Prednisone does not suddenly become ineffective or dangerous if used past its expiration date, but its potency does slowly decrease over time after manufacture. Expired prednisone stored correctly in a cool, dry environment may still retain its full potency for over a year past its expiration date. However, there are no guarantees, and very old prednisone is more likely to have lost potency and thus be less effective. For best results, prednisone should be discarded once expired according to the manufacturer date.
What is prednisone?
Prednisone is a prescription corticosteroid medication used to treat inflammatory conditions like asthma, allergies, arthritis, and ulcerative colitis. It works by reducing inflammation and suppressing the immune system. The drug comes in immediate and delayed release oral tablets of varying strengths, as well as liquid and concentrated solutions. Prednisone is available as a generic drug and under the brand names Prednisone Intensol and Rayos.
How prednisone works
Prednisone is a synthetic corticosteroid similar to the natural steroid hormone cortisol produced in the adrenal glands. It binds to glucocorticoid receptors throughout the body and mimics the action of cortisol. This activates anti-inflammatory and immunosuppressant pathways that work to treat inflammatory disorders.
Specifically, prednisone reduces inflammation by:
- Inhibiting cytokine production and release to prevent inflammation activation
- Reducing macrophage activity to limit inflammation
- Suppressing immune system function by inhibiting leukocyte proliferation and antibody synthesis
- Stabilizing cell membranes and suppressing release of inflammation-producing enzymes
These anti-inflammatory effects make prednisone an effective treatment for diseases like asthma, rheumatoid arthritis, and inflammatory bowel disease that involve inflammation-driven symptoms.
Does prednisone expire?
Yes, prednisone does expire. All medications have an expiration date printed on their packaging that indicates the manufacturer’s recommended timeline for optimal use. For prednisone, this is usually 1 to 2 years from the manufacture date.
The expiration date takes into account the drug’s shelf life and its stability over time in the original packaging. It indicates when the manufacturer expects the product to maintain full 100% labeled potency if stored correctly.
However, expired does not mean the medication immediately becomes unusable or hazardous on the expiration date. Instead, drug expiration dates are very conservative to ensure medications retain their expected strength and quality when used by consumers.
In reality, studies show most medications remain chemically stable and maintain much of their labeled potency and effectiveness for years after the printed expiration date.
Why prednisone expires
Prednisone expires and loses potency over time due to chemical breakdown from factors like:
- Exposure to heat, humidity, and light
- Hydrolysis (breakdown from water)
- Oxidation (reaction with oxygen in air)
- Temperature fluctuations that destabilize chemical bonds
While prednisone tablets are very stable when left untouched, over months to years of storage these destabilizing factors cause the drug concentration to slowly decrease as chemical bonds break down.
This translates to a loss of potency and reduced effectiveness over time past the expiration date. But studies show proper storage can slow this breakdown significantly.
Does expired prednisone still work?
Prednisone that has passed its manufacturer expiration date will still maintain some effectiveness, but its potency slowly declines the longer past the printed expiration date it is used.
How much potency is lost?
Most studies show many drugs in their original containers retain around 90% of their labeled potency for at least 5 years after expiration, as long as they are stored properly at cool temperatures:
- 90% potency retained at least 1 year past expiration
- 80-85% potency retained at least 2 years past expiration
- 70%+ potency retained at least 5 years past expiration
So prednisone tablets stored at room temperature in their original packaging likely maintain close to full potency for around 1 year past their printed expiration date. But after that, potency does gradually decline.
Very old prednisone 5+ years past expiration will have lost significant potency and is more likely to have potency reduced to 50-75% labeled strength depending on storage conditions.
Is expired prednisone safe?
Expired prednisone is generally considered safe to take even years past its printed expiration date. No cases of toxicity from degradation products have been reported with typical prednisone tablets when stored properly.
However, there are some risks to consider when taking very old prednisone:
- Reduced effectiveness from lower potency
- Increased risk of side effects if taking a higher dose to compensate for lost potency
- Greater instability if improperly stored in heat/moisture
So while expired prednisone left in less than ideal conditions for many years does degrade, it does not appear to form toxic substances that create a safety hazard themselves when degraded.
Does prednisone ever become toxic when expired?
There are no reports in the medical literature of prednisone tablets becoming toxic or dangerous after expiration. The main concern is reduced effectiveness or unpredictable potency.
However, one rare exception is prednisone liquid solutions, which some studies show can form the toxic degradation product benzyl alcohol when expired, especially in very old opened containers exposed to heat and humidity.
So there may be greater safety risks taking expired liquid prednisone products. But standard prednisone tablets show good stability.
How to take expired prednisone
Expired prednisone tablets may still offer relief of symptoms if you follow certain precautions:
- Take only properly stored tablets in original packaging
- Check tablets for any damage/discoloration
- Discuss using expired medicine with your doctor first
- Monitor condition closely for desired therapeutic effect
- Adjust dose if response is weaker than expected
Again, contact your physician before taking any expired medication and discontinue use if you experience any suboptimal response or side effects.
Your doctor can work with you to determine if trying properly stored expired prednisone is an option for your situation.
Does prednisone expire faster after opening?
Prednisone tablets inside a sealed and undamaged manufacturer’s bottle generally retain full potency for years past the marked expiration date when stored correctly.
However, any medication expires faster and loses potency quicker once opened. This exposes the tablets to more air, humidity, and temperature fluctuations.
An opened bottle of prednisone will lose potency quicker than unopened. But prednisone tablets are still reasonably stable, so opened prednisone stored properly will likely retain close to full labeled potency for 6-12 months.
Opened prednisone expiration guidelines
Once opened, prednisone tablets follow these general potency expiration guidelines:
- Within 3-4 months: Full potency
- 6 months: Around 90% potency
- 12 months: 80%+ potency
- 24 months: 50-75% potency
So while opened prednisone expires faster, it still maintains most of its labeled potency for about 1 year if kept in a cool, dry environment.
How to store prednisone
To extend the shelf life of prednisone tablets either sealed or opened, it’s ideal to store them as directed:
- In original container and packaging
- At controlled room temperature below 86°F/30°C
- Away from excess heat, humidity, and bright light
- With container tightly closed to minimize air exposure
Avoid storing in warm, moist places like bathrooms where heat and humidity can accelerate chemical breakdown.
Refrigeration can extend shelf life slightly but is not required. Simply storing tablets in a cool, dry indoor environment optimizes stability.
Also keep medications out of reach of children and pets in a locked cabinet.
Can you freeze prednisone tablets?
Freezing is not necessary for prednisone tablets, which are formulated to be very stable at controlled room temperature. The maker of Deltasone brand prednisone says freezing temperatures of 5°F (-15°C) may damage tablets.
However, one study showed prednisone tablets stored continuously frozen at -4°F (-20°C) for up to 1 year maintained 100% labeled potency. But freezing is still not required or recommended by the manufacturer for stable room temperature storage.
Signs prednisone has expired
Carefully inspect prednisone tablets before use for these signs of expired medication:
- Tablets are damaged, cracked, or crumbling
- Tablets are discolored or faded
- Bottles have an unusual odor
- Medicine tastes expired or oddly bitter
- Solution contains sediment or particles
Discard prednisone immediately if you notice any odd textures, smells, or colors that indicate it may be unstable or expired.
Do not take prednisone past its expiration date if stored improperly in very hot or humid conditions that accelerate degradation. Only use expired medication stored under the recommended cool, dry conditions.
Disposing of expired prednisone
To safely dispose of expired or leftover prednisone, follow these steps:
- Take any remaining tablets out of the original containers
- Mix tablets with an undesirable, nontoxic substance like cat litter or coffee grounds
- Seal prednisone and substance mixture in an airtight plastic bag
- Throw bag in household trash collection, NOT down the drain
You can also check for local pharmaceutical take-back programs that collect unused medications like prednisone for proper disposal.
Flushing expired medications down the drain or toilet may contaminate water supplies. Instead, render them undesirable and dispose of properly in the trash.
Can you take prednisone that expired 10 years ago?
Prednisone that is 10 years past its expiration date will have lost most of its original potency and is not recommended for use. Very old prednisone tablets more than 5 years expired maintained only around 65% labeled potency when stored in heat-sealed containers at room temperature in one study. Tablets 10 years expired are unlikely to retain enough strength to provide much therapeutic effect.
Does the expiration date on prednisone matter?
The manufacturer expiration date on prednisone packaging indicates the timeframe the medication is expected to retain full potency. While not a hard cutoff for usability, the date is a helpful guide for when prednisone is optimized for use. Taking prednisone soon before or not long after its expiration date ensures you get its full labeled potency and expected effects.
Can you take prednisone if it expired 2 years ago?
Prednisone tablets stored properly at room temperature typically retain around 90% of their original potency for at least 1 year past their expiration date and around 80-85% potency for 2 years past expiration. So prednisone expired 2 years ago will likely still offer close to its full effectiveness. However, discuss using it with your doctor first, closely monitor your condition, and adjust the dosage if its effects seem weaker than normal.
Does prednisone stop working after expiration?
Prednisone does not suddenly stop working after its expiration date. However, the medication does slowly lose potency over time as the drug molecules break down. While expired prednisone becomes less effective due to declining strength, it does not abruptly become useless or inert immediately after the expiration date if properly stored. Its effectiveness slowly wanes over months to years past the printed expiration.
Can you take expired prednisone for gout?
There’s no evidence using properly stored expired prednisone tablets for a gout flare is unsafe. However, their reduced potency may make the medication less effective for reducing gout inflammation and pain. Discuss trying expired prednisone with your doctor first, closely monitor for desired effects, and adjust your dosage if it seems weaker than normal. Combining expired prednisone with other medicines may provide sufficient relief for gout flares.
The bottom line
While prednisone does expire, tablets stored correctly in their original packaging at controlled room temperature maintain close to full potency for around 1 year past their labeled expiration date. After that, the drug slowly loses potency but does not abruptly become toxic or dangerous.
Before taking expired prednisone, discuss it with your doctor, closely monitor your condition after taking it, and adjust the dose if its effects seem weaker than normal. While expired prednisone stored properly is generally considered safe, using it is a case-by-case decision that your physician can help you make.