Faslodex Injections: Butt v. Hip

After treatment for a herniated disc that was pressing on a nerve in my spinal cord, I was pretty leery of getting my monthly Faslodex (generic: fulvestrant) injection. For those who haven't had the pleasure, these are two large injections that are placed in the muscle. Faslodex works by breaking down estrogen receptors, which can help slow or stop growth of breast cancers that have these receptors (ER+). 

Dorsogluteal/butt site. Red is muscle and yellow is nerve. Ref #1

For the last 16 months (yay!) I've had these shots, warmed and given slowly (both important!) in the "butt" or more specifically, and medically, known as the "dorsogluteal site" (basically, back butt muscle). I've had few issues except some injection site pain and knottiness, particularly sitting on the injection site. But I also knew this site was close to the sciatic nerve, and having experienced nerve pain and subsequent relief, I really didn't want to go back. So, needless to say, I was nervous.  

 My husband asked if there was another injection site, and I was like I don't think so...but then of course I searched. It turns out there is another site that can both absorb 5 ml of injected medicine and avoid major nerves and blood vessels. This site is closet to the hip, and is known as the "ventrogluteal site" (basically, side butt muscle) or "anterior gluteal site". Extra bonus - I wouldn't have to sit on the injection sites.

Ventrogluteal/hip site Ref #2

 Ventrogluteal/hip site. Ref #1

When I went in for my injections, I asked the nurse if this were possible. She looked at the paper I brought and called the pharmacist.¹ Pharmacist green lighted it, and though she'd never done it before the nurse gave an awesome ventrogluteal intramuscular injection on both sides! No more pain at injection than usual, no fear of hitting major nerves or blood vessels, and no sitting on injection sites (have I mentioned this already?). Nurses are amazing. 

So why is the dorsogluteal (butt) site used so often? Asking around, no one I know had ever had Faslodex injections except there. It seems this is  “traditional” and the main site taught in nursing school; therefore, the one with which nurses are most familiar.^1,2 They've always warned me about sciatic nerve damage and were careful to properly position to minimize risk, but there are cases of this happening (in the literature and anecdotally).^2,3 If you’re into data, here's a paper that measured distances between these injection sites and major nerves as well as arteries (about twice as close at the dorsogluteal site).⁴ Therefore, several papers argue, and in my mind effectively, that the ventrogluteal (hip) should be the first choice for reasons mentioned above. This site is not the default in practice as far as I can tell, but I'd love to hear from people (particularly any patients or nurses!) about this.

I'm really happy with this new injection site, and thought others receiving these (or other large intramuscular injections) might be interested. Your mileage may vary, consult your healthcare professionals etc. :-)

References

1. Una Hopkins & Arias, C. Large-volume IM injections: A review of best practices. Oncol. Nurse Advis. (2013).

2. Zimmermann, P. G. Revisiting IM Injections. AJN Am. J. Nurs. 110, 60–61 (2010).

3.Wynaden, D. et al. Establishing best practice guidelines for administration of intra muscular injections in the adult: A systematic review of the literature. Contemp. Nurse 20, 267–277 (2005).

4.Coskun, H., Kilic, C. & Senture, C. The evaluation of dorsogluteal and ventrogluteal injection sites: a cadaver study. J. Clin. Nurs. 25, 1112–1119 (2016).