Exhibits dual functions as a Na(+)(Li(+)/K(+))/H(+) antiporter and a multidrug efflux pump. Catalyzes the efflux of Na(+), Li(+) and K(+) in exchange for external protons. Shows a preference for Na(+), followed by K(+) and Li(+). Can also function as a multidrug efflux pump. Transports ethidium bromide and norfloxacin. Norfloxacin transport is inhibited by CCCP. Optimum pH is 9.0 for Na(+)/H(+) and Li(+)/H(+) antiport activities. Optimum pH is 8.5 for K(+)/H(+) antiport activity. Belongs to the major facilitator superfamily.