The dolutegravir/valproic acid drug–drug interaction is primarily based on protein displacement

2021 ◽  
Author(s):  
P D J Bollen ◽  
H A B Prins ◽  
A Colbers ◽  
K Velthoven-Graafland ◽  
B J A Rijnders ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Drug Interaction ◽  
Controlled Trial ◽  
Underlying Mechanism ◽  
Hiv Rna ◽  
Parallel Increase ◽  
Drug Drug Interaction ◽  
To Receive ◽  
Protein Displacement

Abstract Objectives The dolutegravir/valproic acid drug–drug interaction (DDI) is suggested to be caused by protein displacement. Here, we assess the underlying mechanism. Methods Participants in a randomized controlled trial investigating valproic acid as an HIV latency reversing agent were recruited in a predefined pharmacokinetic substudy if they were on once-daily 50 mg dolutegravir-containing combination ART (cART) for >12 months with a plasma HIV-RNA <50 copies/mL (trial registration: ClinicalTrials.gov NCT03525730). Participants were randomized to receive 30 mg/kg/day valproic acid orally (divided into two equal doses) for 14 days or not. Total and unbound dolutegravir concentrations were measured on day 0 (before intake of valproic acid and 6 h after intake of valproic acid) and on days 1, 7, 14 and 42. Intra- and inter-subject dolutegravir concentrations and geometric means (GMs) were evaluated. Results Six of 10 participants on dolutegravir were randomized to receive valproic acid. During 14 days of valproic acid treatment, the GM total dolutegravir concentration decreased sharply from 1.36 mg/L on day 0 to 0.85, 0.31 and 0.20 mg/L on days 0, 1, 7 and 14, respectively, while total dolutegravir concentrations in the controls remained comparable during the same period: 1.27–1.49 mg/L. We observed a parallel increase in unbound dolutegravir fractions ranging from 0.39% to 0.58% during valproic acid administration, compared with 0.25% to 0.28% without valproic acid. Unbound dolutegravir concentrations were above the established in vitro EC90 value for unbound dolutegravir in 85% of the tested samples. Conclusions This study confirms protein displacement as the main mechanism for this DDI, although additional mechanisms might be involved too. If dolutegravir is taken with food, this DDI is probably not clinically relevant.

scholarly journals SYNERGISTIC DRUG-DRUG INTERACTION;

2017 ◽  
Vol 24 (08) ◽  
pp. 1206-1210
Author(s):  
Aroosa Ishtiaq Butt ◽  
Bushra Tayyaba Khan ◽  
Zunera Hakim ◽  
Qamar-uz Zaman Khan
Keyword(s):  
Drug Interaction ◽  
Controlled Trial ◽  
Maximum Effect ◽  
Prokinetic Drug ◽  
Drug Drug Interaction ◽  
Group 2 ◽  
The Individual ◽  
Data Acquisition Unit ◽  
Randomised Controlled

Introduction: Ranitidine is known to us all as an anti-ulcer drug which acts byblocking H2 receptors in the stomach parietal cells. However its role in this category has beenunderstated. We studied its prokinetic effect on isolated duodenum of rabbits and its synergisticinteraction with Levosulpiride. The purpose of the study was to see if the two drugs do have aprokinetic effect and whether the combined effect is greater than the individual drugs. StudyDesign: Laboratory based Randomised controlled trial. Period: November 2014 to November2015. Setting: The study was carried out in the multidisciplinary laboratory at Army MedicalCollege after approval from Animals ethics committee. Material and methods: Dose responsecurve was constructed using cumulatively increasing concentrations of Ranitidine (Group 1)and Levosulpiride (Group 2). The synergistic prokinetic drug-drug interaction of Ranitidine andLevosulpiride was observed in Group 3 on iWorx Data acquisition unit (PowerLab). Resultsand Conclusion: Ranitidine produced a dose dependent reversible contraction of the isolatedduodenum and the maximum effect was recorded at 35 μg as 0.136 mV. Levosulpiride produceda maximum contraction of 0.088 mV at 70 μg. Ranitidine and levosulpiride curve was shifted tothe left and upwards of levosulpiride alone. The percent responses of levosulpiride alone was90 percent and with ranitidine was 122 percent. Ranitidine and levosulpiride have a synergisticprokinetic interaction in vitro. Conclusion: Ranitidine and levosulpiride have a synergisticprokinetic drug-drug interaction in vitro.

Antiretroviral concentrations in the presence and absence of valproic acid

2020 ◽  
Vol 75 (7) ◽  
pp. 1969-1971
Author(s):  
A Calcagno ◽  
J Cusato ◽  
M Ferrara ◽  
A De Nicolò ◽  
A Lazzaro ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Drug Interaction ◽  
Plasma Concentrations ◽  
Integrase Inhibitor ◽  
Major Effect ◽  
Therapeutic Drug ◽  
Hiv Integrase ◽  
Drug Drug Interaction ◽  
Underlying Mechanisms ◽  
Protein Displacement

Abstract Objectives An unexpected drug–drug interaction has been recently reported between dolutegravir, an HIV integrase inhibitor, and valproic acid. Despite there being several potential underlying mechanisms, plasma protein displacement has been suggested. The aim of this study was to assess plasma concentrations of several antiretrovirals when administered with or without valproic acid. Methods We performed a therapeutic drug monitoring registry analysis and identified patients concomitantly taking antiretrovirals and valproic acid and without clinical affecting conditions or interacting drugs. Results One hundred and thirty-four patients were identified. Median (IQR) age and BMI were 49.7 years (45–56) and 23.4 kg/m2 (20.8–26.3) and 78 were male (58.2%). Despite small groups, we observed no major effect on antiretroviral exposure, even when considering highly protein-bound compounds (such as etravirine), with the exception of dolutegravir trough concentrations [median (IQR) = 132 ng/mL (62–227) in individuals on valproic acid versus 760 ng/mL (333–1407) in those not receiving valproic acid]. Conclusions Valproic acid does not have a major effect on antiretrovirals other than dolutegravir. The mechanism of this unexpected drug–drug interaction may be the combination of protein displacement, reduced absorption and CYP3A4 induction.

Pharmacokinetic Drug-drug Interaction of Antibiotics Used in Sepsis Care in China

2020 ◽  
Vol 21 ◽  
Author(s):  
Xuan Yu ◽  
Zixuan Chu ◽  
Jian Li ◽  
Rongrong He ◽  
Yaya Wang ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Drug Interactions ◽  
Penicillin G ◽  
Literature Mining ◽  
Human Pharmacokinetics ◽  
P450 Enzyme ◽  
Drug Drug Interaction ◽  
Pharmacokinetic Drug ◽  
Sepsis Care

Background: Many antibiotics have a high potential for having an interaction with drugs, as perpetrator and/or victim, in critically ill patients, and particularly in sepsis patients. Methods: The aim of this review is to summarize the pharmacokinetic drug-drug interaction (DDI) of 45 antibiotics commonly used in sepsis care in China. Literature mining was conducted to obtain human pharmacokinetics/dispositions of the antibiotics, their interactions with drug metabolizing enzymes or transporters, and their associated clinical drug interactions. Potential DDI is indicated by a DDI index > 0.1 for inhibition or a treated-cell/untreated-cell ratio of enzyme activity being > 2 for induction. Results: The literature-mined information on human pharmacokinetics of the identified antibiotics and their potential drug interactions is summarized. Conclusion: Antibiotic-perpetrated drug interactions, involving P450 enzyme inhibition, have been reported for four lipophilic antibacterials (ciprofloxacin, erythromycin, trimethoprim, and trimethoprim-sulfamethoxazole) and three lipophilic antifungals (fluconazole, itraconazole, and voriconazole). In addition, seven hydrophilic antibacterials (ceftriaxone, cefamandole, piperacillin, penicillin G, amikacin, metronidazole, and linezolid) inhibit drug transporters in vitro. Despite no reported clinical PK drug interactions with the transporters, caution is advised in the use of these antibacterials. Eight hydrophilic antibacterials (all β-lactams; meropenem, cefotaxime, cefazolin, piperacillin, ticarcillin, penicillin G, ampicillin, and flucloxacillin), are potential victims of drug interactions due to transporter inhibition. Rifampin is reported to perpetrate drug interactions by inducing CYP3A or inhibiting OATP1B; it is also reported to be a victim of drug interactions, due to the dual inhibition of CYP3A4 and OATP1B by indinavir. In addition, three antifungals (caspofungin, itraconazole, and voriconazole) are reported to be victims of drug interactions because of P450 enzyme induction. Reports for other antibiotics acting as victims in drug interactions are scarce.

Pseudo-Parkinson Disease Secondary to Ritonavir–Buspirone Interaction

2003 ◽  
Vol 37 (2) ◽  
pp. 202-205 ◽  
Author(s):  
Patrick G Clay ◽  
Molly M Adams
Keyword(s):  
Drug Interaction ◽  
Inhibitory Effect ◽  
Hiv Positive ◽  
High Dose ◽  
Resting Tremor ◽  
Case Summary ◽  
History Of ◽  
Drug Drug Interaction ◽  
To Receive

OBJECTIVE: To report a case of Parkinson-like symptoms appearing in a patient after introduction of ritonavir to buspirone therapy. CASE SUMMARY: A 54-year-old HIV-positive white man presented to the clinic with a 2-week history of ataxia, shuffling gait, cogwheel rigidity, resting tremor, and sad affect with masked features. This patient had been receiving high-dose buspirone (40 mg every morning and 30 mg every evening) for 2 years prior to the introduction of ritonavir/indinavir combination therapy (400 mg/400 mg twice daily) 6 weeks prior to initiation of the above symptoms. Buspirone was decreased to 15 mg 3 times daily, ritonavir/indinavir was discontinued, and amprenavir 1200 mg twice daily was added. The patient's symptoms began to subside after 1 week, with complete resolution after about 2 weeks. The patient continued to receive buspirone for an additional 12 months without recurrence of symptoms. DISCUSSION: This is the first reported interaction of buspirone and antiretrovirals. Buspirone, extensively metabolized by CYP3A4, was likely at supratherapeutic levels due to the inhibitory effect of ritonavir and, secondarily, indinavir. The Parkinson-like symptoms developed rapidly and severely, impacted this patient's quality of life, and necessitated significant clinic expenditures to identify this drug–drug interaction. CONCLUSIONS: This case demonstrates a severe drug–drug interaction between buspirone and ritonavir and further demonstrates the need for awareness of the metabolic profile for all agents an HIV-infected patient is receiving.

scholarly journals In vitro study on the effect of cornin on the activity of cytochrome P450 enzymes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qun Zhang ◽  
Zengqiang Qu ◽  
Yanqing Zhou ◽  
Jin Zhou ◽  
Junwei Yang ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Drug Interaction ◽  
Liver Microsomes ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Cytochrome P450 Enzymes ◽  
Drug Drug Interaction ◽  
Dose Dependent

Abstract Background Cornin is a commonly used herb in cardiology for its cardioprotective effect. The effect of herbs on the activity of cytochrome P450 enzymes (CYP450s) can induce adverse drug-drug interaction even treatment failure. Therefore, it is necessary to investigate the effect of cornin on the activity of CYP450s, which can provide more guidance for the clinical application of cornin. Methods Cornin (100 μM) was incubated with eight isoforms of CYP450s, including CYP1A2, 2A6, 3A4, 2C8, 2C9, 2C19, 2D6, and 2E1, in pooled human liver microsomes. The inhibition model and corresponding parameters were also investigated. Results Cornin exerted significant inhibitory effect on the activity of CYP3A4, 2C9, and 2E1 in a dose-dependent manner with the IC50 values of 9.20, 22.91, and 14.28 μM, respectively (p < 0.05). Cornin inhibited the activity of CYP3A4 non-competitively with the Ki value of 4.69 μM, while the inhibition of CYP2C9 and 2E1 by cornin was competitive with the Ki value of 11.31 and 6.54 μM, respectively. Additionally, the inhibition of CYP3A4 by cornin was found to be time-dependent with the KI/Kinact value of 6.40/0.055 min− 1·μM− 1. Conclusions The inhibitory effect of cornin on the activity of CYP3A4, 2C9, and 2E1 indicated the potential drug-drug interaction between cornin and drugs metabolized by these CYP450s, which needs further investigation and validation.

In vitro and in vivo Drug-Drug Interaction of Losartan and Glimepiride in Rats and Its Possible Mechanism

Pharmacology ◽  
2015 ◽  
Vol 95 (3-4) ◽  
pp. 133-138 ◽  
Author(s):  
Sai-Zhen Chen ◽  
Pei-Pei Pan ◽  
Shuang-Hu Wang ◽  
Jun Luo ◽  
Guo-Xin Hu ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Drug Drug Interaction
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