All patients who receive Foscan will become temporarily photosensitive. Precautions must be taken to avoid exposure of skin and eyes to direct sunlight or bright indoor light during the first 15 days after injection. Skin photosensitivity reactions are caused by visible light; therefore ultraviolet sunscreens provide no protection.
It is important that patients are re-introduced to normal light gradually (see the light protection guidelines for patients at the end of this section). For 6 months following Foscan treatment prolonged direct sunlight exposure of the injection site arm shall be avoided.
As a precautionary measure, if prolonged outdoor activity is planned, the injection arm should be protected by wearing a long sleeved, coloured shirt. Clinicians should be aware that most of the toxicities associated with photodynamic therapy are local effects seen as consequence of photoactivation.
Photoactivation induces local tissue damage resulting in acute inflammatory response. This response is commonly associated with oedema and pain, followed by necrosis. The photodynamic effect may also lead to damage of the surrounding tissue that may cause fistula, perforation, or vascular rupture as well as infection and subsequent sepsis.
It is therefore important that during photoactivation by laser illumination care should be taken to protect normal tissue surrounding the tumour from photoactivation by proper illumination and shielding techniques. Proactively managing the local effects and diminishing photoactivation in non-tumour areas is important to manage the risks.
Special care must be taken to prevent extravasation at the injection site. If extravasation occurs, protect the area from light for at least 3 months. There is no known benefit from injecting the extravasation site with another substance.
Adverse reactions, including cholangitis, cholecystitis, liver abscess and oesophageal perforation have been reported after unapproved use in the treatment of malignant biliary strictures and mesothelioma. There is a risk of damage of the surrounding area following photoactivation.
4 Unplanned or emergency surgical procedures where Foscan has been administered within the previous 30 days must be undertaken only if absolutely necessary and the potential benefits outweigh the risk to the patient. All precautions must be taken to avoid direct illumination of the patient with surgical lamps during these procedures.