DOSAGE AND ADMINISTRATION
Photodynamic therapy for non-hyperkeratotic actinic keratoses with Metvixia Cream is a multi-stage process as described below: Two treatment sessions 7 days apart should be conducted. Not more than one gram (half a tube) of Metvixia Cream should be applied per treatment session.
One Metvixia -PDT session consists of:
1) Lesion debriding –
Before applying Metvixia Cream, the surface of the lesions should be prepared with a small dermal curette to remove scales and crusts and roughen the surface of the lesion. This is to facilitate access of the cream and light to all parts of the lesion.
Figure 1 A Lesion debriding
Only nitrile gloves should be worn during this and subsequent steps and Universal Precautions should be taken. Vinyl and latex gloves do not provide adequate protection when using this product.
Figure 1B Lesion debriding
2) Application of Metvixia Cream –
Using a spatula, apply a layer of Metvixia Cream about 1 mm thick to the lesion and the surrounding 5 mm of normal skin. Do not apply more than one gram of Metvixia Cream for each patient per treatment session.
Figure 2: Cream application
The area to which the cream has been applied should then be covered with an occlusive, non-absorbent dressing for 3 hours. Multiple lesions may be treated during the same treatment session. Each treatment field is limited to a diameter of 55 mm. Only nitrile gloves should be worn by the qualified healthcare provider in order to avoid skin contact with the cream. This product is not intended for application by patients or unqualified medical personnel.
Figure 3: Occlusive dressing application
3) Wait for 3 hours - (at least 2.5 hours, but no more than 4 hours).
After Cream application, patients should avoid exposure of the photosensitive treatment sites to sunlight or bright indoor light (e.g., examination lamps, operating room lamps, tanning beds, or lights at close proximity) during the period prior to red light treatment. Exposure to light may result in a stinging and/or burning sensation and may cause erythema and/or edema of the lesions. Patients should protect treated areas from the sun by wearing a wide-brimmed hat or similar head covering of light-opaque material. Sunscreens will not protect against photosensitivity reactions caused by visible light. It has not been determined if perspiration can spread the Metvixia Cream outside the treatment site to the eyes or surrounding skin. The treated site should be protected from extreme cold with adequate clothing or remaining indoors between application of Metvixia Cream and PDT light treatment.
4) Removal of Dressing and Rinse Off Excess Cream - Following removal of the occlusive dressing, clean the area with saline and gauze. Nitrile gloves should be worn at this step by the trained physician.
Figure 4: Cream removal
5) Illumination of Metvixia Treated Lesion - It is important to ensure that the correct light dose is administered. The light intensity at the lesion surface should not be higher than 200 mW/cm2. Patient and operator should adhere to safety instructions and Universal Precautions provided with the lamp. The patient and operator should wear protective goggles during illumination. Patients should be advised that transient stinging and/or burning at the target lesion sites may occur during the period of light exposure.
Figure 5: Illumination
The CureLight BroadBand Model CureLight 01 lamp is approved for the use in Metvixia -PDT. The lamp should be carefully calibrated so that dosing is accurate and immediately thereafter the lesion should be exposed to red light with a continuous spectrum of 570 to 670 nm and a total light dose of 75 J/cm2. To avoid direct contact between lamp parts and patient skin, always use disposable protective plastic sleeves on the positioning device and on the light measuring probe. Following each patient treatment, the disposable protective plastic sleeves should be removed from the positioning device and from the light measuring probe and discarded.
If red light treatment is interrupted or stopped for any reason, it may be restarted. If the patient for any reason cannot have the red light treatment during the prescribed period after application (the 3 hour timespan), the cream should be rinsed off and the patient should protect the exposed area from sunlight, prolonged or intense light for two days. Metvixia Cream is not intended for use with any device other than the approved lamp: CureLight BroadBand Model CureLight 01.
Use of Metvixia Cream without subsequent red light illumination is not recommended.
No more than 1 gram (half a tube) of product should be used for each of the two weekly treatment sessions. Multiple lesions may be treated during the same treatment session using a total of 1 gram of Metvixia Cream. Lesion response should be assessed 3 months after the last treatment session.
This product is not intended for application by patients or unqualified medical personnel, therefore, this product is only dispensed to physicians.