There are disclosed methods useful for the inhibition of inducible nitric oxide synthase by the adminstration of a compound of the formula I:. when R.sub.2 is H then R.sub.1 is selected from the group consisting of:1) aryl,--NH--C.sub.0 -C.sub.10 alkyl -aryl, N-(C.sub.0 -C.sub.10 alkyl substituted aryl).sub.2, --C.sub.0 -C.sub.10 alkyl substituted aryl, --N(C.sub.0 -C.sub.10 alkyl substituted aryl)(C.sub.0 -C.sub.10 alkyl), wherein "Aryl" is optionally attached to Compound I through C or N and is selected from the group consisting of isoindanolyl, isoindolinyl, tetrahydroquinolyl, phenyl, naphthyl, pyridyl, furyl, pyrryl, thienyl, isothiazolyl, imidazolyl, benzimidazolyl, triazolyl, tetrazolyl, pyrazinyl,pyrimidyl, quinolyl, isoquinolyl, benzofuryl, benzothienyl, pyrazolyl, indolyl, isoindolyl, purinyl, carbazolyl, isoxazolyl, thiazolyl, oxazolyl, benzthiazolyl, and benzoxazolyl; and the term "substituted aryl" denotes mono-, di- and/or tri-substituted aryl wherein aryl is as defined above and in which the substituents are independently selected from the group consistng of H, trifluoromethyl, amino, hydroxy, halo, nitro, --O--C.sub.1 -C.sub.6 alkyl, --S--C.sub.1 -C.sub.6 alkyl, --NH--C.sub.1 -C.sub.6 alkyl, --N (C.sub.1 -C.sub.6 allyl).sub.2, --C(O) --C.sub.1 -C.sub.6 alkyl, --NHC(O) C.sub.1 -C.sub.6 alkyl, --C.sub.1 -C.sub.11 COO.sub.2 R wherein R.dbd.C.sub.1 -C.sub.11 alkyl, or --C.sub.1 -C.sub.11 alkylphenyl, --C.sub.1 -C.sub.11 CONHR wherein R.dbd.C.sub.1 -C.sub.11 alkyl or C.sub.1 -C.sub.11 alkylphenyl, carboxy, --C(O) O C.sub.1 -C.sub.6 alkyl; trans-CH.dbd.CHCO.sub.2 R; wherein R.dbd.C.sub.1 -C.sub.11 alkyl or C.sub.1 -C.sub.6 alkylphenyl, trans CH.dbd.CHCONHR; wherein R.dbd.C.sub.1 -C.sub.11 alkyl or C.sub.1 -C.sub.11 alkylphenyl;2) cyclic --N(CH.sub.2 CH.sub.2).sub.2 Y, cyclic NCHA(CH.sub.2).sub.3, or --NH C.sub.2 -C.sub.11 alkyl-Y wherein A=i) C.sub.1 -C.sub.10 alkyl, C.sub.1 -C.sub.10 alkylaryl or,ii) COZR.sub.3 wherein Z=oxygen, NH and R.sub.3 =H, or C.sub.1 -C.sub.10 alkyl, or C.sub.0 -C.sub.10 alkylaryl wherein aryl group is as defined in (1) above, and Y=i) oxygen,or S, or NH orii) NC.sub.0 -C.sub.10 alkyl oriii) NC.sub.1 -C.sub.10 alkylsubstituted aryl,iv) NC=ZMR.sub.3 or COZR.sub.3 wherein Z=oxygen, or NH; M=C, oxygen, N, and R.sub.3 is C.sub.0 -C.sub.10 alkyl substituted aryl; wherein Z is as defined in (2iv) above and R.sub.3 is C.sub.0 -C.sub.10 alkylsubstituted aryl wherein "substituted aryl" is as defined above.; R.sub.2 is hydrogen; or R.sub.1 and R.sub.2 taken together forming another aryl group; and X is hydrogen, halo, alkyl, alkoxy, hydroxy, nitro, amino, trifluoromethyl and aryl, to a patient in need of such inhibition such as hypotension, inflammtion, autoimmune diseases, and septic shock and the like.