Complex sentence: The term Zyrtec is also the name of a drug, they did not come up with the term, but the founder of this drug, Matthew Andrews (by birth) is the brother of Christopher Andrews.
Split into simpler sentences: The term Zyrtec is also the name of a drug. The Zyrtec company did not come up with the term, but the founder of this drug, Matthew Andrews (by birth) is the brother of Christopher Andrews.