Milnirone
Milrinone, a bipyridine derivative, is a phosphodiesterase III (PDE) inhibitor that prevents the breakdown of cAMP and cGMP. Clinically, milrinone has replaced amrinone, the prototype PDE inhibitor owing to its greater intropic potency, enhanced PDE III selectivity, shorter half life and favorable adverse effect profile.
Mechanism of action:
Milrinone's selective inhibition of PDE III leads to elevated levels of cAMP with cardiac and smooth muscle cells. Consequently, positive inotropism and arterial and venous vasodilation are observed contributing to its therapeutic action in CHF patients. These dual actions, positive inotropic and vasodilation effects have led to milrinone being termed a ‘inodilator’. When infused intravenously, there is an increase in stroke volume without significant alterations in heart rate. Despite increase in …show more content…
It has a elimination half life of 0.5-1 h which is approximately doubled in severe CHF patients. Longer elimination half-life necessitates administration of a loading dose in cases where prompt initial response is desirable. However, if rapid hemodynamic changes are not necessary or the patient has low blood pressure, bolus dose should be omitted.
Recommended dosages:
The usual loading dose of milnirone is 50 ug/kg administered slowly over 10 min. This is followed by continuous infusion rates of 0.1-0.75 ug/kg/min. Patients need to be closely monitored and infusion rates should be adjusted according to hemodynamic and clinical response. Since milrinone is excreted largely unchanged in urine, the infusion rate should be reduced by 50-70% in patients with severe renal impairment.
Adverse effects:
Most common adverse effects of milnirone are ventricular and supraventricular arrhythmias, hypotension, headache and anginal chest pain. Although clinically significant thrombocytopenia has been observed in nearly 10% patients receiving amrinone, it is rarely seen with
Milrinone, a bipyridine derivative, is a phosphodiesterase III (PDE) inhibitor that prevents the breakdown of cAMP and cGMP. Clinically, milrinone has replaced amrinone, the prototype PDE inhibitor owing to its greater intropic potency, enhanced PDE III selectivity, shorter half life and favorable adverse effect profile.
Mechanism of action:
Milrinone's selective inhibition of PDE III leads to elevated levels of cAMP with cardiac and smooth muscle cells. Consequently, positive inotropism and arterial and venous vasodilation are observed contributing to its therapeutic action in CHF patients. These dual actions, positive inotropic and vasodilation effects have led to milrinone being termed a ‘inodilator’. When infused intravenously, there is an increase in stroke volume without significant alterations in heart rate. Despite increase in …show more content…
It has a elimination half life of 0.5-1 h which is approximately doubled in severe CHF patients. Longer elimination half-life necessitates administration of a loading dose in cases where prompt initial response is desirable. However, if rapid hemodynamic changes are not necessary or the patient has low blood pressure, bolus dose should be omitted.
Recommended dosages:
The usual loading dose of milnirone is 50 ug/kg administered slowly over 10 min. This is followed by continuous infusion rates of 0.1-0.75 ug/kg/min. Patients need to be closely monitored and infusion rates should be adjusted according to hemodynamic and clinical response. Since milrinone is excreted largely unchanged in urine, the infusion rate should be reduced by 50-70% in patients with severe renal impairment.
Adverse effects:
Most common adverse effects of milnirone are ventricular and supraventricular arrhythmias, hypotension, headache and anginal chest pain. Although clinically significant thrombocytopenia has been observed in nearly 10% patients receiving amrinone, it is rarely seen with