Patent Blue Sodium

1. Health Canada Product Monograph — Patent Blue Sodium

• Patent blue sodium is injected to mark lymphatic vessels and arterial territories during surgical or diagnostic procedures.
• It is used to locate the sentinel lymph node before biopsy in patients with operable breast cancer and clinically negative lymph nodes, usually combined with a radioactive tracer.
• It is used to help confirm correct catheter placement during intra-arterial chemotherapy by producing visible coloration of the tissue supplied by the targeted vessel.

• The safety of patent blue sodium during pregnancy has not been established, so its use is discouraged unless clearly needed for the procedure.

• It is not known whether patent blue sodium passes into breast milk, as this has not been studied.

• No age-specific dosing data or special precautions have been established for older adults; the same single-injection administration applies regardless of age.

• No pediatric-specific safety or dosing data are available for patent blue sodium; its use in children should be guided by a specialist experienced with the marking procedure.

• For marking lymphatic vessels, approximately 1 mL of patent blue sodium is injected into the subcutaneous tissue, typically at the base of the large toe in the foot, or between the metacarpals, at the thenar or hypothenar prominence, or at the elbow in the upper limb.
• For marking arterial territories, patent blue sodium is combined with an isotonic solution and a local anesthetic and infused intra-arterially to confirm catheter placement before intra-arterial chemotherapy.
• For sentinel lymph node marking before breast cancer biopsy, patent blue sodium is injected subcutaneously around the tumour or around the nipple before surgery, typically combined with a radioactive tracer for improved detection.
• Total subcutaneous or intravascular dosing for lymphatic and arterial marking generally ranges from 1 to 10 mL.
• Patients must be monitored for at least 30 minutes after the injection because of the risk of a delayed hypersensitivity reaction.

If overdose is suspected, seek emergency medical attention immediately or contact your regional Poison Control Centre without delay.

• This product's monograph does not include a dedicated overdosage section, as it is a single-dose diagnostic dye administered by a healthcare professional rather than a self-administered medication.
• The monograph describes that severe hypersensitivity reactions, if they occur, can include low blood pressure, nausea, swelling of the throat, and cardiovascular collapse, and that resuscitation equipment should be readily available whenever the dye is given.

• Temporary blue or greenish-blue discoloration of the skin near the injection site is expected and usually fades within 24 to 48 hours.
• Temporary discoloration of the urine may occur as the dye is eliminated from the body.
• Discoloration lasting longer than 48 hours may occur in patients with lymphatic stasis or circulatory disorders.

Serious side effects require immediate discussion with the prescriber or emergency care.

• Anaphylactic shock, a severe and potentially fatal allergic reaction, may occur, sometimes within minutes of the injection.
• Hypersensitivity reactions can present as hives (urticaria) and pale green or blue-tinged swelling of the skin (angioedema), including swelling of the lips or eyelids.
• Bronchospasm (wheezing or difficulty breathing) may occur as part of a hypersensitivity reaction.
• Severe reactions may include low blood pressure, nausea, swelling of the throat (laryngeal edema), and cardiovascular collapse.
• Seek immediate medical attention for any signs of a severe allergic reaction during or shortly after the injection.

• Use with caution in patients with a personal history of hypersensitivity to patent blue sodium or to other triphenylmethane dyes found in some other medicines, foods, or cosmetics.
• Use with caution in patients taking beta-blockers, since epinephrine and other resuscitation measures used to treat a severe allergic reaction may be less effective in these patients.
• Before administration, patients should be carefully interviewed for any history of allergic reactions, and an indwelling intravenous catheter should be placed in case urgent treatment is needed.
• Resuscitation equipment and medications must be immediately available whenever patent blue sodium is administered, given the risk of severe hypersensitivity reactions.
• Patent blue sodium can cause a temporary false decrease in blood oxygen saturation and a false increase in serum methemoglobin when measured by spectrophotometry; confirm with arterial blood gas analysis if results are unexpected during the same procedure.

• Contraindicated in patients with known hypersensitivity to patent blue sodium, to any excipient in the formulation, or to other triphenylmethane dyes.

• No formal drug-drug interaction studies have been conducted with patent blue sodium.
• Patients taking beta-blockers may have a reduced response to epinephrine and other treatments used for a hypersensitivity reaction, so caution and close monitoring are warranted if a reaction occurs.
• Patent blue sodium can interfere with spectrophotometric measurement of blood oxygen saturation and serum methemoglobin, producing falsely altered readings during the same procedure.

• No food interactions have been established for this injectable diagnostic dye.

• Patent blue sodium is given as a single injection immediately before or during the surgical or diagnostic procedure it is used for, rather than on a fixed daily schedule.

• Store ampoules at room temperature, protected from light, in their original packaging until use.

• Patent blue sodium is a blue dye injected once during a surgical or diagnostic procedure to help a surgeon see lymphatic vessels or find the sentinel lymph node.
• Expect temporary blue discoloration of your skin near the injection site and possibly your urine for a day or two after the procedure.
• You will be monitored for at least 30 minutes after the injection because of a small but serious risk of a severe allergic reaction.
• Tell your healthcare team about any past allergic reaction to blue dyes, foods, or cosmetics, or if you take a beta-blocker, before this procedure.