Expert Perspectives on Advanced/Metastatic Prostate Cancer
In the second interview of the series, Brenda Heath, RN, examines special considerations in the preparation and administration of formulations of leuprolide acetate and leuprolide mesylate.
Leuprolide acetate is dosed in different increments. There [are] 1-month, 3-month,4-month, and 6-month doses. [It is available as] a subcutaneous (SC) version and an intramuscular (IM) version. Having the different dose ranges is very helpful [for] coordinating appointments with patients and [ensuring that they come] in for [injections] at appropriate times. Leuprolide acetate [has 2 components] that have to be mixed [to form] the product that is administered to the patient. One version does not need to be refrigerated, [but] the other version [needs refrigeration]. The [refrigerated] version has 2 separate vials [with contents] that need to be mixed … it is important to make sure that we remove [them from refrigeration] 30 minutes before [mixing]. It makes it much easier to mix together, and it's best practice for the patient [to] decrease any stinging or pain. The leuprolide acetate [that needs no refrigeration] is stored at room temperature. The mixing is a little bit different—it's filled in 1 syringe, and you just have to push the plunger up to mix the liquid and the powder together and[then] twirl [it] while it's sitting upright. They are a little bit different, for sure.
Leuprolide mesylate is new to the market here, and we're very excited about this medication. [It requires only] 1 dose, which could be a limiting factor in [using] it; however, it is already prefilled [and] premixed. It [must be] refrigerated, so it [needs] to be removed from the refrigerator 30 minutes ahead of [administration]. However, [it’s] very convenient when [we're] running an advanced prostate cancer clinic day, and [we] have a whole list of patients coming in. [It’s] convenient for the nurses to be able to pull that and already have it premixed.
Refrigeration is probably one of the biggest ones. Making sure [that] the appropriate leuprolide acetate and leuprolide mesylate are removed from the [refrigerator] 30 minutes ahead of time can be difficult and challenging to complete with a full schedule. However, [we] are also factoring in the mixing and the premixed injectables and different doses that can come into play. Having [those] 1-, 3-, 4-, [and] 6-month doses can be important as opposed to just the 6-month dose, especially when we have patients who are going to Florida—we may want to meet up with them [in the summer] and give them a 4-month [dose] so that we can give them a 6-month [dose] in November. By the time they return, they are appropriately due for their next injection.
They are all agonists, so they all have that potential tumor flare in the beginning. However, they all seem to work comparably at maintaining the testosterone at castrate levels. As long as that testosterone is castrate, their PSA (prostate-specific antigen) suppression is usually pretty good, but, as we know in this day and age, depending on the disease space and the disease that the patient has, we are typically mixing this with another oral oncolytic to keep that PSA [level] down. We are rarely utilizing just leuprolide acetate or leuprolide mesylate as a monotherapy unless it is [given as adjuvant therapy] with radiation.
The [AEs] are pretty similar, the top 2 being hot flashes and fatigue. However, they can differ in how they're administered. [For] the leuprolide acetate that's administered IM … I have patients who don't really complain about the IM injections. [This drug and administration route] don't [cause] any site irritation [or] lump. [In comparison], the leuprolide acetate or the leuprolide mesylate that is administered via SC [injection] to the abdomen can cause a little discomfort [and] some stinging. There can be a bump at the site of administration. Those are the differences that … account for the different medications.
Some physicians like to start out with a lower dose of leuprolide … and make sure that the [patient isn’t] going to have any AEs and [that] they're going to tolerate it well. Obviously, the most important thing … is making sure that the patient is at a castrate level, so testosterone castration and suppression of the PSA [are] the highest and most important [priorities] that we're looking for with these medications.
Having the prefilled syringe [of leuprolide mesylate] is definitely much more convenient for the flow of the schedule. That is huge—just being able to pull that medication out ahead of time and administer it when it's already premixed. However, once again, the refrigeration can come into play, [so we should] make sure [that we remove] it from [the refrigerator] 30 minutes ahead of time, especially if [we need to give] multiple injections that day. That can come into play, as well. The main considerations are [whether the formulation is] premixed [and] refrigerated [or needs] mixing and [is] nonrefrigerated.
Transcript has been edited for clarity.