COLCHICINE

Colchicine has been proposed as a treatment for amyloidosis in animals. It has been used in man to prevent amyloidosis in Familial Mediterranean Fever. It apparently blocks the synthesis and secretion of serum amyloid A (an acute -phase reactant protein) by the liver thereby preventing the formation of amyloid-enhancing factor and preventing amyloid deposition. To be effective it must be given early in the course of the disease and it will be ineffective once kidney failure has occurred.

Effects of colchicine:

1. Increases collagenase activity.
2. Anti-inflammatory by decreasing leukocyte migration.
3. Potent inhibitor of cellular mitosis.
4. Prevents many cellular functions such as degranulation, chemotaxsis and mitosis.
5. It appears to block crystal-induced IL-1 generation upstream of inflammasome activation. It is probably useful in autoinflammatory diseases because it blocks IL-1 production caused by NALP3 mutations.
6. Colchicine is able to restore impaired endotoxin homologous tolerance induction via an increase in IL-4 synthesis by monocytes in the period of remission.
7. Colchicine is able to inhibit the periodic changes in monocyte and neutrophil activation to endotoxin, which are associated with the episodic nature of FSF
8. IL-4 stimulates the induction of a monocyte hyporesponsive state in FSF. Colchicine is able to increase IL-4 synthesis in FMF monocytes.

Colchicine should be used with caution in geriatric or debilitated animals. It should be used in during pregnancy only when its potential benefits outweigh its risks. Colchicine can cause nausea, vomiting and diarrhea in dogs. It may also cause abdominal pain and loss of appetite. Prolonged administration has caused bone marrow depression in people. Concurrent use with non-steroidal anti-inflammatory agents is not recommended.

I use 0.6mg. (1 tablet) twice a day in Shar-Pei with FSF, littermates with FSF or in lines with amyloidosis. If problems develop on colchicines therapy I stop the drug for a few days and then reinstitute therapy using a once a day dose or use half the dose twice a day. Once dogs become acclimated to the drug I try going with the full dose. Some Shar-Pei do not tolerate colchicine and can't be on the drug. Also colchicine is used as a potential preventive for amyloidosis. It may or may not have an effect on the frequency or severity of the fever episodes.