The disposition of many drugs is affected by transporters and thus alterations in transporter activity may affect drug exposure, efficacy and safety. Transporter activity may be affected by many factors, including drugs or food components. In addition, genetic variation in transporter genes may result in interindividual variability in transport. We use cell and membrane vesicle-based methods to study transport and predict drug-drug, food-drug and gene-drug interactions in vitro. Further, we aim to identify transporters involved in drug and metabolite disposition to understand sources of individual variability. By integrating in vitro findings into computational models (e.g., physiologically-based pharmacokinetic models), we aim to translate findings to clinical scenarios.
Sjöstedt N, Amaeze OU, van den Heuvel JJ, Stage TB, Koenderink JB, Isoherranen N, Kidron H, Järvinen E. Dicloxacillin and Flucloxacillin Inhibit Hepatic Uptake Transporters - In Vitro Investigations and Physiologically Based Pharmacokinetic Modeling. Clin Transl Sci. 2026 Feb;19(2):e70487.
Suominen L, Stenberg E, Sjöstedt N, Kidron H. Food Additives Inhibit Intestinal Drug Transporters but Have Limited Effect on In Vitro Drug Permeability. Mol Pharm. 2025 Sep 1;22(9):5627-5637. doi:
The gut microbiota has a complex role in human health and disease. It can also affect drug pharmacokinetics, for example, via reactivation of drug metabolites in the intestine or by altering the expression of transporters or metabolic enzymes. We study how variability in gut microbiota may translate to individual differences in drug glucuronide reactivation and intestinal drug absorption.
Uoti A, Neulasalmi O, Hiippala K, Oksanen T, Arkkila P, Puustinen L, Satokari R, Sjöstedt N. Characterization of fecal deglucuronidation activity in healthy subjects and in patients treated with fecal microbiota transplantation. Drug Metab Dispos. 2025 Nov 20;53(12):100205.
Uoti A, Kurkela M, Niemi M, Oksanen T, Oswald S, Puustinen L, Kidron H, Sjöstedt N. Efflux and uptake transport and gut microbial reactivation of raloxifene glucuronides. Basic Clin Pharmacol Toxicol. 2025 Jan;136(1):e14107.
Intracellular transporters may affect how drugs distribute and reach their targets within the cell, and they might be utilized for improving intracellular drug delivery. We are focusing on lysosomes, which have lately been found to play a role in many key cellular processes. We study the expression and function of transporters in the lysosomal membranes to identify the transporters that affect the accumulation and release of drugs from the lysosomes.