0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
ARTICLE |

Safety of Intramuscular Influenza Immunization Among Patients Receiving Long-term Warfarin Anticoagulation Therapy

Guna Raj, MD; Raminder Kumar, MD; W. Paul McKinney, MD
Arch Intern Med. 1995;155(14):1529-1531. doi:10.1001/archinte.1995.00430140104011.
Text Size: A A A
Published online

Background:  The effect of influenza vaccine on the prothrombin time (PT) among patients taking warfarin is unclear, as previous studies have shown conflicting results and the clinical significance of such a purported effect is uncertain. Moreover, to our knowledge, there are no data confirming the safety of intramuscular injections in patients receiving anticoagulant therapy with regard to possible local hematoma formation. We measured the effect of influenza vaccine on the PT among patients receiving long-term warfarin sodium therapy and evaluated the safety of intramuscular injections among them.

Methods:  Forty-one adult patients who were receiving anticoagulant therapy were given 0.5 mL of influenza vaccine intramuscularly. Prothrombin time and arm girth were measured at baseline and on days 3, 7, and 14 after immunization. Local pain and tenderness were assessed on a five-point scale. Patients and study nurses were blinded to all prior measurements. Differences between baseline PT and that at each subsequent visit and the maximal change in arm circumference from baseline were calculated for each patient. Mean, range, and 95% confidence intervals were calculated for the entire group.

Results:  There was no statistically significant change in PT between baseline and days 3, 7, and 14 after vaccination, and no significant change in arm circumference was noted. There were no clinically detectable local complications after intramuscular injection and no major or minor bleeding episodes after influenza vaccination.

Conclusions:  Influenza vaccine has no significant effect on the PT in patients who are being treated with warfarin. Influenza vaccine can be administered intramuscularly to patients who are receiving anticoagulant therapy without the risk of local bleeding complications.(Arch Intern Med. 1995;155:1529-1531)

Topics

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Figures

Tables

References

Correspondence

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
Submit a Comment

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Web of Science® Times Cited: 20

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Related Content

Customize your page view by dragging & repositioning the boxes below.

Jobs
brightcove.createExperiences();