Manidipine Hydrochloride

The US FDA has approved paxlovid, a combination of nirmatrelvir and ritonavir, as the first oral treatment for the management of mild-to-moderate COVID-19 patients.

The purpose of this review article is to explore the clinical data that is currently available regarding the drug-drug interactions (DDIs) of paxlovid with various medications.

Keywords, such as drug interactions, paxlovid, ritonavir, nirmatrelvir, pharmacokinetic interactions, CYP3A, and P-glycoprotein, were used to search online databases, including LitCOVID, Scopus, Embase, EBSCO host, Google Scholar, ScienceDirect, Cochrane Library, and reference lists.

Paxlovid interacted with a variety of medications due to strong inhibition of CYP3A4 and P-gp transporter protein by ritonavir and the dual function of nirmatrelvir as a substrate and inhibitor of CYP3A enzymes and P-gp transporter protein. Numerous case reports and other studies determined that the risk of toxicities of several drugs, including anticoagulants (warfarin, rivaroxaban), calcium channel blockers (nifedipine, manidipine, verapamil), statins (atorvastatin), immunosuppressants (tacrolimus), antiarrhythmics (amiodarone), antipsychotics (clozapine, quetiapine), and ranolazine have been enhanced by the concomitant administration of paxlovid.

Adverse effects of paxlovid from DDIs can range from less-than-ideal therapeutic responses to potentially fatal toxicities. Effective management requires close observation, adjustments to dosage, and assessment of substitute treatments. Collaboration between pharmacists and other medical professionals is necessary to guarantee effective and safe treatment outcomes of paxlovid therapy.

Manidipine (MP) is a dihydropyridine drug, which is treated for the reduction of high blood pressure. The aim of this study is to clarify the photochemical behavior of MP in the case of ultraviolet light (UV) irradiation for MP tablets (Calslot^® tablets). The tablets and its altered forms (powders and suspensions) were UV-irradiated using a black light, and residual amounts of active pharmaceutical ingredients (APIs) were monitored by high-performance liquid chromatography (HPLC). Due to the photoproducts of MP were detected in HPLC chromatograms, the elucidation of their chemical structures was carried out utilizing electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). As a result, APIs in Calslot^® tablets were almost completely photodegraded in the case that Calslot^® tablets were suspended in an aqueous media along with the generation of some MP photoproducts. LC-ESI-MS/MS analysis clarified the chemical structures of three MP photoproducts, indicating that they were a pyridine analogue, benzophenone and a hydrolysate. Benzophenone was a main MP photoproduct. It was possible that MP might be firstly oxidized to form its pyridine analogue, followed by the oxidation of a dimethyl methylene moiety. This moiety seemed to be eliminated as a benzophenone, and the cleavage of an ester bond of the residual moiety resulted in the generation of a hydrolysate. Finally, toxicological potencies of MP and its photoproducts were predicted in silico toxicity evaluation, suggesting some of biological effects of the photoproducts might be altered compared with MP.