Pharmacotherapeutic group: Omega-3-triglycerides including other esters and acids; ATC code: C10AX06.
The omega-3 series polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential fatty acids.
Mechanism of action
Omega-3-acid ethyl esters 90 are active on the plasma lipids by lowering triglyceride levels as a result of a fall in VLDL (very low density lipoprotein), and the substance is also active on haemostasis and blood pressure.
Pharmacodynamic effects
Omega-3-acid ethyl esters 90 reduce the synthesis of triglycerides in the liver because EPA and DHA are poor substrates for the enzymes responsible for triglyceride synthesis and they inhibit esterification of other fatty acids.
The increase in peroxisomes of β -oxidation of fatty acids in the liver also contributes to the fall in triglycerides, by reducing the quantity of free fatty acids available for their synthesis.
The inhibition of this synthesis lowers VLDL.
Omega-3-acid ethyl esters 90 increase LDL-cholesterol in some patients with hypertriglyceridaemia. A rise in HDL-cholesterol is only small, significantly smaller than seen after administration of fibrates, and not consistent.
The long-term lipid-lowering effect (after more than one year) is not known. Otherwise there is no strong evidence that lowering triglycerides reduces the risk of ischaemic heart disease.
During treatment with Omega-3-acid ethyl esters 90, there is a fall in thromboxane A2 production and a slight increase in bleeding time. No significant effect has been observed on the other coagulation factors.
Clinical efficacy and safety
11324 patients, with recent MI (<3 months) and receiving a recommended preventative treatment associated with a Mediterranean diet, were randomised in the GISSI-Prevenzione study in order to receive Omega-3-acid ethyl esters 90 (n=2836), vitamin E (n=2830), Omega-3-acid ethyl esters 90 + vitamin E (n=2830) or no treatment (n=2828). GISSI-P was a multicentre, randomised, open-label study performed in Italy.
The results observed over 3.5 years, with Omega-3-acid ethyl esters 90 1g/day, have shown a significant reduction of a combined endpoint including all-cause death, non fatal MI and non fatal stroke (decrease in relative risk of 15% [2-26] p=0.0226 in patients taking Omega- 3-acid ethyl esters 90 alone compared to control, and of 10% [1-18] p=0.0482 in patients taking Omega-3-acid ethyl esters 90 with or without vitamin E). A reduction of the second pre-specified endpoint criteria non-fatal stroke has been shown (decrease in relative risk of 20% [5-32] p=0.0082 in patients taking Omega-3-acid ethyl esters 90 alone compared to control, decrease in relative risk of 11% [1- 20] p= 0.0526 in patients taking Omega-3-acid ethyl esters 90 with or without vitamin E).