Urine Odor From Amoxicillin
In our latest question and answer, the pharmacist discusses urine odor due to the antibiotic amoxicillin.
I have been prescribed Amoxicillin after a dental procedure, but I have not noticed a change in the odor of my urine as before when I or my children have been prescribed this drug. Could my pills be duds?
Aug 21, 2022- Amoxicillin can cause urine odor because about 60% of the drug is excreted unchanged in your urine within 6-8 hours of taking it.
- Urine odor from amoxicillin does not mean the medication is ineffective or defective.
- Factors like food intake, hydration level, and the manufacturer of your medication can influence whether you notice an odor.
Thanks so much for reaching out to us! A change in urine odor is certainly a possible side effect of amoxicillin but the absence of a smell doesn't indicate that the medication will be ineffective, or is a dud.
Why Does Amoxicillin Have An Odor?
Amoxicillin is known to cause urine to have a slight odor to it in many individuals due to the fact that most of the drug is excreted in the urine within 6-8 hours after dosing.
In fact, according to the prescribing information for amoxicillin, around 60% of amoxicillin is excreted in the urine unchanged (i.e. not a metabolite or a byproduct). How your amoxicillin tablets/capsules smell may very much smell like what is being excreted in the urine.
Several Factors Influence Odor
Now there can be several factors that influence whether or not there will be an odor to the urine while taking amoxicillin.
First and foremost, the main factors are food and your hydration status. Food in the stomach inhibits how quickly amoxicillin is absorbed and therefore would greatly reduce a noticeable odor. Additionally, and just as importantly, the amount of liquid intake would also alter the odor of the urine. The more dilute your urine is, the less it will smell.
In addition, and this is a smaller factor, your amoxicillin may also be coming from a different manufacturer than your past medication. Different manufacturers use different inactive ingredients, and while the actual amoxicillin is no different, the other ingredients could certainly influence an odor as well. It would be relatively rare for a drug not to contain the stated amount of active ingredient. When a produced lot from a manufacturer has any flaws, there is an immediate recall issued.
We have checked the recalls for the past few months and amoxicillin has not been recalled. You could certainly check with the pharmacy that dispensed the medication just to be sure.
Final Words
As a practicing pharmacist for many years, I have seen this situation and been asked about it many times before. In all the prior cases I have seen, there has been no reduced effect of the medication. If you are concerned, I would certainly double-check with the pharmacy to make sure everything with the drug is OK and with your doctor but, as mentioned, urine odor is just a potential side effect of amoxicillin therapy.
References & sources
- Amoxil Prescribing Information — AccessFDA
Glossary — Terms in This Answer
- Amoxicillin
- An antibiotic medication used to treat bacterial infections.
- Side effect
- An unintended reaction or consequence that occurs when taking a medication.
- Excreted
- Eliminated or removed from the body, typically through urine or feces.
- Metabolite
- A substance produced when the body breaks down a drug or other chemical.
- Absorbed
- Taken in and passed into the bloodstream from the digestive system.
- Inactive ingredients
- Non-medicinal substances added to a medication to give it form, taste, or stability.
- Active ingredient
- The component in a medication that actually produces the therapeutic effect.
- Recall
- An official request to return and remove a medication from use due to safety or quality problems.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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