Doses - METHYLENE BLUE

Dogs:

To preferentially stain islet-cell tumors of the pancreas:
a) 3 mg/kg in 250 ml sterile normal saline and administered IV over 30-40 minutes intraoperatively. Initial tumor staining requires approximately 20 minutes after infusionhas begun and is maximal at about 25-35 minutes after infusion is started. Tumorsgenerally appear to be a reddish-violet in color versus a dusky blue (backgroundstaining). (Fingeroth and Smeak 1988)

Ruminants:

Note: Methylene blue can be obtained from various chemical supply houses, but there hasbeen some concern raised that the FDA will not allow it to be used in food animals as it is asusepected carcinogen. It is recommended to contact the FDA before treating for guidancewhen contemplating using this compound.
For methemoglobin-producing toxins (nitrites, nitrates, chlorates):
a) Cattle: 8.8 mg/kg by slow IV using a maximum of a 1% solution; repeat if necessary.
To prevent hypotension during nitrite poisoning, give a sympathomimetic drug such asepinephrine or ephedrine. (Bailey 1986b)
b) Cattle: 4.4 mg/kg IV in a 2-4% solution. (Ruhr and Osweiler 1986)
c) Cattle, sheep: 8.8. mg/kg slow IV as a 1% solution in normal saline; may repeat carefully in 15-30 minutes if response is not satisfactory. Other species should use 4.4mg/kg dosage rate (as above). (Hatch 1988b)
For cyanide toxicity:
a) 4 - 6 g IV per 454 kg (1000 lb.) of body weight. (Oehme 1986b)
Monitoring Parameters -

1) Methemoglobinemia

2) Red cell morphology, red cell indices, hematocrit, hemoglobin
Client Information - Because of the potential toxicity of this agent and the seriousness ofmethemoglobin-related intoxications, this drug should be used with close professional supervisiononly. Methylene blue may be very staining to clothing or skin. Removal may be accomplishedusing hypochlorite solutions (bleach).
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products: None.

Human-Approved Products:

Methylene Blue Injection 10 mg/ml in 1 ml and 10 ml amps; Generic; (Rx)Methylene Blue Tablets 65 mg Methblue 65® (Manne Co);Urolene Blue® (Star) (Rx)
Methylene Blue, U.S.P. powder may be available from chemical supply houses.