↑ indicates a slight increase in clotting time;↑↑, moderate increase in clotting time;↑↑↑, marked increase in clotting time; PC, protein C; and PS, protein S.

*Using thromboplastin containing a heparin neutralizer.

†Effect is method dependent; most fibrinogen assays show no effect.

‡Levels may be decreased physiologically, but the assay per se is not affected by the drug.

§When drug levels are supratherapeutic.

¶Assay effect is hypothesized based on drug action.