Answer
The answer to whether or not it is safe to use expired gabapentin is a little more complicated than a simple "yes" or "no" answer.
There is no data to suggest that gabapentin 'goes bad' or becomes dangerous to take after it is expired, but it certainly may not be as potent as it once was, and thus, may be less effective.
As a rule of thumb, it is advised that you NOT take expired medication, especially if it is not an emergency.
As your gabapentin states an expiration date of 2016, the medication should be disposed of as there is a chance that it won't have the required efficacy needed. If you are in need of another prescription, please reach out to your doctor.
Expiration Date And Drug Potency
In the United States, the law mandates that at the time of expiration,a drug must be at least 90% of its original potency. That is our concern when we look at a drug's expiration date...is it as effective as it once was (when it was originally manufactured and kept under normal storage conditions)?
Very rarely is safety a huge concern with expired medications as it is uncommon that medications will "go bad" to the point of causing illness. Some medications are rarely associated with this (e.g. tetracycline), but gabapentin is not. Again, it just may not be as strong as it once was.
When Does Gabapentin Expire?
Most drugs, labeled in original bottles, will expire two to five years from the date of manufacture.This holds true for gabapentin.
A company will often perform stability tests for a finite time period. For example, if a manufacturer wants to set an expiration date at 3 years, they perform tests on the drug up to and including that time period, but not beyond. The drug may very well still be within the acceptable potency range beyond that date, but there is no data to verify.
In other words, the date on a manufacturer's bottle is an assurance to a pharmacy (and customer) that the drug will maintain its potency until AT LEAST the listed expiration date when stored under ideal storage conditions.
Interestingly enough, some studies show that drugs will maintain 90% of their potency for a minimum of 5 years after their expiration date! The problem is that afterthe listed expiration date, there just may not be data to go off of to determine if a drug is still at the labeled potency.
Listing The Expiration Date
In a retail setting, most states don't require the prescription bottle to list the expiration date of the drug from the 'stock' bottle. This is mostly due to two factors:
- It is too cumbersome to record the manufacturer expiration date of every fill of medication. Most pharmacy software isn't at the point where this is possible. In the future, however, enhanced bar code scanning may make this a possibility.
- The storage conditions of dispensed medications are often not ideal. Very often they are left at too high or too low of a temperature, are not stored in an airtight container, or are stored in humid conditions (e.g. the bathroom).
Due to the above reasons, many states simply require a listing of an expiration date of one year after dispensing, even if the manufacturer's bottle states a later date.So your bottle of gabapentin 100mg may have had an expiration date of 2017 or 2018, but the dispensed bottle may list 2016.
Factors That Influence Drug Expiration
One of the most important factors in the stability of drugs is how they are stored. Factors that can affect the stability and efficacy of medications are light, air, moisture, and temperatures (too hot or too cold). How do the tablets/capsules look? Do they appear wet in nature? Do they still look solid in form or are they crumbling? Are they in the air-tight container they were dispensed in? Do they have an unusual odor? For many drugs, even if there are no signs the drug has degraded, there really is no way to definitively tell once the expiration date had passed.
In regard to gabapentin specifically, it is a capsule dosage form, which is considered one of the most stable dosage forms post-expiration date. Liquids (like reconstituted antibiotic suspensions) are not considered stable at all and should not be used post-expiration date.
What Is Gabapentin?
Gabapentin is an anti-convulsant that works directly on nerves. It affects chemicals and nerves in the body to treat seizures and certain types of pain like nerve pain like diabetic neuropathy or post-herpetic pain caused by the herpes or shingles virus (herpes zoster). Gabapentin also is used to treat restless leg syndrome and seizures in those at least 3 years old. Gabapentin is likely to cause dizziness and drowsiness.
Final Words
Thank you for reaching out to us and please do so again when another question comes to mind!
