1. Off-target effect of high-dose sildenafil on adenosine 5'- diphosphate and collagen-induced platelet activation through mitogen-activated protein kinase pathway in treated BALB/C mice and in vitro experiments: A preliminary study.
- Author
-
Balaji S, Patnaik YR, and Surin WR
- Subjects
- Adult, Animals, Humans, Male, Mice, Blood Platelets drug effects, Blood Platelets metabolism, Dose-Response Relationship, Drug, MAP Kinase Signaling System drug effects, Mice, Inbred BALB C, Mitogen-Activated Protein Kinases drug effects, Mitogen-Activated Protein Kinases metabolism, Phosphodiesterase 5 Inhibitors administration & dosage, Phosphodiesterase 5 Inhibitors adverse effects, Phosphodiesterase 5 Inhibitors pharmacology, Phosphorylation, Adenosine Diphosphate pharmacology, Collagen, Platelet Activation drug effects, Sildenafil Citrate administration & dosage, Sildenafil Citrate adverse effects, Sildenafil Citrate pharmacology
- Abstract
Abstract: Sildenafil, a common over-the-counter pill often self-administered at high doses for erectile dysfunction, has been reported to rarely cause prothrombotic events and sudden cardiac death in a few case reports. Therefore, we investigated the in vitro and in vivo effect of sildenafil treatment and dosage on platelet activation and mitogen-activated protein kinase (MAPK) phosphorylation. BALB/C mice were segregated into four groups, each having four mice each (control, low [3.25 mg/kg], medium [6.5 mg/kg], and high [13 mg/kg] sildenafil), and after the treatment, blood was drawn from each mouse and washed platelets prepared. Washed platelets were incubated with CD41 PE-Cy7 and Phospho-p38 MAPK PE antibodies and analyzed using a flow cytometer for platelet activation and adenosine 5'- diphosphate (ADP)/collagen-induced MAPK phosphorylation. Washed platelets obtained from the venous blood of 18 human volunteers, were incubated with PAC-1 FITC and Phospho-p38 MAPK PE antibodies, and platelet activation (ADP and collagen), followed by flow cytometry analysis. There was a significant increase in both platelet activation as well as MAPK phosphorylation in the presence of collagen in the high-dose (13 mg/kg) sildenafil group (P = 0.000774). Further, increased platelet activation was observed in samples that were treated with high-dose sildenafil as compared to the untreated samples (P < 0.00001). These studies show the risk of prothrombotic episodes in patients on high-dose sildenafil (100 mg), in those with even mild endothelial dysfunction due to ADP, and collagen-induced platelet activation through MAPK phosphorylation, which was not seen in the low-and intermediate-dose cohorts., (Copyright © 2024 Copyright: © 2024 Indian Journal of Pharmacology.)
- Published
- 2024
- Full Text
- View/download PDF