Anaphylaxis, infusion associated reactions (IAR), cytokine release syndrome and serum sickness (see below) are rare but potentially fatal reactions which have been reported. Reactions such as flushing, rash, erythema, oedema, dyspnoea with or without bronchospasm and cough are commonly observed during and after the administration.Cytokine release related symptoms include: fever, chills, headache, nausea, vomiting, tachycardia and circulatory changes. These reactions usually respond well to treatment.
Prophylactic medication may be administered to alleviate these symptoms. Reduction in infusion rates may minimise the incidence of reactions. The occurrence of anaphylaxis/anaphylactic shock requires immediate termination of the infusion and medical treatment.
An immune-complex mediated reaction, may occur in patients after treatment with antithymocyte globulin (ATG). Serum sickness presents with significant morbidity but is usually self-limiting or resolves rapidly with corticosteroid treatment. Symptoms usually develop 7 to 21 days after the start of treatment with ATG. However, some patients may develop symptoms in 1 to 3 days if they have previously been exposed to ATG.
Prophylaxis with corticosteroids may reduce the frequency of this reaction. If serum sickness does develop:
- high dose corticosteroids may be prescribed as treatment for severe cases
- antihistamines and corticosteroid creams or ointments may relieve the discomfort of itching and rash.
Infections, reactivation of infections such as cytomegalovirus (CMV) and sepsis have been reported after ATG administration. There is increased risk of infection especially when ATG is given in combination with immunosuppressive agents.
Close monitoring of patient and appropriate anti-infective prophylaxis are recommended. Appropriate anti-infective therapy should be given if infection occurs.
Thrombocytopenia and leukopenia are common and transient adverse effects. Anaemia is commonly observed after administration of ATG-Fresenius S and fulminant haemolysis has been reported rarely with ATGAM administration for which transfusion of erythrocytes may be required. Platelet and white cell counts generally return to normal without interrupting therapy and with transfusions.
Monitor blood counts prior to and throughout ATG therapy. Dose reductions may be required for concomitant immunosuppressive and/or ATG therapy.
Malignancies including, but not limited to post-transplant lymphoproliferative disease (PTLD) and other lymphomas as well as solid tumours have been rarely reported with Thymoglobuline® and ATG-Fresenius S®. These adverse events were always associated with a combination of multiple immunosuppressive agents.
Close monitoring of patient throughout and after the completion of treatment is recommended.
Live vaccinations should not be administered to patients being treated with ATGAM® for the duration of their therapy and for 6 months after treatment with ATGAM®. Patients should be advised that other vaccinations might be less efficacious.
Live vaccines are contraindicated in immunocompetent persons and cancer patients receiving immunosuppressive therapy and/or those who have poorly controlled malignant disease.
Refer to the recommended schedule of vaccination for immunocompromised persons, as outlined in the Australian Immunisation Handbook 10th edition (updated 2018).