Colchicine
An autumn crocus alkaloid that blocks microtubules in white blood cells, used for gout flares and familial Mediterranean fever.
Drug card
- How it works
- Binding tubulin so neutrophils cannot migrate into inflamed joints
- Used for
- Treating and preventing gout flares
- Familial Mediterranean fever
- Known for
- Diarrhea
- Bone marrow suppression
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does colchicine work?
Colchicine, an alkaloid from Colchicum autumnale, binds beta-tubulin and blocks microtubule assembly, so neutrophils are not activated and do not reach the joint or degranulate. It may also hinder inflammasome assembly and interleukin-1β activation. CYP3A4 and P-glycoprotein clear it, which explains its dangerous interactions.
Uses
What is colchicine used for?
- Treating and preventing gout flares
- Familial Mediterranean fever
Side effects
Side effects of colchicine
- DiarrheaKnown for
- Bone marrow suppressionKnown forSerious
- Nausea and vomiting
- Abdominal pain and cramps
- Aplastic anemiaSerious
- Muscle pain and weakness (myopathy)
- Rhabdomyolysis, especially with statinsSerious
- Nerve damage (sensorimotor neuropathy)Serious
- Hair loss
- Reduced sperm count
- Severe allergic reactions (anaphylaxis)Serious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- In kidney or liver impairment, P-gp or strong CYP3A4 inhibitors are contraindicated with it: fatal toxicity has followed usual doses.
- Statins, fibrates and digoxin taken alongside raise the risk of muscle damage and rhabdomyolysis.
- Severe diarrhea or vomiting can herald toxicity, so the dose is reduced or stopped.
- Fatal overdoses occur, in adults and in children who swallow tablets.
Good to know: It does not lower uric acid; it is given alongside allopurinol or febuxostat to prevent the flares that come when they are started.
Remember it
A way to remember it
Colchicine calms the fight over the crystals but leaves the uric acid alone.
By blocking microtubules it stops neutrophils from swarming urate crystals, which eases a flare, but uric acid levels do not change. Diarrhea is the early warning of toxicity.
Written for biofideX
Its class
Colchicine
Colchicine binds tubulin and stops it polymerizing into microtubules. Without working microtubules, neutrophils cannot be activated, release their granules or migrate to the urate crystals in a joint, so the inflammation of gout settles. It may also disrupt the inflammasome that activates interleukin-1β. It does not change uric acid levels.
Easily mixed up with xanthine oxidase inhibitors, non-steroidal anti-inflammatory drugs and vinca alkaloids.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Colchicine tablets: label (DailyMed)
- Colchicine (NCI Thesaurus)
- Colchicine (NHS)
- Allopurinol tablets: label (DailyMed)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Pain, fever and inflammation
Colchicine is one of 15 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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