Python-Pandas-Dataframe - Remove only first few numbers from string

I want to extract the number before the text begins

column1
10units
200 mg
4000units/40mg
40 units

The below code worked for all cells except for the cell that had multiple numbers

df['newcolumn'] = df['column1'].astype('str').str.extractall('(\d+)').unstack().fillna('').sum(axis=1).astype(int)

The output looks like below

    newcolumn
    10
    200
    400040
    40

Expected output

 newcolumn
        10
        200
        4000
        40