Inhibition of amikacin on platelet aggregation and blood coagulation

Objective To observe the inhibition of amikacin in vitro on platelet aggregation and blood coagulation tests, and to study its effects on hemostasis and the related mechanisms.Methods Plateletrich plasma and platelet-poor plasma from donors were mixed with different concentration of amikacin, which was divided into four groups:0 mg/L, 30 mg/L, 91 mg/L and 910 mg/L group.The maximial ratio of platelet aggregation induced by ADP were measured with Platelet Aggregation Analyzer.The expression levels of P-selectin, GP Ⅱ b/Ⅲ a and Fg-R were determined with Flow Cytometer.The PT, APTT, TT and Fg of platelet-poor plasma were detected with Blood Coagulation Analyzer. The four concentration of amikacin mentioned above and two anticoagulants (62.5 U/ml of sodium heparin and 109 mmol/L of sodium citrate)were interacted with fresh whole blood, in which the blood CT and plasma Ca2+ were detected. Blood samples were collected from 10 patients with acute lower respiratory tract infection before and 30 minutes after routine amikcin treatment respectively.The maximial ratio of platelet aggregation, the expression levels of P-selectin, GPⅡ b/Ⅲa and Fg-R induced by ADP were measured; while PT, APTT, CT and plasma Ca2+ were determined.Results At 30 mg/L of amikacin group, the maximal ratios of platelet aggregation (65.8±3.9)%, the expression levels of P-selectin (9.2 ± 1.0)% and Fg-R (12.6 ± 1.7)% were statistically lower than those [(88.0 ±4.6%, (16.1 ± 1.3)% and (31.0 ±2.5)%]at 0 mg/L of amikacin group ( t = 9.442,8.432,9.993,P ＜ 0.01 ). At 30 mg/L of amikacin group, the APTT (80.5 ±6.8) s and CT ( 857 ± 66) s were significantly higher than those [(33.0 ± 3.6) s and (447 ± 35 ) s] at 0 mg/L of amikacin group ( t = 11.312, 13.211, P ＜ 0.01 ). There was a negative correlation between amikacin concentration and maximial ratio of platelet aggregation ( r = - 0.832, P ＜ 0.05 ), but a positive correlation between amikacin concentration and inhibitory rates of platelet aggregation ( r = 0.939, P ＜0.05) was observed, as well as APTT (r ＞0.870, P＜0.05). At 30 mg/L, 91 mg/L, and 910 mg/L of amikacin groups, the P-selectin and Fg-R expression were remarkably inhibited with a dose-dependent manner, the CT was notably enhanced [Fwithin subjects =21.44, 26.24, ( ＞29.81 ), P ＜0.01]. At 0 mg/L,30 mg/L, 91 mg/L and 910 mg/L of amikacin groups, the PT values were ( 14.7 ± 1.9) s, ( 15.2 ± 1.7) s,(15.6±1.5) s and (22.1 ±2.1) s, respectively (F=8.21,P＜0.05), but there was no markeddifference for the levels of GP Ⅱ b/Ⅲ a, TT, Fg and plasma Ca2+ among the four groups ( P ＞ 0.05 ). After 30 minutes of amikacin treatment, the maximial ratio of platelet aggregation (51.6 ± 10.1)%, the expression levels of P-selectin (6.8 ± 1.8) % and Fg-R ( 20.1 ± 5.8 ) % were significantly lower than those [(66.8 ± 11.4)%, ( 10.9 ±3.1 )% and (28.5 ±7.4)%] before amikacin treatment, but APTT (49.8 ±5.9) s and CT (660 ±59) s were remarkably higher than those [(26.9 ±3.8) s and (410 ±45) s] before amikacin treatment, respectively ( t = 5.456,8.875,7.423,10.012,11.322, P ＜ 0.01 ), while the GP Ⅱ b/Ⅲ a expression, PT and Ca2+ concentration had no significant changes ( P ＞ 0.05). Conclusions There are inhibitory effects of amikacin on platelet aggregation mainly through the inhibition of both fibrinogen receptor activation and secretion reaction of activated platelet. Amikacin may also inhibit pathway of coagulation system factor to prevent blood coagulation.Therefore, risk of hemorrhage may be investigated in the patients with amikacin for anti-infection treatment. Key words: Amikacin; Platelet aggregation; Blood coagulation; Receptors,fibrinogen