tetracycline(in) + H(+)(out) = tetracycline(out) + H(+)(in)
tetracycline(in) + h(+)(out) = tetracycline(out) + h(+)(in)
tetracycline(in) + H(+)(out) = tetracycline(out) + H(+)(in)
tetracycline(in) + h(+)(out) = tetracycline(out) + h(+)(in)