[e-farmacos] Agranulocitosis y medicamentos en el JAMA

["Canas, Martin" <macanas@netverk.com.ar>]

Luisa Ibanhez; Xavier Vidal; Elena Ballarin; Joan-Ramon Laporte. 
Population-Based Drug-Induced Agranulocytosis  Arch Intern Med. 
2005;165:869-874.
http://archinte.ama-assn.org/cgi/content/abstract/165/8/869?etoc

Background:  Since the publication of a major international case-control 
study on the risk of agranulocytosis associated with the use of medicines in the 1980s, many new drugs have been introduced in therapeutics.

Methods:  Seventeen units of hematology contribute to the case-control 
surveillance of agranulocytosis and aplastic anemia in Barcelona, Spain. 
After a follow-up of 78.73 million person-years, 177 community cases of 
agranulocytosis were compared with 586 sex-, age, and hospital-matched 
control subjects with regard to previous use of medicines.

Results: The annual incidence of community-acquired agranulocytosis was 
3.46:1 million, and it increased with age. The fatality rate was 7.0%, and 
the mortality rate was 0.24:1 million. The drug most strongly associated 
with a risk of agranulocytosis was ticlopidine hydrochloride with an odds 
ratio (OR) of 103.23 (95% confidence interval [CI], 12.73-837.44), followed 
by calcium dobesilate (OR, 77.84 [95% CI, 4.50-1346.20]), antithyroid drugs 
(OR, 52.75 [95% CI, 5.82-478.03]), dipyrone (metamizole sodium and 
metamizole magnesium) (OR, 25.76 [95% CI, 8.39-179.12]), and spironolactone 
(OR, 19.97 [95% CI, 2.27-175.89]). Other drugs associated with a significant risk were pyrithyldione, cinepazide, aprindine hydrochloride, carbamazepine, sulfonamides, phenytoin and phenytoin sodium, -lactam antibiotics, erythromycin stearate and erythromycin ethylsuccinate, and diclofenac sodium. Individual attributable incidences for all these drugs, which collectively accounted for 68.6% of cases, were less than 1:1 million per year.

Conclusions:  Agranulocytosis is rare but serious. A few drugs account for 
two thirds of the cases. Our results also provide reassurance regarding the 
risk associated with a number of newly marketed drugs.

Saludos,

Martin

Martin Canas
La Plata 
(Argentina)
macanas@netverk.com.ar