Treatment of Infantile Spasms with Tetracosactide (Synthetic ACTH)

Abstract

We would like to report a patient who, while receiving tetra-cosactide (synthetic ACTH), developed a blood picture consistent with overwhelming infection. However, the clinical presentation was masked. Because of the high incidence of side effects reported with tetracosactide, 1 we recommend that the natural form be used preferentially over the synthetic.A 3-year-old Saudi female was diagnosed as having infantile spasms. She was severely mentally retarded, and computerized tomographic (CT) scan of the brain showed evidence of generalized brain atrophy and a cystic space consistent with porencephaly. Her flexor spasms were not controlled by conventional anticonvulsants and she was admitted for trial therapy with ACTH.A tapering ACTH dosage regimen was planned for the patient, starting at 120IU daily and gradually reducing it to a final daily dose of 20 IU over a period of 20 days. Since natural ACTH was not available, tetracosactide (Organon, synthetic form) was used in equivalent dosages (1 mg = 100 IU ACTH). The patient's white blood count (WBC) and differential were within normal limits.On the seventh day of therapy, after a total dose of 3.5 mg, the child developed a low-grade fever of 38°C and she appeared less active. Clinically, it was difficult to assess a change in her baseline of activity since it was always low. Crepitations were evidenced upon auscultation and chest X-ray. Tetraco-sactide was discontinued. Blood cultures and complete blood count (CBC) were drawn. The WBC was 21,000/mm3, with a differential showing 10% polymorphs, 5% lymphocyes and 63% band forms. The chest X-ray revealed "abnormal hazy shadows, suggestive of an early inflammatory lesion." Intravenous gentamicin and cloxacillin were instituted. The child had no further episodes of fever and blood cultures were reported as negative. After three days of intravenous antibiotics a repeat CBC showed WBC 25,200/mm3, with 71% polymorphs, 22% lymphocytes and 3% band forms. Clinically, she appeared well and more alert.Synthetic ACTH (tetracosactrin) is frequently used instead of the natural form for the treatment of infantile spasms. The literature indicates that it is associated with a much higher incidence of side effects and more fatal outcomes than the natural ACTH, 2,3 the most common complication being infection. A case of marked leukocytosis without evidence of infection after tetracosactrin has been previously reported. The use of tetracosactide for treatment of infantile spasms is not recommended.2 We agree and feel that its use is potentially dangerous because, as demonstrated by our patient, severe infection can be effectively masked while rendering interpretation of monitoring parameters ambiguous. We feel that the natural form of ACTH should be used preferentially, when available.