Patients on immunosuppressive therapy have an increased risk of infections. Since infections have a potential to trigger acute porphyric attacks vigilance is motivated regarding signs or symptoms of infection and/or possible symptoms of a porphyric attack. Side effects like nausea and vomiting may potentially be porphyrinogenic through reduction in carbohydrate intake.

Infections are common in patients using immunosuppressants and since infections might trigger an acute porphyric attack, vigilance regarding signs and symptoms of an infection and/ or a porphyric attack is recommended. Common adverse reactions of antiyhymocyte immunoglobulin that can be confused with an acute porphyric attack are nausea and vomiting. These side effects may potentially be porphyrinogenic if leading to a decrease in carbohydrate intake.

Immunoglobulins are not metabolized by cytochrome P450 enzymes. There are no reports of effects on CYP-mediated clearance of other drugs. No pharmacokinetic porphyrinogenic effects are suspected.

Antithymocyte globulin (rabbit) is a polyclonal antibody preparation that contains immunoglobulin G (IgG) prepared from the sera of healthy rabbits hyper immunized against antigens expressed on human thymocytes.

Antithymocyte globulin (rabbit) is an immunosuppressive agent used in conjunction with other immunosuppressive agents for the treatment of, or to prevent or delay, acute rejection of renal allografts. It is also used for the treatment of myelodysplastic syndrome. Infectious complications, including sepsis, have been reported in 37 - 50 % of the patients receiving the drug, and fever is also very common. This is attributed to the release of cytokines by activated monocytes and lymphocytes. It is recommended to administer pre-medication with intravenous corticosteroids, antihistamines and anti-pyretic agents prior to infusion.

Proteins and macromolecules such as antithymocyte globulin are cleared by other mechanisms than P450 liver metabolism (Mahmood, 2007). Interactions with CYP-metabolism of other drugs not reported.

Antithymocyte globulin was used uneventfully after a kidney transplant in a 49 year old AIP male (El-Haggan, 2002).