Pharmacodynamics of CY 216 in healthy volunteers: inter-individual variations

Area of Science:

• Pharmacology
• Pharmacokinetics
• Biochemistry

Background:

• Low molecular weight heparin (LMWH) is widely used for anticoagulation.
• Understanding the pharmacodynamic variability of LMWH is crucial for safe and effective clinical use.
• CY 216 is a specific LMWH preparation whose dose-response relationship requires detailed investigation.

Purpose of the Study:

• To investigate the pharmacodynamic parameters and inter-individual variations of a low molecular weight heparin (LMWH, CY 216).
• To compare the effects of intravenous (IV) and subcutaneous (SC) administration of CY 216.
• To assess the clinical implications of observed pharmacokinetic and pharmacodynamic variability.

Main Methods:

• A crossover study involving 12 healthy volunteers.
• Administration of 100 anti-factor Xa IU/kg of CY 216 via IV or SC routes, one week apart.
• Monitoring of pharmacological effects using activated partial thromboplastin time (APTT), thrombin clotting time (TCT), and a chromogenic anti-factor Xa assay.

Main Results:

• After IV injection, APTT ranged from 56-98 sec and TCT from 28-99 sec, with anti-factor Xa activity of 1.58-2.28 IU/ml and a half-life of 1.5-2.9 h.
• After SC injection, no significant APTT or TCT prolongation was observed; maximum anti-factor Xa activity was 0.36-0.88 IU/ml with a half-life of 1.5-6.4 h.
• Significant inter-individual variations in pharmacodynamic parameters were observed for both administration routes.

Conclusions:

• CY 216 exhibits substantial inter-individual variability in its anticoagulant effects, similar to standard heparin.
• The route of administration (IV vs. SC) significantly influences the measured pharmacodynamic parameters.
• These findings highlight the importance of considering individual patient responses when determining CY 216 dosage.