scholarly journals Pharmacokinetic interactions: from mechanisms to clinical relevance

2014 ◽  
Vol 1 (2) ◽  
pp. 85-95
Author(s):  
Amel Ahmane ◽  
◽  
Hocine Gacem ◽  
Karim Boulesbiaat ◽  
Meriem Boullelli
Keyword(s):  
Protein Binding ◽  
Drug Interactions ◽  
Tissue Distribution ◽  
Nuclear Receptors ◽  
Clinical Relevance ◽  
Pharmacokinetic Interaction ◽  
Current Data ◽  
Pharmacological Properties ◽  
Drug Concentrations ◽  
Pharmacokinetic Properties

Among the various types of known drug interactions, those involving pharmacokinetic processes are more complex and dangerous. From digestive pH changes to plasma protein binding and induction or inhibition phenomena; current data used to define, with precision, the sites of interaction. The enzymes involved in metabolism, the transporters involved in tissue distribution and excretion of drugs, and nuclear receptors that regulate the expression of these enzymes and transporters are keys determinants that should be defined for each drug. The clinical relevance of a pharmacokinetic interaction is related to the magnitude of changes in drug concentrations and pharmacological properties of these. Good knowledge of the pharmacokinetic properties of drugs and the mechanisms involved in the genesis of these interactions is, then, needed to prevent and avoid theme.

Pharmacokinetic Properties of New Antiepileptic Drugs

2005 ◽  
Vol 18 (6) ◽  
pp. 444-460 ◽  
Author(s):  
Michele Y. Splinter
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Interactions ◽  
Antiepileptic Drugs ◽  
Drug Monitoring ◽  
The United States ◽  
Therapeutic Drug ◽  
Kinetic Properties ◽  
New Antiepileptic Drugs ◽  
Drug Concentrations ◽  
Pharmacokinetic Properties

Eight new antiepileptic drugs (AEDs) have been approved for use within the United States within the past decade. They are felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, and zonisamide. These afford clinicians with more options to increase efficacy and tolerability in the treatment of patients with epilepsy. Pharmacokinetic properties and drug interactions with other AEDs and other medications taken for comorbidities are individually discussed for each of these new agents. Drug concentrations are not routinely monitored for these newer agents, and there have been few studies designed to investigate their concentration-effect relationships. For most of these medications, the concentrations observed in responders and nonresponders overlap considerably and levels associated with efficacy are often associated with adverse events, complicating the definition of target ranges. Also, epilepsy manifests itself sporadically causing difficulty in clinically monitoring efficacy of medications. Therapeutic drug monitoring provides for the individualization of treatment for these agents, which is important because they demonstrate significant variability in inter- and intraindividual pharmaco-kinetic properties. Therapeutic drug monitoring also allows for identification of noncompliance, drug interactions, and toxicity. Current knowledge of the relationships between efficacy, toxicity, and drug concentrations is discussed.

Pharmacokinetics of hydroxychloroquine and chloroquine during treatment of rheumatic diseases

Lupus ◽  
1996 ◽  
Vol 5 (1_suppl) ◽  
pp. 11-15 ◽  
Author(s):  
Daniel E Furst
Keyword(s):  
Protein Binding ◽  
Mononuclear Cells ◽  
Morning Stiffness ◽  
Pharmacokinetic Interaction ◽  
Great Variability ◽  
Severe Malnutrition ◽  
Blood Clearance ◽  
Blood Concentrations ◽  
Drug Concentrations ◽  
Differential Binding

Hydroxychloroquine (HCQ) and chloroquine (CQ) are well absorbed (0.7-0.8 bioavailability) when given orally. Severe malnutrition (such as kwashiorkor) effects absorption but diahrrea does not. Both HCQ and CQ have prolonged half-lives, between 40 and 50 days, and low blood clearance (e.g. hydroxychloroquine's blood clearance is 96 ml/min). There is great variability of blood concentrations with an eleven-fold range of drug concentrations found after similar doses in RA patients. Protein binding ranges between 30 and 40% with binding to both albumin and alpha1 glycoprotein. There is differential binding and metabolism of the (R) and (S) stereoisomers. Both drugs bind strongly to pigmented tissues but also bind to mononuclear cells, muscles, etc. There is stereo-selective excretion of both drugs and 40-50% of the drug is excreted renally. Between 21 and 47% is excreted unchanged. There is a suggestion of concentration response and concentration toxicity relationships with decreased morning stiffness as HCQ concentrations increase and increased EKG abnormalities as CQ concentrations become higher, but further testing is required. Pharmacokinetic interaction studies are limited. Potentially important kinetic interactions have been documented for d-penicillamine and cimetidine but have not been found for aspirin, ranitidine or imipramine.

scholarly journals Pharmacokinetic and safety study of co-administration of albendazole, diethylcarbamazine, Ivermectin and azithromycin for the integrated treatment of Neglected Tropical Diseases

2020 ◽  
Author(s):  
Lucy N John ◽  
Catherine Bjerum ◽  
Pere Millat Martinez ◽  
Rhoda Likia ◽  
Linda Silus ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Large Scale ◽  
Neglected Tropical Diseases ◽  
Pharmacokinetic Interaction ◽  
Integrated Treatment ◽  
Secondary Outcome ◽  
Pharmacokinetic Data ◽  
Tropical Diseases ◽  
Open Label ◽  
Significant Difference

Abstract Background Pharmacokinetic data are a pre-requisite to integrated implementation of large-scale mass drug administration (MDA) for neglected tropical diseases (NTDs). We investigated the safety and drug interactions of a combination of azithromycin (AZI) targeting yaws and trachoma, with the newly approved ivermectin, albendazole, diethylcarbamazine (IDA) regime for Lymphatic Filariasis. Methodology An open-label, randomized, 3-arm pharmacokinetic interaction study in adult volunteers was carried out in Lihir Island, Papua New Guinea. Healthy adult participants were recruited and randomized to (I) IDA alone, (II) IDA combined with AZI, (III) AZI alone. The primary outcome was lack of a clinically relevant drug interaction. The secondary outcome was the overall difference in the proportion of AEs between treatment arms. Results Thirty-seven participants, eighteen men and nineteen women, were randomized and completed the study. There were no significant drug-drug interactions between the study arms. The GMR of Cmax, AUC0–t, and AUC0–∞ for IVM, DEC, ALB-SOX, and AZI were within the range of 80–125% (GMR for AUC0–∞ for IVM, 87.9; DEC, 92.9; ALB-SOX, 100.0; and AZI, 100.1). There was no significant difference in the frequency of AEs across study arms (AZI and IDA alone arms 9/12 (75%), co-administration arm 12/13 (92%); p = 0.44). All AEs were grade 1 and self-limiting. Conclusions Co-administration of AZI with IDA did not show evidence of significant drug-interactions. There were no serious AEs in any of the study arms. Our data support further evaluation of the safety of integrated MDA for NTDs. Clinical Trials Registration. NCT03664063

Pharmacological profile of antihistamines: focus on unwanted drug interactions

2021 ◽  
Vol 17 (4) ◽  
pp. 46-56
Author(s):  
Alexander S. Dukhanin
Keyword(s):  
Drug Interactions ◽  
Second Generation ◽  
The Body ◽  
Pharmacological Profile ◽  
Luminal Membrane ◽  
Pharmacokinetic Properties ◽  
System 2 ◽  
Specific Affinity ◽  
Histamine H1 Receptors

Differences between individual antihistamines are determined by such pharmacokinetic properties as the rate and completeness of absorption, half-life, the participation of hepatic and renal mechanisms of elimination from the body. Pharmacodynamic features of the antihistamine include selectivity and affinity for histamine H1-receptors and the presence of central effects. The mechanisms of the development of unwanted drug interactions with second-generation antihistamines are analyzed in detail. Three levels of interaction have been identified: 1) hepatic enzymes of the P450 system; 2) membrane carriers of organic anions (OATP) transport proteins on the sinusoidal membrane of hepatocytes and the luminal membrane of the epithelium of the proximal nephron tubule; 3) P-glycoprotein (Pgp, ABCB1-protein) of epithelial cells of the small intestine the area of absorption of oral forms of antihistamines, the epithelium of the proximal tubule and the BBB (blood-brain barrier). The emphasis is made on the description of the dependence of the pharmacological profile of antihistamines on its chemical structure. The elasticity of the bilastine molecule, the ability to induce a change in conformation underlies the high complementarity of bilastine to the recognition site of the H1-receptor which is a high affinity. Experimental evaluation confirms this conclusion: the dissociation constant (Dс) of the bilastin-receptor complex is in the nM concentration range. The bilastine molecule, as a representative of antihistamines with zwitterionic properties, carries both a positive and a negative charge at a physiological pH, making it difficult for its penetration into the brain. The peculiarities of the chemical nature of the bilastine molecule are reflected in the specific pharmacological profile of AGP. In vitro studies have shown a high specific affinity of bilastine for H1-receptors with a very low affinity for other histamine receptors (H2, H3, H4), serotonin, bradykinin, muscarinic and adrenergic receptors). According to this indicator, bilastine is 3 times higher than cetirizine and 5 times higher than fexofenadine. Bilastine is practically not metabolized in the body and is excreted mainly unchanged, and also does not have a cardiotoxic effect. Bilastine is well tolerated; as a therapeutic dose it has a less pronounced sedative potential compared to other second-generation antihistamines.

scholarly journals Expression Profiling of Nuclear Receptors in the NCI60 Cancer Cell Panel Reveals Receptor-Drug and Receptor-Gene Interactions

2010 ◽  
Vol 24 (6) ◽  
pp. 1287-1296 ◽  
Author(s):  
Susan Holbeck ◽  
Jianjun Chang ◽  
Anne M. Best ◽  
Angie L. Bookout ◽  
David J. Mangelsdorf ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Cell Lines ◽  
Nuclear Receptors ◽  
Cancer Cell ◽  
Expression Profiling ◽  
Expression Profiles ◽  
Receptor Gene ◽  
Receptor Expression ◽  
Cancer Drug ◽  
Mrna Levels

Abstract We profiled the expression of the 48 human nuclear receptors (NRs) by quantitative RT-PCR in 51 human cancer cell lines of the NCI60 collection derived from nine different tissues. NR mRNA expression accurately classified melanoma, colon, and renal cancers, whereas lung, breast, prostate, central nervous system, and leukemia cell lines exhibited heterogeneous receptor expression. Importantly, receptor mRNA levels faithfully predicted the growth-inhibitory qualities of receptor ligands in nonendocrine tumors. Correlation analysis using NR expression profiles and drug response information across the cell line panel uncovered a number of new potential receptor-drug interactions, suggesting that in these cases, individual receptor levels may predict response to chemotherapeutic interventions. Similarly, by cross-comparing receptor levels within our expression dataset and relating these profiles to existing microarray gene expression data, we defined interactions among receptors and between receptors and other genes that can now be mechanistically queried. This work supports the strategy of using NR expression profiling to classify various types of cancer, define NR-drug interactions and receptor-gene networks, predict cancer-drug sensitivity, and identify druggable targets that may be pharmacologically manipulated for potential therapeutic intervention.

β-Adrenergic receptors, voltage-operated Ca 2+-channels, nuclear triiodothyronine receptors and triiodothyronine concentration in pig myocardium after long-term low-dose amiodarone treatment

1993 ◽  
Vol 129 (4) ◽  
pp. 337-347 ◽  
Author(s):  
Liv Bjørn-Hansen Gøtzsche
Keyword(s):  
Cardiac Surgery ◽  
Nuclear Receptors ◽  
Adrenergic Receptors ◽  
Low Dose ◽  
Binding Capacity ◽  
Drug Concentrations ◽  
Cardiac Strain ◽  
Amiodarone Treatment ◽  
Β Adrenergic Receptors

Similar features during chronic amiodarone treatment and hypothyroidism suggest that amiodarone induces a state of "triiodothyronine (T3)-resistance" or "cardiac hypothyroidism", which may predispose the heart to pump failure under conditions with severe strain, such as recovery after cardiac surgery. Disagreements exist as to how amiodarone, and possibly its main metabolite desethylamiodarone, act upon the various receptor systems in the heart. The aim of the present study was to elucidate whether chronic amiodarone treatment leads to a functional reduction in the number of myocardial nuclear T3 receptors, the myocardial tissue T3 concentration and the number of β-receptors and voltage-operated Ca2+-channels. Finally, special attention was drawn to any changes that could contribute to explain previous reports on reduced haemodynamic reserve in animals exposed to severe cardiac strain, such as cardiac surgery. Pigs (72±2 kg) were assigned randomly to amiodarone treatment (20 mg·kg−1·day−1 for 30±1 days, N = 8); controls received no medical treatment (N = 6). The left ventricle was evaluated for β-adrenergic receptors, voltage-operated Ca2+-channels, T3 nuclear receptors and tissue T3 concentration. Maximum binding capacity for β-receptors and Ca2+-channels was reduced in amiodarone-treated pigs (by 38%, p<0.05, and by 52%, p<0.01) and correlated with tissue drug concentrations for both receptor types (p<0.05). No changes were observed concerning nuclear T3 receptors. In vitro competition studies revealed that amiodarone, but not desethylamiodarone, possessed binding properties to Ca2+-channels, whereas neither of the compounds bound to β-receptors. Desethylamiodarone, but not amiodarone, competitively inhibited T3 binding to its nuclear receptors. Myocardial T3 was undetectable (<0.05 nmol/kg wet wt) in amiodarone-treated pigs. From our observations we suggest that the active metabolite desethylamiodarone, rather than the parent drug, is mainly responsible for the observed local hypothyroid-like effects during amiodarone treatment. The observed changes after treatment with low-dose amiodarone in pigs are likely to have biological implications. Functionally, the changes may imply reduced cardiac reserve during conditions of extraordinary strain.

Interactions between SSRI's and statins: Clinical relevance versus statistical significance

2017 ◽  
Vol 41 (S1) ◽  
pp. S757-S758 ◽  
Author(s):  
S. Petrykiv ◽  
L. De Jonge ◽  
M. Arts
Keyword(s):  
Drug Interactions ◽  
Clinical Relevance ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Absolute Risk ◽  
Statistical Significance ◽  
Developed Countries ◽  
Lipid Lowering ◽  
Supporting Evidence ◽  
Cytochrome P450 Enzyme

IntroductionDepression and hypercholesterolemia are two of the most commonly treated conditions in the developed countries, while the lipid–lowering agents and antidepressants are among the most widely prescribed drugs in the world. There is a common concern that selective serotonin reuptake inhibitors (SSRIs) can trigger statin adverse effects, especially myopathy. However, the supporting evidence originates from studies in-vitro and big epidemiological studies. Recent pharmacokinetic insights indicate that the magnitude of pharmacokinetic interaction between SSRIs and statins is likely to be below the threshold for clinical significance.Objectives and aimsExplorative study on pharmacokinetic effects of SSRIs on statin drugs.MethodsWe performed a detailed literature review through PubMed, EMBASE and Cochran's Library to assess the clinical relevance of combined SSRIs and statin use. To address pharmacokinetic interactions between two drug groups, we focused on:– cytochrome P450 enzyme metabolism of statins;– CYP enzyme inhibition by SSRIs;– SSRIs–statin drug interactions;– non-CYP pharmacokinetic pathways.ResultsWith regard to pharmacokinetic drug interactions and the risk of statin related myopathy, escitalopram, citalopram, and paroxetine are to be safe in co-therapy with all statins. Rosuvastatin and pravastatin are almost certain to be safe in co-therapy with all SSRIs. Fluoxetine and sertraline are also likely to be safe, even when combined with atorvastatin, simvastatin, and lovastatin.ConclusionThough the absolute risk of concomitant use of SSRIs with statins seems to be negligible, even this risk can be minimized by using lower statin doses and monitoring the patient.Disclosure of interestThe authors have not supplied their declaration of competing interest.

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