Create duplicate rows with alternating column values.

If I'm understanding the broader context of your question correctly, then I think a different approach is worth considering. The key is unpivoting your count columns. If you unpivot those columns, you'll get a row for each method.

Before:

After:

Then you can rename the drug based on the method. You can pivot again at the end if you want, but it might be better to keep the rows unpivoted (it may make writing DAX measures easier).

Here's the example above you can paste into the Advanced Editor of a new Blank Query to look at the steps in more detail:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WCvF3CnJU0lEy1DfUNzIwMgQygzwcnYCUAUgUTMfqRCuFOfo5+2NVZwJVawZW5xjlGeIRBFJphNVEIyA2Bqt09vH0cwFZbYyh0BChMBYA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Drug = _t, Date = _t, Location = _t, Enteral = _t, Inhaled = _t, Parenteral = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Drug", type text}, {"Date", type date}, {"Enteral", Int64.Type}, {"Inhaled", Int64.Type}, {"Parenteral", Int64.Type}}),
    #"Unpivoted Columns" = Table.Unpivot(#"Changed Type", {"Enteral", "Inhaled", "Parenteral"}, "Method", "Count"),
    #"Filtered Rows" = Table.SelectRows(#"Unpivoted Columns", each ([Count] <> 0)),
    #"Replaced Value" = Table.ReplaceValue(#"Filtered Rows",each [Drug], each if [Method] = "Parenteral" then "IV " & [Drug] else [Drug], Replacer.ReplaceText, {"Drug"}),
    #"Pivoted Column" = Table.Pivot(#"Replaced Value", List.Distinct(#"Replaced Value"[Method]), "Method", "Count", List.Sum)
in
    #"Pivoted Column"

Final output:

 To use this on your own data, replace my first two steps (Source and #"Changed Type") with whatever your data source is, update the table reference in #"Unpivoted Columns" to match whatever the name of the last step in your query is, and update the actual column names in your query or the column name references in my new part of the query to match.