I have a small aneurysm, 5mm, in the carotid artery, facing the right eye and high blood pressure.is lozartan 100mg-12.5 mg, adecuate to lower my blood pr?

Can't say: It certainly can be. You and your doctor need to monitor your bp. No medicaine is always effective.

It is a start: I would check with your pcp what kind of blood pressure control you are having before deciding what is the best way to change it. That being said, a 5mm aneurysm is big enough for treatment so you should be evaluated further in regards to this.