Thank you for your post asking if there is a recommended amount of time to wait between having a flu vaccination and the first infusion of zoledronic acid (Aclasta).

There is no evidence of any interactions between zoledronic acid and flu vaccines. Usually, however, it’s recommended to delay having a flu vaccination if feeling unwell, so it may be worthwhile to allow a gap of at least a week or two if having the zoledronic acid infusion beforehand as some people may experience mild to moderate flu-like symptoms afterwards.

If these flu-like symptoms do occur with zoledronic acid, they usually happen within three days of having the infusion and tend to resolve within three days. Taking paracetamol or ibuprofen shortly after the infusion may be recommended by the doctor to help reduce the likelihood of these symptoms occurring. Experiencing these symptoms becomes less likely with each subsequent infusion.

Ultimately, whether to delay and for how long would be a medical decision. Although there appears to be no problem with regards to zoledronic acid, the doctor or nurse would need to check that there are no specific recommendations or instructions provided by the manufacturers of the flu or other type of vaccine.

Best wishes

Helpline Nurses
National Osteoporosis Society