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Mary Shomon

WARNING: Hot Temperatures May be Hazardous to Your Drugs

By August 3, 2006

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As a summer heatwave and power outages continue to plague many parts of the U.S., there's another casualty of the heat we may not realize: our prescription medications.

One reader in Los Angeles during the recent heat wave wrote me to say "I didn't become aware that the extreme heat had compromised the potency of my pills until I started feeling really lousy a few days later."

If you take any prescription drug, you need to be aware that storage at high temperatures can quickly degrade the potency and stability of your medication. I spoke with Abbott Labs' consumer medical hotline today, and learned that they do not recommend taking their drug Synthroid if it's been stored at temperatures above 86 degrees.

Basically, "controlled room temperature" for storage of most drugs tops out at 86°F. Levothyroxine drugs-- such as Synthroid, Levoxyl, Levothroid, Unithroid, and generic levothyroxine -- should be stored away from light and moisture, and at a temperature no higher than 86°F. This temperature standard also applies to Cytomel (liothyronine), Armour (desiccated thyroid), and the antithyroid drugs PTU and methimazole. (NOTE: Thyrolar (liotrix) should be refrigerated, at a temperature no higher than 46°F.)

If you are in one of the areas of extreme 90-degree-plus heat, and do not have air conditioning in your home, you've flown with medication in the luggage comparment, you've traveled with your medication in a hot car, or you have experienced a power outage at home or at your pharmacy, you probably need to replace your medication.

Your first step? Talk to your pharmacist and see what he or she recommends.

Your next step should be a call to your health insurance company, who may reimburse you for a replacement prescription.

Finally, Synthroid's consumer hotline suggested that it's possible -- not guaranteed however -- that Abbott and other drug makers may be able to offer some form of reimbursement for damaged medications, so if you get nowhere with your pharmacy or insurance company, you may want to contact the manufacturer as well.

Keep in mind that these guidelines don't just apply to thyroid medications. You should be sure to check the storage instructions for any prescription medications you take, and talk to your doctor and pharmacist right away about any drugs exposed to higher temperatures.

August 3, 2006 at 4:57 pm
(1) Linda says:

I am so glad you posted this! I left my pills in the car in the heat for a few days and 3 days later feeling really hypo…

August 3, 2006 at 9:52 pm
(2) Nhan says:

Hi Everybody

This is not a comment. this is a problem, so please help or tell me what is the best way to do.

Now I am having thryroid in my body, and my doctor told me that I don’t have to do surgery (thyroid is not big), but if I do. Then I have to take medicine all my life, that is what I dont want. So who ever knew this disease, please tell me what should I do?

E-mail: thankytruongky@yahoo.com

August 3, 2006 at 10:49 pm
(3) MJ Hardy says:

This problem of heat sensitivity of many drugs is something that really bothers me about insurance companies that require mail order for chronic medications. There is NO way to guarantee that medications shipped in the mail are maintained at temperatures that will not damage the medication. Many drugs are heat labile, and if you get a 90 days supply of a medication that has been damaged, you may not even realize it until your blood pressure goes up enough to cause a stroke, or your blood thinner doesn’t work and you have a heart attack. Certainly insulins should never be shipped in the summer unless in an insulated cooler. We should not allow insurance companies to force us to get our prescriptions from the mail order houses. We must let our employers know of this major concern.

August 4, 2006 at 3:59 am
(4) Genie in AZ says:

Just an aside to MJ Hardy’s comment…
while mail order meds during weather extremes (both hot OR freezing temps)
most definitely affect the efficacy, what makes anyone think the trucks that deliver meds to the pharmacies are
“climate controlled” ??? Sure, SOME meds are delivered to pharmacies “cooled”… but that represents only a tiny minority of the shipment. Perhaps a better idea is to have lab work performed AT LEAST once a year (more
often if you receive meds-by-mail).

August 4, 2006 at 6:09 am
(5) Anne says:

For Genie;
Yeah, that would be nice, right- But how about those of us who cannot afford to be getting all those lab tests done??? I know I am not alone in this respect- And so, those of us who cannot, we then find ourselves self-medicating. When I feel ‘hypo’ I will take my entire prescribed dose; when I am feeling ‘hyper’ I take half or 3/4 of a pill. I know this isn’t right; but I also know that there are many times during any given year that our bodies call for more/less thyroid prep. Running to the doctor at these times is NOT an option.
Has anyone mentioned keeping our pills in the fridge? This should be a controlled environment…

August 4, 2006 at 7:44 am
(6) Liliana says:

Recently I traveled to Europe. To get there and back home my medication was exposed to six radiations. That made me feel lousy. I am sure that x-ray can make your medicine loose potency.

August 4, 2006 at 10:19 am
(7) Denise says:

Hi thank you.. im inthe Uk and we too have had some really hih temps l was wondering about my meds l do block and replace and l always carry them in my handbag!! Well some days my bag has been hot too touch so l guess my tablets have been ‘really hot’ too!! Just had my blood done today and see the endo next week if the labs are high l am going to suggest the medication/heat maybe too blame. Thank you for the info x

August 4, 2006 at 11:09 am
(8) Gin says:

Wow… I have been feeling horrible since the heat wave in CA a couple of weeks ago. I keep my synthroid next to my bed (upstairs), so I don’t forget to take it when I get up. During the extreme heat, the AC was not able to cool the upstairs. I began sleeping in the dining room downstairs, but my pills remained upstairs during the heat! Maybe that’s why I can’t seem to recover…?

August 4, 2006 at 11:10 am
(9) Susan says:

What amount of time in high temps are we talking about? Would a day in a hot car make a big difference?

August 4, 2006 at 11:23 am
(10) carol says:

thank you for all that you do, Mary. Your site is the most comprehensive and compassionate. thank you also for providing me with the knowledge that YES, FOREST PHARMACEUTICALS IS ONCE AGAIN DISPENSING THYROLAR. for those who have never tried this medication for hypothyroidism, it is a wonder drug. i now take Armour also dispensed by Forest but my body has never felt quite the same as when i took Thyrolar. Forest Pharmaceuticals shelved Thyrolar for several years much to my dismay. Thyrolar must be refrigerated. Thank you, Mary!

August 4, 2006 at 2:40 pm
(11) Ed Arnold says:

What ever happened to the idea of a temperature sensor button included in each shipment? I read about this years ago. Supposedly, mail-order houses were going to include an inexpensive sensor in each shipment which would change color permanently if the shipment got too hot. Is this just another casualty of the pharmacy price wars?

August 4, 2006 at 4:59 pm
(12) Nancy Smith says:

I have been feeling really dizzy and kinda sick to my stomach would that be coming from my meds getting to hot?

August 4, 2006 at 6:15 pm
(13) lizlk says:

In Australia refrigerating of thyroid medications have been implemented by the company. We also get our medications dispensed (in 5 x 40 tablet bottles with instructions to discard the tablets after 40 days of opening). Once opened the tablets can be stored at room temperature as long as it is less than 25 deg C. I am very careful with medications and heat and absolutely agree about the article.

August 4, 2006 at 11:31 pm
(14) Linja says:

Twice I got my Armour Thyroid via mail order because it was cheaper and both times I noticed that my energy was much lower than with the Rx from Wal-Mart pharmacy. I think this is due to exposure to heat, although it is also possible that the pills were not as fresh.

Also, my basal temperature ran slightly lower on the mornings following taking the mail-order pills, although this could be a coincidence since the difference is less than one degree. But the difference in energy was quite noticeable.

August 6, 2006 at 1:37 am
(15) foster471@bellsouth.net says:

there are very small regrigerators that cost about fourty dollars for when traveling. that plugs into were cigerette lighter goes. especially good for insulin. but good for all drugs. when not in use. for drinks.

August 7, 2006 at 8:56 am
(16) Chris says:

I also have been feeling really dizzy and sick to my stomach. Could this be from my meds getting too hot?

August 7, 2006 at 11:51 am
(17) Jan says:

I had to get my synthyroid prescription refilled yesterday, so I asked the pharmacist about this issue. He felt that although prolonged heat (like in a car) is a problem, so is refrigeration because of the moisture problem, which will also breakdown the potency.

August 7, 2006 at 4:21 pm
(18) Denise R. says:

Thank you, Mary, for this important topic & the helpful comments from others. I have been wondering about the effect of temps. on drugs the insurance copanies force us to get my mail for some time & never saw anyone mention it until one of your gracious readers here. We really need to try to get together & do something about this.

August 8, 2006 at 7:14 am
(19) tali says:

you r always being very helpful for readers all over the world. it would help even more if u put in brackets the celsius equivalent, for us in the warm parts of Asia! Thanx!!

March 1, 2014 at 3:48 pm
(20) Angie says:

My question has to do with extremes in the OTHER direction, namely freezing temps. I recently received dessicated thyroid that took over two weeks to get to my house during the last “blizzard” event in the South. Could this also affect potency? I’m experiencing a return of some symptoms (including bradycardia) on my new batch of meds.

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