Welcome to HM .
Your father has mild hypertension;with diabetes
& heart problem;as it seems from the medicine he is taking.As you said he has spondilysis & because of that probably neurological problem for which he has been prescribed pregabilin with mecobalamine.These formulations are nerve
healers & are beneficial to people with nerve problems especially methylcobalamine;so he can take it .As for drug interaction
they are like multivitamins so they don't interact much .Your father can easily take it.
wish him good health .