Heparin susceptibility factors

In the Boston Collaborative Drug Surveillance Program study mentioned above, the peak incidence of bleeding was on the third day after the start of heparin therapy, which suggests a relatively safe initial 48-hour period in systemic heparinization (18). However, bleeding can be expected at any time during therapy, if the dosage becomes excessive or if susceptibility factors, such as trauma, intervene. 

Type I heparin-induced thrombocytopenia Dots classification (BMJ 2003 327 1222-5) Dose-relation toxic effect Time-course early Susceptibility factors not known... 

Susceptibility factors previous heparin therapy, co-administration of antiplatelet drugs or oral anticoagulants... 

Dose-relation Hjrpersusceptibility Time-course Early persistent Susceptibility factors Renal disease for some forms of heparin... 

Figure 9.27 Controlled release activated by cellular infiltration and enzyme activity. Adapted from [93], The gel consists of a fibrin base with covalently bound bidomain peptides. The peptide has a domain that confers heparin binding and a domain that is susceptible to enzymatic degradation. The agent for release is a growth factor that binds with high affinity to heparin. Release is initiated by cellular invasion of the gel and local secretion of an enzyme that cleaves the peptide.

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