Aims: To investigate the effect of tetracycline co-administration on the pharmacokinetics of halofantrine in healthy subjects.
Methods: Eight healthy males were each given 500 mg single oral doses of halofantrine alone, or with tetracycline (500 mg 12 hourly for 7 days), in a crossover fashion. Blood samples collected at predetermined intervals were analyzed for halofantrine and its major metabolite, desbutylhalofantrine (HFM), using a validated HPLC method.
Results: Co-administration of tetracycline and halofantrine resulted in a significant increase (P < 0.05) in the maximum plasma concentration (C(max)), total area under the concentration-time curve (AUC), and terminal elimination half-life (t(1/2,z)), compared with halofantrine alone. (C(max) 0.43 +/- 0.14 vs 1.06 +/- 0.44 microg ml(-1) (95% CI on the difference 0.30, 0.95); AUC 32.0 +/- 13.6 vs 63.7 +/- 20.1 microg ml(-1) h (95% CI 14.2, 49.1); t(1/2,z:) 90.8 +/- 17.9 vs 157.4 +/- 57.4 h (95% CI 21.7, 111.5)). Similarly, tetracycline caused a significant increase (P < 0.05) in the AUC and C(max) of HFM.
Conclusions: Tetracycline co-administration significantly increases the plasma concentrations of halofantrine and its major metabolite.
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http://dx.doi.org/10.1111/j.1365-2125.2004.02087.x | DOI Listing |
Mol Pharm
May 2024
Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
In recent years, the drainage of fluids, immune cells, antigens, fluorescent tracers, and other solutes from the brain has been demonstrated to occur along lymphatic outflow pathways to the deep cervical lymph nodes in the neck. To the best of our knowledge, no studies have evaluated the lymphatic transport of therapeutics from the brain. The objective of this study was to determine the lymphatic transport of model therapeutics of different molecular weights and lipophilicity from the brain using cervical lymph cannulation and ligation models in rats.
View Article and Find Full Text PDFAfr Health Sci
March 2023
Department of Pharmaceutical Chemistry, University of Ibadan, Ibadan, Nigeria.
Background: There is rekindled interest in the cardiotoxicity of antimalarial medicines. Halofantrine is associated with QT interval prolongation. Fluconazole and kolanut alter the pharmacokinetics of halofantrine.
View Article and Find Full Text PDFJ Pharm Sci
March 2021
Drug Metabolism and Pharmacokinetics, Genentech Inc, 1 DNA Way, South San Francisco, CA 94080, USA.
Absorption via the intestinal lymphatic system is known to be important for some highly lipophilic compounds, and can be associated with unique pharmacokinetic properties due to evasion of hepatic first-pass metabolism. This work aimed to develop a physiologically-based pharmacokinetic model incorporating the role of lymphatic transport in a physiologically-based, mechanistic oral absorption model, using halofantrine as a model compound. Simcyp V19 was used for model development; oral absorption was characterized using the multi-layer gut wall (M-ADAM) model, and the model was constructed and verified using parameters derived from in vitro experiments and clinical PK data.
View Article and Find Full Text PDFTrials
July 2020
Division of Experimental Medicine & Immunotherapeutics, University of Cambridge, Cambridge, UK.
Objectives: PRIMARY OBJECTIVE: To determine whether chemoprophylaxis with hydroxychloroquine versus placebo increases time to contracting coronavirus disease 2019 (COVID-19) in frontline healthcare workers.
Secondary Objectives: 1) To determine whether chemoprophylaxis with daily versus weekly dosing of hydroxychloroquine increases time to contracting COVID-19 disease in frontline healthcare workers. 2) To compare the number of COVID-19 cases between each trial arm on the basis of positive tests (as per current clinical testing methods and/or serology) 3) To compare the percentage of COVID-19 positive individuals with current testing methods versus serologically-proven COVID-19 in each trial arm 4) To compare COVID-19 disease severity in each trial arm 5) To compare recovery time from COVID-19 infection in each trial arm EXPLORATORY OBJECTIVES: 1) To determine compliance (as measured by trough pharmacokinetic hydroxychloroquine levels) on COVID-19 positive tests 2) To determine if genetic factors determine susceptibility to COVID-19 disease or response to treatment 3) To determine if blood group determines susceptibility to COVID-19 disease 4) To compare serum biomarkers of COVID-19 disease in each arm TRIAL DESIGN: Double-blind, multi-centre, 2-arm (3:3:2 ratio) randomised placebo-controlled trial PARTICIPANTS: National Health Service (NHS) workers who have direct patient contact delivering care to patients with COVID-19.
Mol Pharm
March 2020
Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, Victoria 3052, Australia.
Techniques enabling monitoring of drug solubilization and changes in the solid-state of the drug during the digestion of milk and milk-based formulations are valuable for predicting the effectiveness of such formulations in improving the oral bioavailability of poorly water-soluble drugs. We have recently reported the use of low-frequency Raman scattering spectroscopy (region of analysis <200 cm) as an analytical approach to probe solubilization of drugs during digestion in milk using ferroquine (SSR97193) as the model compound. This study investigates the wider utilization of this technique to probe the solubilization behavior of other poorly water-soluble drugs (halofantrine, lumefantrine, and clofazimine) in not only milk but also infant formula in the absence or presence of bile salts during digestion.
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