A package includes an outer sleeve and a slider for holding a blister pack slidably mounted within the outer sleeve. The outer sleeve has a locking edge. The slider has a locking flap extending in a direction away from the closed end of the outer sleeve for engagement with the wall of the outer sleeve. The flap has a free edge which provides a pair of locking edges for engagement with the locking edge of the outer sleeve wall. The outer sleeve has a release button which may be pressed to deflect the slider flap away from the wall of the outer sleeve and enable the free edge of the slider flap to slide past the locking edge to allow the slider to be withdrawn from the outer sleeve.