Many cases of nasolacrimal duct
obstruction will clear on their own with massage
over the lacrimal sac and time. Topical drops my provide partial control of the infections that inevitably occur due to lack of flow within the lacrimal sac, which normally drains into the nose.
Ultimately, probing may need to be accomplished to open the lacrimal sac in the nose. You can use the medicine as prescribed, but the effect will be limited.