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Should I Use Powder Vials or Act-o-vials?

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Medical providers recommend 100mg powder vials of Solu-Cortef for use in the pump (NDC# 0009-0825-01) (Hindmarsh, Geertsma 2017). These differ from the Act-o-vials in that the powder vials only contain the powdered Solu-Cortef and the mixing solution must be ordered separately. This may seem like an inconvenient extra step, but it is actually the easiest and least problematic option.

Medical providers recommend 100mg powder vials of Solu-Cortef for use in the pump (NDC# 0009-0825-01)

Powder Vials: Easier to Understand Ratio

With powder vials, pumpers can use a 1:1 mixing ratio. This means 1mg is equal to one unit in the pump. This is achieved by adding 1mL of solution to each 100mg powder vial. This makes calculating delivery rates and milligrams easier for pumpers. A 1:1 dilution ratio has also been shown to absorb more effectively and produces more ideal blood cortisol levels than the 2:1 dilution ratio used with the 2mL Act-o-vials (Hindmarsh, Geertsma 2017 p. 371). Reading this, you may be thinking a 2:1 ratio is not much more complicated, it’s only doubling the units, however in times of low cortisol this simple math becomes rather difficult for pumpers. Low cortisol creates enough confusion on it’s own, throwing math into the mix while figuring boluses or basal changes is a layer of frustration a pumper in distress does not need.

Powder Vials: Better pH Level

Pumpers in the United States have reported a lower pH with the Solu-Cortef Act-o-vials than what is stated on the packaging (Hindmarsh, Geertsma 2017 p. 374). This was found to affect multiple lot numbers in the United States, and was reported to Pfizer in 2012 by both pumpers and medical providers. Pfizer responded that they would look into the issue. It is unknown if any action has been taken. The lower pH level in the Act-o-vials can cause skin irritation for some pumpers depending on their level of sensitivity.

Act-o-Vials: More Difficult to Place in Reservoirs

Act-o-vials are inconvenient to use with Medtronic reservoirs. The reservoirs have a needle attachment that is designed for insulin vials. These attach well to the powder vials of Solu-Cortef, but are not compatible with the Act-o-vials. Pumpers using Act-o-vials with Medtronic pumps will either need to use a separate needle and syringe to work around this problem (which does have some slight risk of damaging the reservoir), or they can find a way to remove the Act-o-vial top (which not only risks damaging the vial, but could also introduce germs).

Act-o-Vials: Potentially Cheaper

While powdered vials of Solu-Cortef are the preferred preparation, be aware that with a few insurance plans, the Act-o-vials are less expensive. Check your insurance plan’s formulary to determine which option is the most financially feasible in order to make an informed decision.

Find out more:

Where Can I Learn More about the Cortisol Pump?

How Do I Program the Basal Rates for My Cortisol Pump?

How Do I Use The Pump When I’m Sick?


Hindmarsh, P. C., & Geertsma, K. (2017). Congenital adrenal hyperplasia: a comprehensive guide. London: Elsevier/Academic Press.