Final answer:
The most likely class of drugs used for treating a persistent cough is antitussives, which are designed to suppress the cough reflex. The efficacy of traditional cough suppressants like codeine is currently debated, and the use of over-the-counter cough medications, especially in children, is not consistently recommended due to a lack of evidence for effectiveness and potential side effects.
Step-by-step explanation:
The class of drugs most likely used for a persistent cough is antitussives. Antitussives are specifically designed to suppress coughing, helping to provide relief from persistent cough symptoms. While codeine was traditionally viewed as the go-to cough suppressant, its effectiveness is now questioned.
Various formulations may also include other substances like expectorants, antihistamines, and decongestants, depending on the type of cough and associated symptoms. However, it is important to note that over-the-counter cough treatments have not been conclusively shown to be effective in treating viral upper respiratory infections and their use, particularly in young children, may not be recommended due to lack of evidence and potential harms.