Methyldopa is an aromatic-amino acid decarboxylase inhibitor. It inhibits the decarboxylation of
L-DOPA [
D0600], thereby interfering with the formation of dopamine [
A0305 (HCl salt)], a precursor of
L-norepinephrine [
A0906 (bitartrate)]. Methyldopa is an effective anti-hypertensive agent that reduces both supine and standing blood pressure. At first, the anti-hypertensive activity was believed to be related with the inhibition. Nowadays, methyldopa is metabolized to α-methylnorepinephrine and this compound is thought to stimulate central nerve α-adrenergic receptors, producing a decrease in peripheral sympathetic outflow, and resulting in decreasing blood pressure. (The product is for research purpose only.)