Pharmacoeconomics and Safe Medication Use
An example of nonpreventable ADEs would include drug shortages that affect standard of care.
The norepinephrine shortage in 2011 was found to be associated with a 15% increased risk of
in-hospital mortality.
Adverse drug reactions
Definitions
WHO defines ADRs as “any response to a drug which is noxious and unintended, and which
occurs at doses normally used for prophylaxis, diagnosis, or therapy of disease, or for the
modification of physiological function.”
ii.
drug that is noxious and unintended, and that occurs at doses used in humans for prophylaxis,
diagnosis, or therapy, excluding failure to accomplish the intended purpose.”
iii.
The primary difference between the WHO and Karch and Lasagna ADR definitions is that,
according to the WHO definition, therapeutic failures are an unintended effect and an ADR,
whereas according to the definition by Karch and Lasagna, they are not. Both definitions refer
to doses normally used in humans, which exclude overdoses and medication errors that exceed
normal doses.
iv.
ADRs caused by therapeutic failures with easily retrievable, detailed data that document the
drug and the therapeutic failure can significantly affect patient care.
Examples by definition
WHO
| (a) | Clopidogrel failure to prevent an ischemic stroke |
|---|---|
| (b) | Enoxaparin failure to prevent deep vein thrombosis |
| (c) | Famotidine failure to prevent intravenous ketorolac-induced gastropathy |
| (d) | Pantoprazole failure to prevent GI bleeding from a stress ulcer in a critically ill patient |
ii.
Karch and Lasagna
| (a) | Lorazepam when used to treat anxiety may cause sedation. |
|---|---|
| (1) | This is an unintended adverse reaction; conversely, lorazepam for sedation in a |
critically ill patient is an intended effect, not an ADR.
| (b) | Diphenhydramine causing unintended sedation when used to treat allergic rhinitis |
|---|---|
| (1) | This is an ADR; conversely, diphenhydramine as a sedative hypnotic is an intended |
effect, not an ADR.
For reporting an ADE to the FDA, the FDA defines ADEs as serious adverse events related to drugs
or devices in which “the patient outcome is death, life threatening (real risk of dying), hospitalization
(initial or prolonged), disability (significant, persistent, or permanent), congenital anomaly, or required
intervention to prevent permanent impairment or damage.” FDA-reportable serious ADEs may include
the following:
Acetaminophen-induced hepatotoxicity
Apixaban-induced intracranial hemorrhage
Gentamicin-induced irreversible ototoxicity
have not previously been reported for new or old drugs.
The FDA Adverse Reporting System (FAERS) database is designed as a postmarking surveillance
tool for medications and biologics. Other therapies, such as medical devices, have their own
reporting system.
The CDC and FDA co-sponsor the Vaccine Adverse Event Reporting System (VAERS), which is
focused on identifying potential signals for adverse events associated with vaccines licensed for use
within the United States.