If a cat vomits a considerable amount of time after taking medication, and the medication itself has a long half-life and high bioavailability, then the medication has likely already been absorbed and has taken effect. In this case, vomiting has a relatively small impact on the efficacy of the medication.
However, if a cat vomits immediately or shortly after taking medication, the medication may not have been fully absorbed, and vomiting in this case may affect its efficacy. Furthermore, if the medication itself is highly irritating to the gastric mucosa, it may also cause the cat to vomit, thus affecting the absorption and effectiveness of the medication.
