[Intramuscular route for the administration of the anti-flu vaccine in patients receiving oral anticoagulation therapy].
OBJECTIVE
Comparison of safety and effectiveness of the intramuscular (IM) (deltoid) vs subcutaneous (s.c.) administration of the flu vaccine (FV) in patients on oral anticoagulation therapy.


METHODS
It was a phase IV, simple blind, 2-parallel groups, randomized trial developed in an urban primary care setting. We included patients taking oral anticoagulation therapy without FV contraindications. The IM administration of the FV in the experimental group was compared with a SC administration in the control group.


RESULTS
59 patients were included. The two groups were comparable at the beginning of the study. INR was not modified following s.c. (p = 0.38) or i.m. (p = 0.49) administration. No systemic side effects were observed. More cutaneous lesions were observed in the S.C. group (71.4%) when compared with the i.m. group (25.8%; p < 0.0001). For the remaining variables, we observed a tendency towards more reported pain in the SC group (35.7 vs 22.6%) and a larger brachial diameter (42 vs 29%) without significant differences. 3.2% of patients in the i.m. group and 7.1% in the s.c. group developed influenza symptoms without significant differences.


CONCLUSIONS
Even though the results must be interpreted with caution, currently there appears to be no apparent contraindication for the i.m. administration of the FV. When it is administered subcutaneously, it tends to cause more side effects.
Ballester Torrens
María del Mar
Mdel M
EAP Ramon Turró, Barcelona, Spain.
Aballí Acosta
Miriam
M
Maudos Pérez
María Teresa
MT
Iglesias Pérez
Begoña
B
Casajuana Brunet
Josep
J
Losada Doval
Gustavo
G
Piqueras Garré
María del Mar
Mdel M
D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method
D000925:Anticoagulants; D007252:Influenza Vaccines