Does using cocaine change the shape of your nose?

Yes. Chronic Cocaine use eats away at your septum which can cause complete collapse of the nose. Not a pleasant look!
Absolutely! It shrinks the blood vessels in the septum which slowly melts away allowing the bridge to collapse, essentially destroying the shape of the nose and the ability to breathe through it.
Saddle Nose Deform. End stage use of Cocaine will destroy the vascular supply of the septum (the midline part of the nose dividing the right and left halves of the nose and provding support to the bridge). Eventually the spetum will collapse producing the "saddle nose deformity" which takes on the appearance of a boxer's nose.
Yes. Cocaine is a powerful vasoconstrictor. If enough is exposed to the nasal mucusa, vasoconstriction occurs and can, in extreme cases, cause the cartilage support to necrose (to die). Loosing cartilagenous support will alter the shape of the nose ("Cocaine nose").
Yes. People who use a lot of Cocaine end up destroying the septal cartilage in their nose. This causes the middle of the nose to collapse causing what is called a saddle-nose deformity.