Sodium nitroprusside should not be used for compensatory hypertension (e.g. due to an anteriovenous stent or coarctation of the aorta).[6] It should not be used in patients with inadequate cerebral circulation or in patients who are near death. It should not be used in patients with vitamin B12 deficiency, anaemia, severe renal disease, or hypovolaemia.[6] Patients with conditions associated with a higher cyanide/thiocyanate ratio (e.g. congenital (Leber's) optic atrophy, tobacco amblyopia) should only be treated with sodium nitroprusside with great caution.[6] Its use in patients with acute congestive heart failure associated with reduced peripheral resistance is also not recommended.[6] Its use in hepatically impaired individuals is also not recommended, as is its use in cases of pre-existing hypothyroidism.[5]