Bob asked
Yesterday I experienced some adverse side effects from a 1200 mg Mucinex DM tablet that I took - general weakness, headache and forearm swelling. Since I've been taking it for years with no problem, this came as a surprise. One thing peculiar that I did notice however, was was that the tablet was odorous and bitter to the taste. I speculated that if the time-release mechanism was compromised due to coating deterioration, I could have received an overdose. My question is whether I can store the tablets in a refrigerator since I live in a humid climate and can't guarantee a 68-77 degree room temperature at all times.
Answer
Most drugs, including Mucinex, should not be stored in the refrigerator as this could potentially increase the rate at which the medication degrades.
However, when it comes to Mucinex specifically, keeping it in the refrigerator may be a better option if there is no other alternative to the high temperatures it is being exposed to at home.
How Cold Temperatures Affect Medication
There is a plethora of data available on the dangers of storing medication in conditions that are too hot. Excess heat will most certainly degrade medications at a much faster rate than when stored appropriately. However, there is far less data on how too cold temperatures affect medication.
Data indicates specific types of medication are susceptible to cold temperatures. These include:
- Biologics (e.g. protein based medications)
- Insulin
- Liquid dosage forms
With insulin for example, studies indicate when insulin is frozen and then thawed, there is definitive evidence of breakdown. Frozen insulin products show both "particle clumping" and "crystal damage", which most likely lowers the overall effectiveness of the medication.
Other studies indicate that any drug that contains a protein or consists of an emulsion should not be frozen if that is not the recommended storage.
Freezing and then thawing these products can increase the risk of non-solubilized particles, which can cause pulmonary embolisms. In addition, protein drugs can have powerful "shear" and "tension" forces exerted on them when exposed to periods of freezing and thawing.
Storing Mucinex In The Refrigerator
How low temperatures can affect solid dosage forms, such as Mucinex tablets, isn't well known. It would make sense to assume that solid dosage forms are less susceptible to degradation from freezing and cold temperatures than other dosage forms, but data is lacking.
Studies on solid dosage forms of medication and cold temperatures indicate that the actual dosage form (e.g. the tablet) is more likely to be affected than the actual medication.
As solid dosage forms contain trace amounts of moisture, storing in cold conditions could potentially reduce the moisture content of them (as cold air holds less moisture than warm air), damaging the integrity of the dosage form. In addition, putting a medication in the fridge could make it susceptible to water damage from condensed moisture (i.e. condensation).
To reiterate, the main concerning issue in regard to keeping Mucinex in the refrigerator is we just don't know exactly how it will be affected by cold temperatures. Drug companies will do stability tests on their products at a certain temperature range. Most do not study the affect of cold temperatures on their products, Mucinex included.
Nevertheless, if your Mucinex product is blister packed, that would be the ideal way to store it in the refrigerator. Although we can't know for sure, storing Mucinex in the refrigerator may be a better option than exposing to high temperatures as we know far better the negative effects of hot temperatures on medication.
