suggested that higher Cmax and AUC24h did not correlate neither to efficacy nor to classical toxicities reported with ibrutinib intake. On one hand, we think that dosing intra-cellular concentrations could be more reliable than in plasma. On the other hand, we could consider TDM of ibrutinib in the context of a clinical trial reducing the doses of drug over time, to limit clinical and financial toxicity of this highly efficient drug. Disclosures No relevant conflicts of interest to declare.


Cancers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 6281
Author(s):  
Anna Mc Laughlin ◽  
Eduard Schmulenson ◽  
Olga Teplytska ◽  
Sebastian Zimmermann ◽  
Patrick Opitz ◽  
...  

Exposure-efficacy and/or exposure-toxicity relationships have been identified for up to 80% of oral anticancer drugs (OADs). Usually, OADs are administered at fixed doses despite their high interindividual pharmacokinetic variability resulting in large differences in drug exposure. Consequently, a substantial proportion of patients receive a suboptimal dose. Therapeutic Drug Monitoring (TDM), i.e., dosing based on measured drug concentrations, may be used to improve treatment outcomes. The prospective, multicenter, non-interventional ON-TARGET study (DRKS00025325) aims to investigate the potential of routine TDM to reduce adverse drug reactions in renal cell carcinoma patients receiving axitinib or cabozantinib. Furthermore, the feasibility of using volumetric absorptive microsampling (VAMS), a minimally invasive and easy to handle blood sampling technique, for sample collection is examined. During routine visits, blood samples are collected and sent to bioanalytical laboratories. Venous and VAMS blood samples are collected in the first study phase to facilitate home-based capillary blood sampling in the second study phase. Within one week, the drug plasma concentrations are measured, interpreted, and reported back to the physician. Patients report their drug intake and toxicity using PRO-CTCAE-based questionnaires in dedicated diaries. Ultimately, the ON-TARGET study aims to develop a nationwide infrastructure for TDM for oral anticancer drugs.


2020 ◽  
Vol 77 (24) ◽  
pp. 2074-2080
Author(s):  
Amy Legg ◽  
Melanie Halford ◽  
Kate McCarthy

Abstract Purpose Traditionally meropenem has been considered too unstable in solution for continuous infusion. However, in the era of increasing antimicrobial resistance, use of meropenem is becoming more frequently required, and the ability to facilitate its administration via community-based programs would be beneficial. There are some reassuring data about meropenem stability in solution, but data about actual drug exposure in patients and subsequent clinical outcomes are lacking. Summary Here we present a case series of 4 patients at a single tertiary center who received meropenem via continuous infusion coordinated through an outpatient parenteral antimicrobial treatment (OPAT) program. We provide plasma drug concentrations achieved and report on the patients’ clinical progress. All patients achieved drug concentrations of at least 2 times the minimum inhibitory concentration (MIC) while receiving meropenem via continuous infusion and had resolution of their infectious complications. No adverse effects of meropenem continuous infusion were noted. Conclusion Meropenem continuous infusion along with therapeutic drug monitoring was used successfully in a community-based program. Due to interpatient pharmacokinetic variability, we consider meropenem concentration monitoring compulsory during continuous-infusion meropenem therapy.


Author(s):  
Heleen Aardema ◽  
Wouter Bult ◽  
Kai van Hateren ◽  
Willem Dieperink ◽  
Daan J Touw ◽  
...  

Abstract Background In critical care patients, reaching optimal β-lactam concentrations poses challenges, as infections are caused more often by microorganisms associated with higher MICs, and critically ill patients typically have an unpredictable pharmacokinetic/pharmacodynamic profile. Conventional intermittent dosing frequently yields inadequate drug concentrations, while continuous dosing might result in better target attainment. Few studies address cefotaxime concentrations in this population. Objectives To assess total and unbound serum levels of cefotaxime and an active metabolite, desacetylcefotaxime, in critically ill patients treated with either continuously or intermittently dosed cefotaxime. Methods Adult critical care patients with indication for treatment with cefotaxime were randomized to treatment with either intermittent dosing (1 g every 6 h) or continuous dosing (4 g/24 h, after a loading dose of 1 g). We defined a preset target of reaching and maintaining a total cefotaxime concentration of 4 mg/L from 1 h after start of treatment. CCMO trial registration number NL50809.042.14, Clinicaltrials.gov NCT02560207. Results Twenty-nine and 30 patients, respectively, were included in the continuous dosing group and the intermittent dosing group. A total of 642 samples were available for analysis. In the continuous dosing arm, 89.3% met our preset target, compared with 50% in the intermittent dosing arm. Patients not reaching this target had a significantly higher creatinine clearance on the day of admission. Conclusions These results support the application of a continuous dosing strategy of β-lactams in critical care patients and the practice of therapeutic drug monitoring in a subset of patients with higher renal clearance and need for prolonged treatment for further optimization, where using total cefotaxime concentrations should suffice.


2017 ◽  
Vol 117 (12) ◽  
pp. 2369-2375 ◽  
Author(s):  
Sven Poli ◽  
Florian Härtig ◽  
Charlotte Spencer ◽  
Matthias Ebner ◽  
Ingvild Birschmann ◽  
...  

Background Direct oral anticoagulants (DOACs) are increasingly replacing vitamin K antagonists (VKA) for clinical indications requiring long-term oral anticoagulation. In contrast to VKA, treatment with DOAC including dabigatran—the only direct thrombin inhibitor amongst them—does not require therapeutic drug monitoring. However, in case of treatment complications (e.g., major haemorrhage) and conditions requiring urgent surgery or thrombolytic therapy, information about actual DOAC plasma levels is needed to guide treatment decisions. Due to short reagent stability, limited accuracy at low dabigatran levels and high heparin sensitivity, the applicability of the widely used Hemoclot thrombin inhibitor (HTI) coagulation assay is limited in the emergency setting. Methods Dabigatran concentrations of 288 citrated plasma samples taken from 48 dabigatran-treated patients with drug concentrations of up to 300 ng/mL were measured with the chromogenic anti-IIa Biophen direct thrombin inhibitor (BDTI) assay and results compared with HTI using ultra performance liquid chromatography—tandem mass spectrometry as the reference method for measuring dabigatran plasma concentrations. Results BDTI results showed a very strong correlation with dabigatran concentrations (r = 0.965, p < 0.0001) as well as a low intra- and inter-assay variation of <5%. Compared with HTI, BDTI provides an improved on-board reagent stability of 72 hours, rapid turnaround times comparable to routine coagulation assays, high accuracy at low drug levels and reduced heparin sensitivity. Conclusion The BDTI is an ideal coagulation assay for the around-the-clock determination of dabigatran plasma levels in clinical routine including emergency situations.


2019 ◽  
Vol 9 (6) ◽  
pp. 404-407 ◽  
Author(s):  
Rebecca Tourtellotte ◽  
Robert Schmidt

Abstract Limited evidence exists for the use of psychiatric medications in patients with end-stage renal disease on hemodialysis. Many psychotropic medications are not well-studied in this population, and optimal dosing of these medications is not well-established. Therapeutic drug monitoring is a useful tool in assessing the safety and efficacy of psychotropic medications; however, the use is unclear with long-acting injectable antipsychotics. We present a case of a 73-year-old male initiated on hemodialysis while on risperidone microspheres long-acting injection (RMLAI). Risperidone and 9-hydroxyrisperidone plasma concentrations obtained from this patient were relatively similar before and after initiation of hemodialysis, therefore it appears hemodialysis does not significantly influence clearance of RMLAI. Plasma concentrations in this patient were higher than those reported in the literature for equivalent doses, which may indicate accumulation of the medication secondary to renal impairment.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
M. Krivosova ◽  
M. Kertys ◽  
M. Grendar ◽  
I. Ondrejka ◽  
I. Hrtanek ◽  
...  

AbstractDepression is a common mental disorder affecting more than 264 million people in the world and 5.1% of the Slovak population. Although various antidepressant approaches have been used; still, about 40% of patients do not respond to a first-choice drug administration and one third of patients do not achieve total remission. Therapeutic drug monitoring (TDM) is a method used for quantification and interpreting the drug concentrations in plasma in order to optimize the pharmacotherapy. The aim of this study was to measure the plasma concentrations of venlafaxine, the fourth most prescribed antidepressant in Slovakia, as well as its active metabolite and interpret them with the relevant patients’ characteristics.The study was of retrospective nature and 28 adult patients in total were included. The concentrations of venlafaxine and its active metabolite O-desmethylvenlafaxine (ODV) in plasma were quantified using the validated UHPLC-MS/MS method. The effects of potential influencing factors were evaluated by a multivariate linear regression model.Only 39% of patients reached the venlafaxine active moiety concentrations within the recommended therapeutic range. Plasma concentrations were dependent on age, gender, and duration of the therapy. Venlafaxine metabolism expressed as a metabolite-to-parent concentrations ratio was influenced by a combination of age, gender, and body mass index (BMI). We did not observe any significant difference in plasma concentrations between the patients with a single and recurrent diagnosis of depression. Combining variables made an additive effect on plasma concentrations, for example, active moiety plasma concentrations were higher in older women. In contrast, drug metabolism was higher in older men and men with lower BMI. TDM of venlafaxine is recommended in clinical practice, especially in the elderly when beginning the pharmacotherapy.


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