Your husband may need a beta-blocker medication to go along with the nifedipine - do not discontinue any cardiac meds cold-turkey, talk to the prescribing physician first!
Stopping cardiac medications without medical supervision can cause severe rebound effects (migraines are common) and can furthur strain liver and kidney functions, as well as increasing stroke/cardiovascular risks.
Also discuss any herbal supplements before starting them as they may interfere with current/future prescriptions.