Transmucosal refers to the delivery of a medication across a mucous membrane. In the tactical field setting the two principal locations are the mouth and the nose. We’ll discuss intranasal medication delivery a little later in this module and focus on the routes commonly used in the mouth right now.
Oral transmucosal can refer to delivery through one of three different locations: sublingual, transbuccal, and translingual. All three locations can take advantage of some of the benefits of a transmucosal approach, which include:
Each medication is developed to be optimally delivered based on the site of absorption – under the tongue, against the cheek, or on top of the tongue. Some of this has to do with the pharmacology of the medications, and some to do with practical considerations about administering the medication. If the medications are swallowed, some of the benefits of a transmucosal delivery are lost. The degree of that loss depends on how long the casualty was able to avoid swallowing the medication and even to some extent the amount of time they were able to delay swallowing secretions that might contain some active ingredients from the medication.
In TCCC, the two variations seen in the current guidelines are the transbuccal administration of fentanyl and the translingual delivery of ondansetron.
In the transbuccal administration process, the medication is held between the upper gums and the inside of the cheek. By placing a medication by the upper gums, the stimulation to the salivary glands is reduced and there is less likelihood of the medication being swallowed in the secretions. The effects can be slightly enhanced by alternating from one side to the other or rotating the lozenge, if possible. In the case of the lozenges on a stick (a “lollipop”), the likelihood of swallowing the medication is reduced even further. As with all transmucosal medication delivery, the casualty should not eat or drink while the medication is being administered. The time to complete absorption can vary based on how actively the casualty moves the lozenge from one area to the other in their mouth.
The translingual delivery of a medication is less common and is often done via a spray or mist. But in the case of ondansetron, they have developed a fast-dissolving pill form. Perhaps even more than the transbuccal route of administration, it is difficult for the casualty to avoid swallowing the medication. However, unlike a sublingual route that will always have a significant risk of being diluted by saliva, the top of the tongue can be kept relatively free of secretions until the medication has dissolved using the translingual approach.