Siri specifically keeps getting activated by pharmaceutical tv commercials

Change your activation word to "Hey Siri". That will prevent inadvertent activations when it hears words such as "Seriously", with an emphasis on "SIRIously", or "Shirley"., or "Cereal" The same inadvertent activations are noted on Alexa devices when a family member has a person named "Alexis" or it hears that word on TV.

You can also turn off voice activated Siri completely.