The right common carotid artery arises from the brachiocephalic trunk (posterior to the right sternoclavicular joint), whereas the left common carotid is a branch of the arch of the aorta and hence has a thoracic portion before it reaches the neck (posterior to the left sternoclavicular joint).
Metformin Dosing. The recommended starting dosage of metformin is  500 mg twice daily. The maximum dosage for children age 10 to 16 is 2000 mg, and for adults age 17 and older is 2550 mg. Your dose should be increased only when necessary and should be increased slowly in order to avoid side effects.
In a 2 year study, rats were given Methimazole at doses of 0.5, 3, and 18 mg/kg/day. These doses were 0.3, 2, and 12 times the 15 mg/day maximum human maintenance dose (when calculated on the basis of surface area). Thyroid hyperplasia, adenoma, and carcinoma developed in rats at the two higher doses.