Certain prescriptions, such as antibiotics prescribed for an infection, should be given as directed and given until the prescription is gone. Other medications are prescribed with more of a "use as needed" administration schedule. If there is ever a question about a prescription drug; possible side effects, storage and handling, administration, etc., you should discuss directly with your veterinarian and as soon as the question arises.
Every animal and every medication is different. There is no universal "rule" on how long a product will last, or if it will still be OK to use after the expiration date printed on the packaging. General safe storage tips include, but are not limited to:
- Keep out of direct sunlight
- Keep at room temperature (or possibly refrigerated - check package)
- Keep dry - high humidity may cause deterioration in some products
Drugs are often expensive, and it may be tempting to save money by using an expired product, but consider if it were food -- would you serve food that is days/weeks/months/years after the expiration date? Besides losing strength and effectiveness, the expired item may become toxic over time (bacterial or mold growth, degradation of chemical components) and that would create more problems that it would solve.
Safe disposal of medications It is not a good idea to dispose of medications in trash designated for a landfill or flush them down a toilet. This pollutes landfill, and may contaminate ground water and wildlife.
A good first place to start would be to check with your veterinarian or local (human) pharmacy to see what safe disposal options there are for expired drugs in your community. Check too with your city waste disposal department; some municipalities offer incineration to safely dispose of expired drugs.
