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Tricky Dosing for an Important COVID-19 Medicine

Published October 26, 2022

Paxlovid (nirmatrelvir and ritonavir) is a medicine used to treat people with mild-to-moderate coronavirus disease 2019 (COVID-19). It is prescribed when someone tests positive for the virus and is at high risk for developing a severe case that may lead to hospitalization or even death.

Once Paxlovid is prescribed, the person needs to take it twice a day for 5 days. For people who do not have kidney disease, each regular dose of Paxlovid consists of three tablets: <u>2 tablets</u> of nirmatrelvir and <u>1 tablet</U> of ritonavir. The morning and evening doses are packaged together on a blister card that holds all six tablets (Figure 1). The pharmacy will give you a carton that has five blister cards, one for each of the 5 days of treatment.

Figure 1. This blister card contains two regular doses of Paxlovid. Each morning and evening dose consists of 2 tablets of nirmatrelvir and 1 tablet of ritonavir.

For people with kidney disease, each morning and evening dose of Paxlovid is reduced to 1 tablet of nirmatrelvir and 1 tablet of ritonavir. A special blister card is now available that provides this reduced number of tablets per dose (Figure 2). For each dose, the area on the blister cards where the second nirmatrelvir tablet is missing is labeled “Tablet cavity intentionally left empty.”

Paxlovid is an important medicine for treating COVID-19. However, because it requires taking multiple tablets, the packaging and dosing can be very confusing for both healthcare providers and people who need to take the medicine. For example, some people have accidentally taken the wrong tablets, some have taken only one tablet at a time, and others have taken all the tablets on the blister card at one time. In some cases, the pharmacy may only carry a blister pack for the regular dosing and not the reduced blister pack for those with kidney disease. If this happens, the pharmacist will need to remove one nirmatrelvir tablet from each dose of the blister cards. The pharmacist should then apply a label to the spaces where the tablets were removed indicating they were intentionally removed. There have been some cases in which the pharmacist forgot to remove the nirmatrelvir tablets on one or more of the blister cards, or removed the wrong tablets (ritonavir) from the blister cards.

Figure 2. For people with kidney disease, a reduced dose of Paxlovid is needed. For each morning and evening dose, this blister card contains 1 tablet of nirmatrelvir and 1 tablet of ritonavir.

Here’s what you can do: Ask to speak with your pharmacist when picking up your prescription for Paxlovid. Open the package and ask the pharmacist to explain how to take a dose of medicine. If you have kidney disease, make sure your pharmacist is aware. Ask your pharmacist to print out a Fact Sheet and review it with you if you don’t already have one. Or, if you have a copy of it, bring it with you so you can ask questions. The Fact Sheet includes important information about Paxlovid such as how to take the medicine, possible side effects, what to do if you miss a dose, and what to do if you are pregnant or breastfeeding. The Fact Sheet also has important information about other medicines that might interact with Paxlovid. Before you start taking Paxlovid, be sure to review the list of medicines on the Fact Sheet and let your pharmacist and doctor know if you currently take any of the medicines on the list.

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