Do Hot Or Cold Drinks Affect Amoxicillin Absorption?

Answer

Thanks for reaching out and great question!

Although studies have found that the temperature of a beverage can slightly affect gastric emptying (i.e., how quickly food or other substances move from the stomach to the gastrointestinal tract), it generally isn't clinically significant.

Additionally, when it comes to medication, there is little evidence to suggest that the temperature of the beverage used to swallow it will significantly affect its overall absorption.  Some studies have found that taking medication with a hot beverage may slightly increase how quickly it is absorbed, but the extent of absorption (i.e., how much of a drug is absorbed overall) is generally unaffected.

There are plenty of other factors that have a much more significant role in drug absorption, such as stomach acidity, whether or not a drug is in solution, and whether or not there is food present in the stomach.

What Do The Studies Say?

A good place to start when researching how the temperature of a beverage could affect drug absorption is to look for studies that have evaluated how temperature can affect gastric emptying, which again, is how quickly the contents of the stomach move to the intestines.

In general, the vast majority of studies find that cold beverages do delay gastric emptying, but only to a very minor degree. One such study, published in Nutrition Reviews, stated the following:

Several studies have shown that beverage temperature can slightly affect the gastric emptying rate, but only for about 10 min post-ingestion. The intragastric temperature appears to rapidly return to normal core levels and the beverage temperature has little effect on overall rates of gastric emptying.

There have not been many studies that have specifically evaluated the role the temperature of a beverage used to swallow a medication plays in the absorption of that medication.

The ones that have been published show very little overall differences in drug absorption.

One study evaluated the rate and extent of absorption of caffeine, by measuring plasma levels of the drug in those who consumed it via a hot beverage (coffee) or a cold beverage (chilled energy drink). The study found small, but no clinically significant differences in absorption:

The results of this study are consistent with previous caffeine pharmacokinetic studies and suggest that while rate of consumption, temperature of beverage and vehicle (coffee versus energy drink) may be associated with slightly different pharmacokinetic parameters, the overall impact of these variables is small.

Now, we don't have any specific studies evaluating the effects of different temperature beverages with a drug like amoxicillin. Nevertheless, based on all available evidence, while how quickly the drug is absorbed may be very slightly delayed by taking it with a cold beverage, there is no data to suggest that the overall extent of absorption of medication is affected.

It is important to note that while beverage temperature doesn't appear to significantly affect the overall absorption of most (if not all) medications, whether a not a drug is already in solution absolutely does affect absorption, which is why liquid medications tend to work faster than medication in a solid dosage form (e.g., tablets or capsules).

I have seen articles online citing a study that showed acetaminophen (the pain reliever in Tylenol) being more quickly absorbed in a hot beverage versus in a tablet form as evidence that hot beverages improve drug absorption. However, this study evaluated a drug already in solution, versus a drug in a tablet dosage form. A drug in solution absorbing more quickly than a solid dosage form, like a tablet, would be expected.

Final Words

Having taken your amoxicillin with a cold beverage will not have a significant influence on its absorption, so you don't have to worry about it in that regard.

You also asked if amoxicillin is affected by stomach acid (presumable by being exposed too long due to taking it with a cold beverage). Amoxicillin is stable in gastric acid and theoretically having the drug exposed slightly longer by taking it with a cold beverage will not negatively affect it.

Thanks again for reaching out and please do so again anytime!