Hydroxy Pam is an antihistamine. It is also used to treat high blood pressure. Not only is it not a "powerful sedative" it is not a benzodiazepine. It is very commonly used as a non-addictive drug for anxiety as well. It does sedate some people, but it is certainly not powerful as the show states.
The song Sundown by Gordon Lightfoot is played here. His song If You Could Read My Mind is played in Mato (No. 66) (2016). The lyrics of both songs have relevance to each plot.
Brimley calls Meera "a tough little Punjab." While Parminder Nagra was born in London, she's the daughter of Punjabi immigrants, making the descriptor pretty on-point.