Indications: methaemoglobinaemia; a dye in diagnostic procedures such as fistula detection and the diagnosis of rupture amniotic membranes.

Cautions: SC injection causes necrotic abscesses; intrathecal injection causes neural damage; severe renal impairment; pregnancy and breast-feeding.

Contra-indications: patients with G6PD-deficiency; methaemoglobinaemia induced by sodium nitrite during the treatment of cyanide poisoning; methaemoglobinaemia due to chlorate poisoning.

Dose: drug-induced methaemoglobinaemia, by IV injection as a 1% solution, 1-2mg/kg over a period of several minutes.