Over the years, we have received many reports and have written about errors involving powdered medicines that are not mixed with water before being dispensed from the pharmacy. A recent report reminded us that this error still occurs. So, we thought we would share examples of this error again and then provide recommendations to help prevent these errors from happening.
There are a number of medicines, including many prescribed for children, which come in a powder form. Water must be added to the powder so the medicine can be easily measured and taken. The amount of water used to mix the powder must be precise, so that the prescribed amount of the final liquid mixture provides the correct dose (milligrams [mg]) of medicine per milliliter (mL). It is best for the pharmacist to add water right before the medicine is picked up. In addition, once the powder is mixed with water, the medicine often needs to be refrigerated to stay potent. But if the pharmacist forgets to add the water, or if the wrong amount of water is added at home, a serious dosing error can occur. Below are a few examples of errors that were caught before the medicine was given incorrectly, as well as errors that resulted in harm.
A woman went to give her child a dose of medicine that was prescribed to treat her child’s ear infection. However, the medicine was not in a liquid form as she expected; it was powder. Earlier she had picked up the prescription for the antibiotic Augmentin (amoxicillin and clavulanate) from the pharmacy. Unfortunately, water was not added to the powdered medicine before it was given to her. When she attempted to give her child the first dose and opened the container, she realized the mistake. Fortunately, she returned the medicine to the pharmacy so it could be mixed appropriately, and no harm occurred.
In another case, a pharmacist dispensed a carton containing a bottle of azithromycin powder (an antibiotic) for a child without adding water first. The pharmacist checked the label on the carton to make sure it was the right medicine for the right patient. But she did not open the carton to look at the bottle. So, she did not notice that the powdered medicine had not been diluted with water. Thankfully, the mother returned the medicine to the pharmacy so the proper amount of water could be added before giving any of the medicine to her child.
A serious error occurred when a pharmacist forgot to add water to amoxicillin powder (an antibiotic). The directions said to give 9 mL of medicine for each dose. The child’s father did not realize the medicine should have been a liquid and not a powder. So, the child’s father filled a measuring cup, that came with the medicine, with enough powder to reach the 9 mL line. He gave the powdered medicine to his son with just a little water to swallow it. The child received 20 times more medicine than the doctor prescribed.
Sometimes, parents have assumed they need to add the water to the bottle of powdered medicine. In these cases, they may add too little or too much water and then follow the directions by giving their child carefully measured doses. The problem here is that the amount of water added to the bottle determines how much medicine (mg) is in each dose (mL). So, giving 5 mL of the medicine when only a small amount of water is mixed with the powder will provide a much higher dose than giving 5 mL of the medicine when the proper amount of water is mixed with the powder. The amount of water added to the powdered medicine must be exact and should be added by a pharmacist.
Here’s what you can do: Here are some clues that indicate the pharmacist has forgotten to add the water to a powdered medicine:
- You expect a liquid medicine, but you received a powdered medicine.
- The medicine is a powder with directions to measure the dose in mL. This measure (mL) is only used for liquid medicines.
- The medicine is a powder, but the label on the container describes the medicine as a flavored (e.g., orange flavored) or colored (e.g., pink) liquid.
When picking up a prescription, open the bag and read the label. If you expect a liquid medicine, shake the bottle to make sure it contains a liquid. Never try to add water to a powdered medicine yourself. Bring it back to the pharmacy to have it mixed. The amount of water used must be carefully measured to be sure that each dose has the correct amount of medicine in it. Always double check with your pharmacist before taking or giving medicine if it is a powder. Always use the dosing cup that comes with the medicine. Review with the pharmacist how to measure the medicine using the dosing cup.