Colchicine: the good, the bad, the ugly and how to minimize the risks

Colchicine has an important role in managing various conditions, including gout, familial Mediterranean fever, amyloidosis, Behçet's syndrome, recurrent pericarditis and calcium pyrophosphate deposition disease. The adverse effect profile of colchicine is well understood. However, due to its narrow therapeutic index, colchicine has been associated with overdose and fatalities. When ingested in toxic amounts, the mainstay of management is supportive care. Strategies to minimize the risk of colchicine poisoning can focus on three broad causes: unauthorized access, intentional overdose and inappropriate dosing. Culturally safe and appropriate education about storage and appropriate use of colchicine is essential to minimize the risk of overdose.

Evidence of Clinically Meaningful Drug-Drug Interaction With Concomitant Use of Colchicine and Clarithromycin

INTRODUCTION

Colchicine is currently approved for the treatment of gout and familial Mediterranean fever, among other conditions. Clarithromycin, a strong inhibitor of CYP3A4 and P-glycoprotein, dramatically increases colchicine's half-life, augmenting the risk of a life-threatening adverse reaction when used inadvertently with colchicine.

OBJECTIVES

The aim of this study was to examine the evidence and clinical implications of concomitant use of colchicine and clarithromycin.

METHODS

Case reports of colchicine-clarithromycin co-administration were searched using the FDA's Adverse Event Reporting System (FAERS) database. PubMed, EMBASE, and Web of Science electronic databases were also searched from January 2005 through November 2019 for articles reporting colchicine-clarithromycin concomitant use. Individual reports were reviewed to identify consequences of coadministration, dose, days to onset of interaction, symptoms, evidence of renal disease, time to resolution of symptoms, and Drug Interaction Probability Scale (DIPS) rating.

RESULTS

The FAERS search identified 58 reported cases, nearly 53% of which were from patients aged between 65 and 85 years. Of 30 reported deaths, 11 occurred in males, and 19 in females. Other frequent complications reported in FAERS included diarrhea (31%), pancytopenia (22%), bone marrow failure (14%), and vomiting (14%). From published literature, we identified 20 case reports of concomitant exposure, 19 of which were rated 'probable' and one 'possible' according to DIPS rating. Of these cases, four 'probable' patients expired. The documented onset of colchicine toxicity occurred within 5 days of starting clarithromycin, and death within 2 weeks of concomitant exposure.

CONCLUSION

Clinical manifestations of colchicine-clarithromycin interaction may resemble other systemic diseases and may be life threatening. Understanding this clinically meaningful interaction can help clinicians avoid unsafe medication combinations.

Old Drugs for New Indications in Cardiovascular Medicine

Inflammation participates in the initiation and progression of atherosclerotic cardiovascular disease, and it is a critical inciting factor leading to acute ischemic events. Evidence has shown that certain anti-inflammatory medications used to treat non-atherosclerotic inflammatory diseases reduce cardiovascular events. This article reviews evidence that commonly used anti-inflammatory therapies (colchicine, allopurinol, methotrexate), reduce cardiovascular events. We discuss potential mechanisms of action, efficacy, and safety of these therapies and propose a clinical trials design to investigate their efficacy.