<unk> , also known as colcemid, is a drug used in chemotherapy.It is closely related to the natural alkaloid colchicine with the replacement of the acetyl group on the amino moiety with methyl, but it is less toxic. It depolymerises microtubules and limits microtubule formation (inactivates spindle fibre formation), thus arresting cells in metaphase and allowing cell harvest and karyotyping to be performed.
During cell division<unk>  inhibits mitosis at metaphase by inhibiting spindle formation. Medically<unk>  has been used to improve the results of cancer radiotherapy by synchronising tumour cells at metaphase, the radiosensitive stage of the cell cycle. 
In animal cloning procedures<unk>  makes an ovum eject its nucleus, creating space for insertion of a new nucleus.
Demecolcine
Diisopromine
Clofoctol
Lerisetron
Avacopan
Glycopyrronium bromide
Levomepromazine
Dolastetron 