Patients with photosensitivity to psoralen compounds or history of light-sensitive disease should not initiate photopheresis therapy. Patients with aphakia should not initiate photopheresis therapy because of the significantly increased risk of retinal damage due to the absence of lenses.

Special care should be exercised in treating patients who are receiving concomitant therapy with known photosensitising agents.

Oral administration of methoxsalen followed by cutaneous ultraviolet-A (UVA) exposure is carcinogenic. Because the dose of methoxsalen with THERAKOS™ PHOTOPHERESIS therapy is 200 times less than with psoralen plus ultraviolet-A light (PUVA) and the skin is not exposed to high cumulative doses of UVA light, the risk of developing skin cancer following THERAKOS™ PHOTOPHERESIS therapy may be lower

Patients exhibiting multiple basal cell carcinomas or having a history of basal cell carcinomas should be diligently observed and treated.

Methoxsalen may cause fetal harm if given to a pregnant woman. Women undergoing photopheresis should be advised to avoid becoming pregnant.