Dose and Dosage:
- The usual starting dose of colchicine for acute gout flare is 1.2 mg (2 tablets) followed by 0.6 mg (1 tablet) one hour later.
- Maximum dose for acute gout flare: 1.8 mg in 1 hour.
- For prophylaxis of gout flares, the typical dose is 0.6 mg once or twice daily.
Frequency:
- For acute gout flare: Repeat the dosing as needed, but no more than every 3 days.
- For prophylaxis: Daily dosing may be recommended.
Route of Administration (ROA):
- Colchicine is usually taken orally as tablets.
- It can also be administered intravenously in certain situations, such as during acute gout flares in hospitalized patients.
Mechanism of Action (MOA):
- Colchicine inhibits microtubule polymerization, disrupting various cellular processes such as cell division, motility, and secretion.
- In gout, it inhibits leukocyte migration, phagocytosis, and the release of inflammatory mediators.
Pharmacokinetics (PK):
- Colchicine is well-absorbed after oral administration, with peak plasma concentrations reached within 2-4 hours.
- It undergoes extensive hepatic metabolism and is excreted mainly in the feces.
- Its elimination half-life is approximately 9-10 hours.
Pharmacodynamics (PD):
- Colchicine binds to tubulin, leading to microtubule depolymerization and inhibition of neutrophil chemotaxis and activity.
Pathophysiology:
- Colchicine works by interrupting the process of inflammation and cellular proliferation involved in conditions such as gout and familial Mediterranean fever (FMF).
- It inhibits the deposition of urate crystals in the joints and tissues, reducing the inflammatory response.
Indications:
- Acute gout flares
- Prophylaxis of gout flares
- Familial Mediterranean fever (FMF)
- Pericarditis and other inflammatory conditions
Contraindications:
- Hypersensitivity to colchicine
- Severe renal or hepatic impairment
- Concurrent use of potent CYP3A4 inhibitors or P-glycoprotein inhibitors
- Use in patients with gastrointestinal disorders such as inflammatory bowel disease
Drug Interactions:
- Potent inhibitors of CYP3A4 and P-glycoprotein, such as clarithromycin, ketoconazole, and cyclosporine, can increase colchicine levels and toxicity.
- Concurrent use with statins may increase the risk of myopathy and rhabdomyolysis.
- Careful monitoring and dose adjustments may be necessary when colchicine is used with other medications.
Monitoring and Laboratory Tests:
- Monitoring for adverse effects such as gastrointestinal symptoms, myopathy, and leukopenia is essential during colchicine therapy.
- Laboratory tests may include complete blood count (CBC), liver function tests, and renal function tests as clinically indicated.
Why is this medication prescribed?
- Colchicine is prescribed for the treatment and prevention of acute gouty attacks and familial Mediterranean fever (FMF). It works by reducing inflammation and pain caused by crystal deposits in the joints.
How should this medicine be used?
- The medication is usually taken orally with or without food.
- Follow the dosage instructions provided by your healthcare provider.
- Do not exceed the recommended dose or take it more frequently than prescribed.
Other uses for this medicine
- Colchicine may also be used off-label for other conditions such as pericarditis and other inflammatory disorders.
What special precautions should I follow?
- Inform your doctor about any allergies or medical conditions you have before taking colchicine.
- Tell your doctor about all the medications you are currently taking, including over-the-counter and herbal supplements.
- Avoid drinking alcohol while taking colchicine as it may increase the risk of side effects.
What special dietary instructions should I follow?
- There are no specific dietary restrictions associated with colchicine use.
- However, maintaining a healthy diet and staying hydrated may help manage symptoms of gout.
What should I do if I forget a dose?
- If you miss a dose of colchicine, take it as soon as you remember.
- However, if it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule.
- Do not double the dose to make up for a missed one.
What side effects can this medication cause?
- Common side effects of colchicine include nausea, vomiting, diarrhea, and abdominal pain.
- Serious side effects may include muscle weakness, numbness or tingling in the fingers or toes, and unusual bruising or bleeding.
- Contact your doctor immediately if you experience any severe or persistent side effects.
What should I know about storage and disposal of this medication?
- Store colchicine at room temperature away from moisture and heat.
- Keep it out of reach of children and pets.
- Do not use colchicine after the expiration date printed on the label.
In case of emergency/overdose
- If you suspect an overdose of colchicine, seek medical attention immediately.
- Symptoms of overdose may include severe vomiting, diarrhea, muscle weakness, and difficulty breathing.
- Do not attempt to induce vomiting unless instructed by a healthcare professional.