Milliliter-Only Dosing Reduces Liquid Medication Errors

Oral liquid medications are involved in more than 80% of medication errors involving young children and occurring outside of hospitals. Many errors involving oral liquid medications result from mistakes in measuring the right dose, which can be caused by inconsistent dosing instructions and confusion between different units of measurement. One of the most common dosing errors occurs when a patient or caregiver confuses teaspoons and tablespoons, which can result in a threefold dosing error. Including spoon-based units of measure (ie, teaspoons or tablespoons) in dosing instructions may also encourage the inappropriate use of household spoons for dosing medications, which can lead to overdosing or underdosing. 
To prevent dosing errors, use metric units only (ie, milliliters [mL]) in dosing instructions and on dosing devices (eg, oral syringes, dosing cups) for oral liquid medications. Studies have found that parents and caregivers, including those with low health literacy, are familiar with mL units and can accurately dose medications using mL alone, resulting in fewer dosing errors compared with using teaspoons. In a 2019 CDC study on primary care provider (PCP) perceptions and practices, researchers found that only a minority of PCPs believed that patients and caregivers prefer dosing instructions in mL-only, with responses ranging from 23.9% of nurse practitioners to 48.4% of pediatricians. In fact, most PCPs incorrectly responded that patients and caregivers prefer instructions that include spoon-based units alone or together with mL, with 67.9% of PCP respondents holding this belief. As a result, more than half of internists, nurse practitioners, and family medicine physicians, and nearly 40% of pediatricians, reported that they would include spoon-based units (alone or together with mL) in the dosing instructions if they were writing a prescription for an oral liquid medication.
In recent years, many organizations and federal health agencies have issued guidelines and policy statements to promote the use of mL-only dosing instructions and devices for oral liquid medications. In 2021, the American Academy of Pediatrics released a policy statement and toolkit that reviewed the evidence on how medication errors most commonly happen in the home and provided recommendations on ways to prevent them. These recommendations included improving communication with patients and caregivers regarding appropriate dosing units, encouraging the use of standardized dosing tools that are the right size for the prescribed dose of oral liquid medication, and providing continuing education materials for providers. The National Council for Prescription Drug Programs also published updated recommendations and guidance in 2021 to standardize mL as the unit of measure for dosing on prescription container labels of oral liquid medications dispensed from pharmacies. These efforts, along with actions by other organizations, aim to reduce errors that can occur when giving oral liquid medications. 
Clearly and consistently using mL-only markings on liquid medication packaging, labels, and dosing devices (such as oral syringes and dosing cups) can minimize errors when measuring and giving doses. To help reduce medication errors, healthcare professionals can also:
Use mL units when prescribing, labeling, dispensing, and communicating about oral liquid medications.
Use the standard abbreviation “mL” on prescriptions and prescription container labels for oral liquid medications (other abbreviations for milliliter, like “mls” or “cc,” should not be used).
Ensure that dose amounts always use leading zeros before the decimal point (eg, “0.5” mL, NOT “.5” mL) for amounts less than one, and never use trailing zeros after a decimal point (eg, “5” mL, NOT “5.0” mL) on prescriptions or prescription container labels for oral liquid medications.
Encourage the use of standardized dosing tools (such as oral syringes or dosing cups) with all oral liquid medications. Ensure that an appropriate dosing device is in the medicine packaging or provided by the pharmacist or prescribing clinician. Educate parents and other caregivers not to use household spoons to give medications.
Provide a dosing tool with number markings and mL units that correspond with what is printed on the prescription container labeling of oral liquid medications. The dosing tool provided should also be the smallest volume size needed to measure the dose prescribed without having to fill the dosing tool multiple times to administer a single dose.
Review educational materials, including web content and images, to ensure that proper dosing techniques are described and shown.
Use health literacy–informed verbal counseling strategies (eg, plain language, pictures/drawings, and teach back/show back) to educate parents and caregivers on how to give the medication correctly.
Remind parents and caregivers to program the Poison Help number (800-222-1222) in their phones so that they will have it if they need it.
Links to view and download resources:
Protect Your Patients – dosing cupButton: DosingCup-Button285.jpg (285×285) (cdc.gov)Large print: DosingCup-Graphic600.jpg (600×600) (cdc.gov)
Button: DosingCup-Button285.jpg (285×285) (cdc.gov)
Large print: DosingCup-Graphic600.jpg (600×600) (cdc.gov)
Protect Your Patients – Oral syringeButton: OralSyringe-Button285.png (285×285) (cdc.gov)Large print: OralSyringe-Graphic600.png (600×600) (cdc.gov)
Button: OralSyringe-Button285.png (285×285) (cdc.gov)
Large print: OralSyringe-Graphic600.png (600×600) (cdc.gov)
Spoons Are for SoupButton: SpoonsAreForSoup-Button285.png (285×285) (cdc.gov)Large print: SpoonsAreForSoup-Graphic800.png (800×800) (cdc.gov)8.5″ x 14″ Poster: SpoonsAreForSoup-Poster85by14-P.pdf (cdc.gov)
Button: SpoonsAreForSoup-Button285.png (285×285) (cdc.gov)
Large print: SpoonsAreForSoup-Graphic800.png (800×800) (cdc.gov)
8.5″ x 14″ Poster: SpoonsAreForSoup-Poster85by14-P.pdf (cdc.gov)
 
Public Information from the CDC and Medscape