Colchicine

Microtubule Inhibitor·Musculoskeletal & Rheumatology

Acute gout flares, gout prophylaxis, Familial Mediterranean Fever

PBSANTI-INFLAMMATORYLengout, Colgout0.5 mg tabletS4+1

Max Dose

1.5 mg/day (Acute)

Half-life

27-31 h

Diarrhea

TOXICITY SIGN

Renal Adj.

MANDATORY

Rapid Summary

Overview

Ancient alkaloid derived from the autumn crocus. Highly specific anti-inflammatory for gout, acting as a direct mitotic/microtubule poison to neutrophils.

Maximum Dose

Max 1.5 mg on Day 1 for acute gout (e.g., 1 mg STAT, then 0.5 mg 1h later). Never exceed this. Old 'dose to diarrhea' regimens are lethal.

Clinical Focus

Extremely narrow therapeutic index. Fatal in overdose. Severe GI symptoms indicate toxicity.

Bottom Line

Colchicine is a first-line treatment for acute gout flares and pericarditis, but has an extremely narrow therapeutic index with severe GI toxicity and fatal overdose potential.

Formulation & Access

Brand Names

Lengout, Colgout

Oral Routes

Tablets (500 mcg / 0.5 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Acute gout flares, gout prophylaxis, Familial Mediterranean Fever.

Off-Label

OFF

Acute pericarditis (reduces inflammation and recurrence).

Clinical Place

First-line for acute gout if NSAIDs are contraindicated (e.g., renal failure, heart failure).

Quick reference

Class & Role

Microtubule Inhibitor — Ancient alkaloid derived from the autumn crocus.

Route / Formulation

Tablets (500 mcg / 0.5 mg). (Lengout, Colgout)

Usual Dose & Max

PO 1 mg STAT, followed by 0.5 mg one hour later (Max 1.5 mg/day). Do not repeat course for at least 3 days. Max 1.5 mg on Day 1 for acute gout (e.g., 1 mg STAT, then 0.5 mg 1h later). Never exceed this. Old 'dose to diarrhea' regimens are lethal.

Key Indication Doses

Acute Gout Flare: PO 1 mg STAT, followed by 0.5 mg one hour later (Max 1.5 mg/day). Do not repeat course for at least 3 days. Gout Prophylaxis: PO 0.5 mg OD or BD (while initiating Allopurinol). Renal Impairment: If eGFR < 30, use 0.5 mg STAT for acute flare. Do not use for daily prophylaxis.

Best Uses

Colchicine is a first-line treatment for acute gout flares and pericarditis, but has an extremely narrow therapeutic index with severe GI toxicity and fatal overdose potential.

Avoid / Cautions

Combined severe renal and hepatic impairment. Concurrent use of strong CYP3A4/P-gp inhibitors in patients with renal/hepatic impairment. Pregnancy Category D (arrests cell division).

Key Risks

Gastrointestinal: Severe, watery diarrhea, severe nausea/vomiting. (These are the first signs of cellular toxicity, not just a 'side effect'). Haematological: Bone marrow suppression (agranulocytosis, aplastic anemia) with high doses/chronic use. Neurological: Neuromyopathy (especially if combined with statins).

Key Interactions

Macrolides (Clarithromycin), Azoles, and Verapamil/Diltiazem block CYP3A4/P-gp. Colchicine levels spike exponentially, causing fatal multi-organ failure. AVOID combination. Statins (additive risk of severe myopathy/rhabdomyolysis).

Monitoring

Cease the drug IMMEDIATELY if the patient develops diarrhea or vomiting. Check U&E and eGFR before initiating. Check FBC for chronic users.

Clinical Pearl

Historically, doctors told patients to 'take a pill every hour until the pain stops or you get diarrhea'. This was poisoning the patient. The modern dose is 1.5mg TOTAL on day 1. It is equally effective and much safer.

Access

Lengout, Colgout0.5 mg tablet

Brand: Lengout, Colgout
Formulation: Tablets (500 mcg / 0

Colchicine

Microtubule Inhibitor·Musculoskeletal & Rheumatology

Acute gout flares, gout prophylaxis, Familial Mediterranean Fever

PBSANTI-INFLAMMATORYLengout, Colgout0.5 mg tabletS4+1

Max Dose

1.5 mg/day (Acute)

Half-life

27-31 h

Diarrhea

TOXICITY SIGN

Renal Adj.

MANDATORY

Rapid Summary

Overview

Ancient alkaloid derived from the autumn crocus. Highly specific anti-inflammatory for gout, acting as a direct mitotic/microtubule poison to neutrophils.

Maximum Dose

Max 1.5 mg on Day 1 for acute gout (e.g., 1 mg STAT, then 0.5 mg 1h later). Never exceed this. Old 'dose to diarrhea' regimens are lethal.

Clinical Focus

Extremely narrow therapeutic index. Fatal in overdose. Severe GI symptoms indicate toxicity.

Bottom Line

Colchicine is a first-line treatment for acute gout flares and pericarditis, but has an extremely narrow therapeutic index with severe GI toxicity and fatal overdose potential.

Formulation & Access

Brand Names

Lengout, Colgout

Oral Routes

Tablets (500 mcg / 0.5 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Acute gout flares, gout prophylaxis, Familial Mediterranean Fever.

Off-Label

OFF

Acute pericarditis (reduces inflammation and recurrence).

Clinical Place

First-line for acute gout if NSAIDs are contraindicated (e.g., renal failure, heart failure).

Quick reference

Class & Role

Microtubule Inhibitor — Ancient alkaloid derived from the autumn crocus.

Route / Formulation

Tablets (500 mcg / 0.5 mg). (Lengout, Colgout)

Usual Dose & Max

Key Indication Doses

Best Uses

Colchicine is a first-line treatment for acute gout flares and pericarditis, but has an extremely narrow therapeutic index with severe GI toxicity and fatal overdose potential.

Avoid / Cautions

Combined severe renal and hepatic impairment. Concurrent use of strong CYP3A4/P-gp inhibitors in patients with renal/hepatic impairment. Pregnancy Category D (arrests cell division).

Key Risks

Key Interactions

Monitoring

Cease the drug IMMEDIATELY if the patient develops diarrhea or vomiting. Check U&E and eGFR before initiating. Check FBC for chronic users.

Clinical Pearl

Access

Lengout, Colgout0.5 mg tablet

Brand: Lengout, Colgout
Formulation: Tablets (500 mcg / 0