Abstract: Methods and compositions for treating and inhibiting hypotension are provided. A therapeutic regimen useful in the present invention includes an arginine-free parenteral formulation administered concurrently with or followed by an arginine analog. The combination therapy provides an augmentation of the anti-hypotensive effect found by the present inventors with arginine analogs, such as N.sup..omega. -methyl-L-arginine, N.sup..omega. -amino-L-arginine or N.sup..omega. -nitro-L-arginine. These arginine analogs, otherwise described as nitric oxide synthase inhibitors, provide for a decrease in nitric oxide concentrations, and are demonstrated to elicit an increase in blood pressure in vivo, particularly in animals with cytokine and/or endotoxin induced hypotension. The parenteral formulation of the therapeutic regimen and methods of the invention are arginine-free and provide a decrease in plasma arginine levels.