Leaving Ativan In The Sun And High Temperatures

In our latest question and answer, the pharmacist discusses how Ativan (lorazepam) is affected by high temperatures.

May 08, 2018

Nate asked

I left my lorazepam in my backpack, and my backpack was in the sun for about two hours today. Should the medication be fine?


Ativan (lorazepam) liquids and injectable solutions are known to be particularly susceptible to degradation when exposed to high temperatures. However, there are a lack of stability studies on solid dosage forms of Ativan, such as with Ativan tablets.

Exposing Ativan (Lorazepam) To High Temperatures

Several studies have shown that exposing Ativan (lorazepam) injectable solutions to high temperatures will significantly degrade drug potency. One such study showed that there was a 75% reduction in the concentration of Ativan injectable soltuion when stored at 98° F for 210 days.

However, it is likely that exposure to high temperatures will affect solid dosage forms of Ativan (lorazepam) significantly less. Nevertheless, due to the lack of studies, we don't know just how affected they are.

When it comes to high temperatures and solid dosage forms, studies suggest that the dosage form (e.g. the tablet) is more affected than the actual drug itself. High temperatures can cause tablets to break apart easily and disintegrate when touched, making it likely you will lose some of the dose. Some drugs though, such as ones that contain hormones (e.g. birth control pills), may be less potent when exposed to high temperatures as they degrade fairly easily when not stored properly.

Going back to Ativan, the recommended storage conditions are as follows:

  • Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F)

As Ativan left in a hot car likely exceeded these temperature recommendations, it may be affected and not be as effectiveness, but the extent is unknown. It is unlikely to be harmful, it just may not work as well. Be sure to reach out to your doctor to see if they are able to refill your medication if it isn't working as well as it did before being exposed to high temperatures.

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