BackgroundDifferent patient groups are known to use herbal remedies and conventional drugs concomitantly (co-use). This poses a potential risk of herb-drug interaction through altering the drug’s pharmacokinetics or pharmacodynamics. Little is known about co-use among patients in general practice. The primary aim of this study was to compare patients in general practice that co-use herbal remedies and conventional drugs with those who do not. The secondary aim was to register the herb-drug combinations with potential clinical relevant interactions among the co-users.MethodA questionnaire based cross-sectional study conducted in the autumn 2011 in a general practice office with four general practitioners (GPs) and one intern in Western Norway. Adults >18 years who came for an office visit were invited. The questionnaire asked about demographics, herbal use, conventional drug use and communication about herbal use. Multivariable logistic regression was used to compare co-users to the other patients.ResultsOf the 381 patients who completed the questionnaire, the prevalence of herbal use was 44%, with bilberry (41%), green tea (31%), garlic (27%), Aloe vera (26%) and echinacea (18%) as the most frequently used. Among those using conventional drugs regularly, 108 (45%) co-used herbs. Close to 40% of patients on anticoagulants co-used herbs, with garlic and bilberry as the most frequent herbs. Compared to all other patients, co-users had significantly (p < 0.05) increased odds to be female (adjOR 2.0), age above 70 years (adjOR 3.3), use herbs to treat an illness (adjOR 4.2), use two or more herbs (polyherbacy, adjOR 12.1) and having experienced adverse effects of herbal use (adjOR 37.5). Co-use was also associated with use of analgesics or dermatological drugs (adjOR 5.1 and 7.9 respectively). Three out of four patients did not discuss herbal use with any health care professional.ConclusionA sizable proportion of the GP patients co-used herbs with conventional drugs, also combinations with reported interaction potential or additive effects like anticoagulants and garlic. The low disclosure of herbal use to their GP, polyherbacy and the risk of interactions in vulnerable groups like elderly and chronically ill patients, warrant increased awareness among GPs.

The aim of this study was to evaluate the inhibitory potency (IC 50 values) of ethanol extracts of two commercially available aloe vera juice (AVJ) products, on CYP3A4 and CYP2D6 activities in vitro and to determine if such inhibitions could be mechanism-based. Recombinant human CYP3A4 and CYP2D6 enzymes were used and the activities were expressed by the metabolism of testosterone and dextromethorphan with ketoconazole and quinidine as positive inhibitor controls, respectively. The formed metabolites were quantified by validated HPLC techniques. Time-and NADPH-dependent inhibition assays were performed to evaluate a possible mechanism-based inhibition. One of the AVJ extracts showed about twice the inhibitory potency towards both CYP enzymes over the other with IC 50 values of 8.35AE0.72 and 12.5AE2.1mg/mL for CYP3A4 and CYP2D6, respectively. The AVJ was found to exert both CYP mediated and non-CYP mediated inhibition of both CYP3A4 and CYP2D6. This dual mechanistic inhibition, however, seems to be governed by different mechanisms for CYP3A4 and CYP2D6. Estimated IC 50 inhibition values indicate no major interference of AVJ with drug metabolism in man, but the dual mechanistic inhibition of both enzymes might be of clinical significance.

The aims of this study were to carry out a thorough quality control setup for essential Caco-2 cell characteristics in P-glycoprotein (P-gp) inhibition studies and to explore if Aloe vera juice (AVJ) inhibits the bidirectional transport of the P-gp substrate digoxin (30 nm). Seven AVJ concentrations (0.00001-1.0 mg/mL), anticipated to cover a clinically relevant range, were tested and digoxin apparent permeability coefficients (Papp), net Papp values (Papp(Net)) and net flux values (J(Net)) were calculated. Relevant validation parameters for P-gp inhibition studies in Caco-2 cells are suggested to include, as a minimum, an assay linearity test with and without a known P-gp inhibitor, cell cytotoxicity testing (MTT-test) for substrates and inhibitors, and cell integrity testing by TEER and mannitol transport measurements. The question is also raised whether a minimum effect of a reference P-gp inhibitor as verapamil should be demanded. Cell cytotoxicity was seen for digoxin at concentrations >or=3 microM and for AVJ at 10 mg/mL. AVJ did not inhibit the P-gp transport of digoxin in any of the concentrations tested. This indicates that AVJ is no inhibitor of the P-gp mediated transport of digoxin in vitro if AVJ is present in clinically relevant concentrations.

er lege i spesialisering i geriatri ved Mo aksklinikken, Geriatrisk seksjon, Stavanger universitetssjukehus og ph.d.-kandidat ved Klinisk Institu 1, Universitetet i Bergen og Regionalt kompetansesenter for eldremedisin og samhandling (SESAM), Stavanger universitetssjukehus. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Hogne Sønnesyn er ph.d., overlege ved Geriatrisk seksjon, Stavanger universitetssjukehus og seniorforsker ved Regionalt kompetansesenter for eldremedisin og samhandling (SESAM), Stavanger universitetssjukehus. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Anne Katrine Bergland er ph.d., spesialist i geriatri og i aku -og mo aksmedisin, seksjonsoverlege ved Observasjons-og behandlingsavdelingen, Stavanger universitetssjukehus og seniorforsker ved Regionalt kompetansesenter for eldremedisin og samhandling (SESAM), Stavanger universitetssjukehus. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Dag Årsland er spesialist i psykiatri, overlege og forskningsleder ved Regionalt kompetansesenter for eldremedisin og samhandling (SESAM), Stavanger universitetssjukehus samt professor og avdelingsleder ved Alderspsykiatrisk avdeling, Institute of Psychiatry, Psychology and Neuroscience ved King's College London. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Ane Djuv er ph.d., overlege i ortopedisk kirurgi, fagleder ved Ortopedisk osteoporosepoliklinikk, leder av Frakturregisteret i Helse Stavanger, leder av Register for beinbrudd og osteoporoseutredning (BeinOP). Hun er førsteamanuensis ved Klinisk institu 1, Universitetet i Bergen og forsker ved Regionalt kompetansesenter for eldremedisin og samhandling, Stavanger universitetssjukehus. Forfa eren har fylt ut ICMJE-skjemaet og oppgir følgende interessekonflikter: Hun har mo a rådgivningshonorar fra UCB. Audun Osland Vik-Mo er spesialist i psykiatri, avdelingsoverlege ved Alderspsykiatrisk avdeling, Stavanger universitetssjukehus, førsteamanuensis og fagleiar for Vestlandslegen, Universitetet i Bergen. Forfa eren har fylt ut ICMJE-skjemaet og oppgir ingen interessekonflikter. Vi må bry oss om delirium | Tidsskrift for Den norske legeforening