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Dosing devices: beware of dosing errors

Taking certain precautions helps avoid errors related to dosing devices for oral medication.

Drugs in liquid form are useful for administering medication to a child or a person who has difficulty swallowing tablets or capsules.

As for all treatments, the dose administered is a major factor in the harm-benefit balance. Liquid forms are often presented in a bottle containing several doses, and precise delivery requires a dosing device: a measuring spoon, dropper, oral syringe, measuring cup, etc. Particular attention should be paid to this dosing device in order to prevent dosing errors.

The use of household spoons (teaspoons or dessert spoons) for measuring out doses should be avoided, as their capacity varies too much from one design to another.

Droppers allow for precise but limited measuring, but are not reliable if large numbers of drops are required. They can be imprecise if too much pressure is applied to the bulb, or if they are not held vertically.

Graduated dosing devices sometimes cause errors. The graduations vary from one system to another (millilitres, milligrams, drops, the patient’s weight in kilograms). Some are designed to administer a fixed dose, with no possibility of adjustment and with no mention of the actual quantity administered. The drug’s name is rarely visible on these devices, which can result in confusion between drugs and in dosing errors.

Measuring cups often have a disproportionate capacity, greater than the maximum recommended dose.

When a dosing device is required, it is better to take the time to prevent any errors that may be associated with its use: read the instructions on the dosing device carefully; double-check the dose to be administered; keep the medicine in its original packaging together with the dosing device and patient information leaflet; avoid handling two drugs at the same time.

©Prescrire 1 August 2011

"Dispositifs doseurs : pour éviter les erreurs de doses" Rev Prescrire 2011; 31 (334): 580-581.

For more information:

Contents of  the special
issue of La Revue Prescrire
"Affections du quotidien -
Retenir les traitements utiles,
sans ou avec médicaments"