misdosing

Misdosing occurs when a drug is given in an incorrect amount, at the wrong time, via the wrong route, or with an inappropriate dosing frequency. It includes underdosing, overdosing, and dosing errors that arise from miscalculation, misinterpretation of concentration, or miscommunication. Misdosing is a type of medication error that can occur at any point in the medication-use process, including prescribing, transcribing, dispensing, and administration.

Common causes include calculation mistakes, unit confusion (such as milligrams versus milliliters), decimal point errors, and confusion between similar drug names. Other contributing factors are incorrect use of dosing devices, outdated or misread concentrations, illegible handwriting, interruptions during administration, and language or literacy barriers. High-stress environments, complex regimens, and polypharmacy can also increase the risk.

High-risk contexts include pediatrics and geriatrics, where dosing often depends on weight or renal function, and settings with high-alert medications such as insulin, anticoagulants, opioids, and chemotherapeutics. Misdosing can occur in hospitals, clinics, pharmacies, or at home, and may affect single or multiple doses.

Prevention relies on system-level safeguards. These include double-check practices for high-risk doses, computerized physician order entry with decision support, bar-code or smart-pump technology for IV medications, standardized dosing charts, and readily accessible dosing calculators. Clear labeling, appropriate unit presentation, and proper medication preparation reduce confusion. Pharmacist verification, good communication, and patient or caregiver education also help prevent misdosing.

Consequences range from therapeutic failure and treatment delays to toxicity and serious adverse events, potentially leading to hospitalization or death. Misdosing is largely preventable through careful processes, staff training, and robust medication safety culture.