Technetium (Sup99m/Suptc) Exametazime Hmpao Wbc

What it is and how it works

Technetium-99m exametazime is a lipophilic complex that crosses cell membranes and is converted intracellularly to a hydrophilic form that is retained. It is used to label autologous white blood cells in vitro; after reinjection the labelled leucocytes migrate to sites of infection or inflammation. Without cell labelling it is also used for cerebral perfusion imaging.

Indications

Labelled leucocyte scintigraphy for localisation of intra-abdominal infection, inflammatory bowel disease, osteomyelitis, prosthetic and vascular graft infection and fever of unknown origin; regional cerebral perfusion scintigraphy.

Dosage and administration (summary)

Dosing is individualised according to protocol by the nuclear medicine specialist; for infection imaging, the patient’s own leucocytes are labelled in vitro with technetium-99m exametazime under aseptic conditions and reinjected intravenously.

Contraindications

Hypersensitivity to the active substance or any kit component.

Warnings and precautions

Cell labelling involves handling of patient blood and must be performed under strict aseptic conditions with positive patient identification to prevent cross-contamination or misadministration. Radiolabelling efficiency and radiochemical purity must be checked; severe leucopenia may limit labelling.

Pregnancy

Diagnostic radiopharmaceuticals should be avoided in pregnancy unless clearly necessary; exclude pregnancy before administration in women of childbearing potential.

Storage and supply

Store the unlabelled kit below 25 °C or as stated by the manufacturer; use the reconstituted product within the short time stated in the product information (labelled exametazime is unstable unless stabilised).

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.