Med Tox Flashcards
What are the main 3A4 inhibitors known to interact with colchicine?
Clarithrimycin, erythromycin, ketoconazole, and grapefruit juice.
Colchicine given with statins has reportedly caused what adverse effect?
Myopathy
What is the mechanism of toxicity for colchicine?
Colchicine binds to the I traveller protein tubulin preventing polymerization to form microtubules resulting in impaired protein assembly. In toxic doses colchicine arrests mitosis in metaphase because chromosome separation depends on microtubule function.
Which systems are most affected by colchicine toxicity and why?
The systems with the highest turnover of cells: bone marrow, GI, hair follicles
What is the rate of oligospermia due to colchicine?
0-37%
Can women breast feed if taking colchicine?
Yes. American Academy Peds categorizes colchicine as compatible with breast feeding
What is the first phase of colchicine poisoning?
GI phase.
What is the second phase of colchicine poisoning?
Multi-organ phase.
What is the third phase of colchicine poisoning?
Surviving pts only.
What is the usual cause of death in colchicine poisoning?
Death from acute poisoning is usually due to hemodynamics collapse and cardiac arrhythmias or infectious or hemorrhagic complications typically 24-36 hrs after ingestion or it could be sudden.
Which CYP metabolizes colchicine?
3A4
Following recovery from colchicine poisoning what are common sequelae?
Myopathy, neuropathy, proximal limb weakness, distal sensory abnormalities, distal areflexia, nerve conduction impairment consistent with atonal neuropathy. In addition a rare TEN reaction has been reported.
What characterizes chronic colchicine poisoning?
Neuromyopathy( with proximal weakness)- increased CPK is invariable- and cardiac failure.
What plants are often mistaken for C. autumnale and G superba?
Wild garlic, wild sweat potato
What is the colchicine toxidrome?
Gastroenteritis, hypotension, lactic acidosis and prerenal azotemia
