Jiaci

59 / 80

Practitioner's Corner
J Investig Allergol Clin Immunol 2019; Vol. 29(5): 378-398 © 2019 Esmon Publicidad
as premedication in an attempt to reintroduce the drug with
tolerance. A provocation test was programmed for 2 days to
achieve a total dose of 1000 mg of abiraterone. The protocol
on the first day comprised 50 mg, 150 mg, and 300 mg, with a
1-hour interval between doses and 2 hours of observation after
the last dose (cumulative dose, 500 mg). Ten hours after the
challenge was completed, the patient developed a pruriginous
micropapular rash on the thorax, affecting the groins and the
axillas (Supplementary Material, Photo). Once the Urology
Department confirmed that abiraterone was the first‐choice
agent for this patient, we developed a desensitization protocol
(Table) in collaboration with the Pharmacy Department.
Doses were prepared by weighing the corresponding amount
of powder (10 mg, 30 mg, and 125 mg) and filling empty
gelatine capsules. Dextrin maltose was used as the excipient.
The desensitization protocol was stepped up every 3 days
at the hospital, starting with the 10‐mg dose; the patient
maintained the maximum tolerated dose at home (Table). We
decided to premedicate the patient with ebastine 20 mg/24 h
and prednisone 15 mg/12 h. Once the total dose was reached,
ebastine was stopped, and prednisone was stepped down,
continuing with 10 mg/12 h during the following 2 days
and maintaining 5 mg/12 h, as per the summary of product
characteristics of abiraterone. The patient did not experience
any problems or adverse events during the protocol, which
was fully tolerated. Allergic reactions to anticancer drugs are
a growing problem in allergology clinics, and desensitization
protocols are useful when the drug involved is a first‐choice
option [3]. Rapid desensitization in IgE‐mediated reactions
has well‐defined pathophysiological mechanisms, and
while the procedure is risky, it has proven to be safe and
efficacious [4]. In the case of late reactions (ie, more than
1 hour after administration), which are similar to those in
the present case and are also frequently managed with rapid
desensitization [5], there is no consensus on the ideal protocol,
Safe and Successful Protocol for Desensitization to
Abiraterone
Núñez-Acevedo B1, Rubio-Pérez M1, Padial-Vilchez A1, de la
Morena-Gallego JM2, Barro-Ordovás JP3, Reche-Frutos M 1,
Valbuena-Garrido T1
1Allergy Department, Hospital Universitario Infanta Sofía, San
Sebastián de los Reyes, Madrid, Spain
2Urology Department, Hospital Universitario Infanta Sofía, San
Sebastián de los Reyes, Madrid, Spain
3Pharmacy Department, Hospital Universitario Infanta Sofía,
San Sebastián de los Reyes, Madrid, Spain
J Investig Allergol Clin Immunol 2019; Vol. 29(5): 386-387
doi: 10.18176/jiaci.0408
Key words:Abiraterone. Desensitization. Drug Allergy.
Palabras clave:Abiraterona. Desensibilización.Alergia a medicamentos.
Abiraterone acetate is used for the treatment of castration‐
resistant metastatic prostate cancer. It acts as a selective
inhibitor of the enzyme 17 α‐hydroxylase/C17,20‐lyase
(CYP17). Expression of this enzyme is necessary for the
synthesis of androgens in the testicles, adrenal glands, and
prostate tumor tissue; therefore, inhibition leads to reduced
production of androgens. Given that inhibition of CYP17 also
leads to increased production of mineralocorticoids by the
adrenal glands, abiraterone should be taken with prednisone.
While abiraterone is generally well tolerated, the summary of
product characteristics and various studies list hypertension,
hypokalemia, and hepatotoxicity as common adverse
effects [1,2]. We present the case of a 63‐year‐old man with a
personal history of hypothyroidism and sleep apnea hypopnea
syndrome treated with continuous positive airway pressure
who was diagnosed with prostate cancer (Gleason 4+5) and
bone metastasis (T10 and left iliac spine). The patient had an
initial clinical response to treatment with enzalutamide. As
he remained asymptomatic, his urologist decided to maintain
hormone treatment instead of taxane-based therapy, starting
with abiraterone 1000 mg every 24 hours, together with
prednisone 5 mg every 12 hours. After 4 days of treatment,
the patient developed a fairly symmetrically distributed
micropapular rash on the trunk (mainly the abdomen), both
groins, and the root of the upper limbs. He also complained
of axillary pruritus, although no lesions were visible at this
level. There was no fever or mucous membrane involvement.
He was evaluated in the urology department, where treatment
was suspended. The rash resolved 4 days later, with minimum
fine desquamation and no residual lesions.
We carried out an allergological work‐up starting with skin
prick tests at 200 mg/mL, although the result was negative.
We decided not to perform patch tests, because standardized
options with abiraterone are lacking. Even though the rash was
indicative of a drug reaction, the fact that it was not severe
led us to assess oral tolerance after adding ebastine 20 mg
Table. Desensitization Protocol
Day 1
Doses administered at hospital with 10 mg
30-minute intervals 20 mg
40 mg
60 mg
125 mg
Day 2 and Day 3
Dose at home 125 mg
Day 4
Dose at hospital 250 mg
Day 5 and Day 6
Doses at home 250 mg
Day 7
Dose at hospital 500 mg
Day 8 and 9
Doses at home 500 mg
Day 10
Dose at hospital 1000 mg
386