Medrol Left In Cold Car Overnight

Answer

While there is always going to be some concern with having your medication exposed to temperatures outside of the recommended storage conditions, the chance of medication being negatively affected depends on a great many factors, including what the medication in question is, what temperature it was exposed to, how long it was exposed, etc...

In regard to leaving your Medrol Dose Pack (methylprednisolone) overnight in a cold car in freezing conditions, it is unlikely that the medication will be negatively affected. In other words, it will likely still work as intended and retain its labeled potency.

I have written about this topic on a few other occasions (such as this one) and the point I try to get across is that some drugs are far more susceptible to cold temperatures than others (such as drugs in liquid dosage forms, insulin, protein-based drugs, etc...).

For example, several studies have found that frozen temperatures can affect some protein-based drugs due to the potential damage that can happen during the thawing and recrystallization process.

However, many conventional drugs in a tablet dosage form, and aren't known to be particularly sensitive to cold, are generally going to be ok if they are left in freezing temperatures for a little while, which can certainly happen during the drug distribution process (or when drugs are delivered by mail, as they often sit in a mailbox for some time).

Although there are very few studies that have evaluated the potentially negative effects of cold temperatures on non-protein-based drug tablets (like Medrol), the studies that are available have shown they there is not an appreciable loss of potency when kept at cold temperatures. Several of the studies I am referring to can be found here, here, and here.

What we're really more concerned with as it pertains to the Medrol Dose Pack, are the physical tablets.

Medrol Dose Pack Storage

According to the manufacturer, a Medrol Dose Pack is recommended to be stored as follows:

Store at controlled room temperature 20° to 25°C (68° to 77°F) [see USP]

There have been no studies or data to suggest that a Medrol Dose Pack being stored at temperatures lower than recommended reduces the potency of the drug or otherwise makes it less effective (unlike some of the other drug examples I listed in the above section).

There is some data to suggest that another dosage form of Medrol, methylprednisolone acetate sterile suspension, should not be frozen as particulates can form in the suspension, which is a danger since the drug is made to be injected. Again though, there is no data showing Medrol tablets are negatively affected.

Are They Safe To Take?

While I wouldn't make a habit of storing Medrol at lower than recommended temperatures, as mentioned, we are more concerned with the physical tablets than the actual drug being affected.

No available data suggests that a Medrol Dose Pack, if left temporarily at frozen temperatures, will be less effective or harmful.

However, take a look at the physical tablets. If the tablets in your Medrol Dose Pack look warped, discolored, or are fragile enough that they are breaking apart, I would get them replaced simply due to the fact that the tablets may be physically degraded and you won't be getting a full dose due to tablet loss.

A Medrol Dose Pack is, fortunately, relatively inexpensive and if you think the drug has been compromised, you can't go wrong with getting a new prescription.

Final Words

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