Resolved: Subset rows of data that contain a specific string over several columns

df <- data.frame(id = paste0("ID",1:10),
             Medication1= c("paracetamol", "ibuprofen", "opiate", "sertraline"),
             Medication2= c("Lipitor", "ketamine", "zoloft", "xanax"),
             Medication3= c("ibuprofen", "paracetamol", "Zocor", "Zestril"),
             other= LETTERS[1:10])

df[rowSums(df == 'paracetamol') > 0, ]
#    id Medication1 Medication2 Medication3 other
# 1 ID1 paracetamol     Lipitor   ibuprofen     A
# 2 ID2   ibuprofen    ketamine paracetamol     B

df <- structure(list(id = c("ID1", "ID2", "ID3", "ID4"), Medication1 = c("paracetamol", 
"ibuprofen", "opiate", "sertraline"), Medication2 = c("Lipitor", 
"ketamine", "zoloft", "xanax"), Medication3 = c("ibuprofen", 
"paracetamol", "Zocor", "Zestril"), other = c("A", "B", "C", 
"D")), class = "data.frame", row.names = c(NA, -4L))