Certain medications have a narrow therapeutic index, that is the margin of safety and toxicity is close. Hence, little decreases in the pharmacological activity can result in severe consequences for patients. Observing the expiration date is obligatory for the following medications:
- Anticonvulsants such as carbamazepine – narrow therapeutic index
- Dilantin, phenobarbital – very quickly lose potency
- Nitroglycerin – very quickly lose potency
- Warfarin – narrow therapeutic index
- Procan SR – sustained release procainamide
- Theophylline – very quickly lose potency
- Digoxin – narrow therapeutic index
- Thyroid preparations
- Oral contraceptives
- Epinephrine – very quickly lose potency
- Insulin – very quickly lose potency
- Eye drops – eyes are particularly sensitive to any bacteria that might grow in a solution once a preservative degrades.
Note: Long-expired antibiotics can contribute to increased antibiotic resistance and treatment failure and should never be used.