Understanding the Risk of Drug Interactions Between Ritonavir-Containing COVID-19 Therapies and Small-Molecule Kinase Inhibitors in Patients With Cancer.

PURPOSE: The introduction of COVID-19 therapies containing ritonavir has markedly expanded the scope of use for this medicine. As a strong cytochrome P450 3A4 inhibitor, the use of ritonavir is associated with a high drug interaction risk. There are currently no data to inform clinician regarding the likely magnitude and duration of interaction between ritonavir-containing COVID-19 therapies and small-molecule kinase inhibitors (KIs) in patients with cancer. METHODS: Physiologically based pharmacokinetic modeling was used to conduct virtual clinical trials with a parallel group study design in the presence and absence of ritonavir (100 mg twice daily for 5 days). The magnitude and time course of changes in KI exposure when coadministered with ritonavir was evaluated as the primary outcome. RESULTS: Dosing of ritonavir resulted in a > 2-fold increase in steady-state area under the plasma concentration-time curve and maximal concentration for six of the 10 KIs. When the KI was coadministered with ritonavir, dose reductions to between 10% and 75% of the original dose were required to achieve an area under the plasma concentration-time curve within 1.25-fold of the value in the absence of ritonavir. CONCLUSION: To our knowledge, this study provides the first data to assist clinicians' understanding of the drug interaction risk associated with administering ritonavir-containing COVID-19 therapies to patients with cancer who are currently being treated with KIs. These data may support clinicians to make more informed dosing decisions for patients with cancer undergoing treatment with KIs who require treatment with ritonavir-containing COVID-19 antiviral therapies.

Prescribing intranasal steroids in HIV-positive patients: systematic review of the literature.

BACKGROUND: There are significant drug-drug interactions between human immunodeficiency virus antiretroviral therapy and intranasal steroids, leading to high serum concentrations of iatrogenic steroids and subsequently Cushing's syndrome. METHOD: All articles in the literature on cases of intranasal steroid and antiretroviral therapy interactions were reviewed. Full-length manuscripts were analysed and the relevant data were extracted. RESULTS: A literature search and further cross-referencing yielded a total of seven reports on drug-drug interactions of intranasal corticosteroids and human immunodeficiency virus protease inhibitors, published between 1999 and 2019. CONCLUSION: The use of potent steroids metabolised via CYP3A4, such as fluticasone and budesonide, are not recommended for patients taking ritonavir or cobicistat. Mometasone should be used cautiously with ritonavir because of pharmacokinetic similarities to fluticasone. There was a delayed onset of symptoms in many cases, most likely due to the relatively lower systemic bioavailability of intranasal fluticasone.

Lopinavir/Ritonavir: A Review of Analytical Methodologies for the Drug Substances, Pharmaceutical Formulations and Biological Matrices.

Lopinavir/ritonavir is a potent coformulation of protease inhibitors used against HIV infection. Lopinavir is the main responsible for viral load suppression, whereas ritonavir is a pharmacokinetic enhancer. Both of them have recently gained relevance as candidate drugs against severe coronavirus disease (COVID-19). However, significant beneficial effects were not observed in randomized clinical trials. This review summarizes the main physical-chemical, pharmacodynamic, and pharmacokinetic properties of ritonavir and lopinavir, along with the analytical methodologies applied for biological matrices, pharmaceutical formulations, and stability studies. The work also aimed to provide a comprehensive impurity profile for the combined formulation. Several analytical methods in four different pharmacopeias and 37 articles in literature were evaluated and summarized. Chromatographic methods for these drugs frequently use C8 or C18 stationary phases with acetonitrile and phosphate buffer (with ultraviolet detection) or acetate buffer (with tandem mass spectrometry detection) as the mobile phase. Official compendia methods show disadvantages as extended total run time and complex mobile phases. HPLC tandem-mass spectrometry provided high sensitivity in methodologies applied for human plasma and serum samples, supporting the therapeutic drug monitoring in HIV patients. Ritonavir and lopinavir major degradation products arise in alkaline and acidic environments, respectively. Other non-chromatographic methods were also summarized. Establishing the impurity profile for the combined formulation is challenging due to a large number of impurities reported. Easier and faster analytical methods for impurity assessment are still needed.

Spontaneous reported cardiotoxicity induced by lopinavir/ritonavir in COVID-19. An alleged past-resolved problem.

The antiretroviral drug lopinavir/ritonavir has been recently repurposed for the treatment of COVID-19. Its empirical use has been associated with multiple cardiac adverse reactions pertaining to its ancillary multi-channel blocking properties, vaguely characterized until now. We aimed to characterize qualitatively the cardiotoxicity associated with lopinavir/ritonavir in the setting of COVID-19. Spontaneous notifications of cardiac adverse drug reactions reported to the national Pharmacovigilance Network were collected for 8 weeks since March 1st 2020. The Nice Regional Center of Pharmacovigilance, whose scope of expertise is drug-induced long QT syndrome, analyzed the cases, including the reassessment of all available ECGs. QTc ≥ 500 ms and delta QTc > 60 ms from baseline were deemed serious. Twenty-two cases presented with 28 cardiac adverse reactions associated with the empirical use of lopinavir/ritonavir in a hospital setting. Most adverse reactions reflected lopinavir/ritonavir potency to block voltage-gated potassium channels with 5 ventricular arrhythmias and 17 QTc prolongations. An average QTc augmentation of 97 ± 69 ms was reported. Twelve QTc prolongations were deemed serious. Other cases were likely related to lopinavir/ritonavir potency to block sodium channels: 1 case of bundle branch block and 5 recurrent bradycardias. The incidence of cardiac adverse reactions of lopinavir/ritonavir was estimated between 0.3% and 0.4%. These cardiac adverse drug reactions offer a new insight in its ancillary multi-channel blocking functions. Lopinavir/ritonavir cardiotoxicity may be of concern for its empirical use during the COVID-19 pandemic. Caution should be exerted relative to this risk where lopinavir/ritonavir summary of product characteristics should be implemented accordingly.

Use of Darunavir-Cobicistat as a Treatment Option for Critically Ill Patients with SARS-CoV-2 Infection.

We retrospectively reviewed patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections who were admitted to an intensive care unit in Daegu, South Korea. The outcomes of patients who did (cases) or did not (controls) receive darunavir-cobicistat (800-150 mg) therapy were compared. Fourteen patients received darunavir-cobicistat treatment, and 96 received other antiviral therapy (controls). Overall, the darunavir-cobicistat group comprised patients with milder illness, and the crude mortality rate of all patients in the darunavir-cobicistat group was lower than that in the controls [odds ratio (OR) 0.20, 95% confidence interval (CI) 0.04-0.89, p=0.035]. After 1:2 propensity-score matching, there were 14 patients in the darunavir-cobicistat group, and 28 patients in the controls. In propensity score-matched analysis, the darunavir-cobicistat group had lower mortality than the controls (OR 0.07, 95% CI 0.01-0.52, p=0.009). In conclusion, darunavir-cobicistat therapy was found to be associated with a significant survival benefit in critically ill patients with SARS-CoV-2 infection.