Products
Diacerein is not approved in many countries. In Austria, it is commercially available in capsule form (Verboril, Artrolyt).
Structure and properties
Diacerein (C19H12O8, Mr = 368.3 g/mol) is a diacetylated rhein and is therefore also known as diacetylrhein. It is a prodrug and is rapidly metabolized in the body to its active metabolite rhein. Rhein is an anthranoid and an ingredient of rhubarb root (Rhei radix).
Effects
Diacerein (ATC M01AX21) and its metabolite rhein are anti-inflammatory, analgesic, antiarthrotic, antioedematous, and laxative. Effects include inhibition of cytokines (e.g., interleukins), proteolytic enzymes, and oxygen radicals. Furthermore, rhein seems to favor the synthesis of cartilage components. We cannot comment on the actual clinical efficacy. A 2006 Cochrane review evaluated the drug positively (Fidelix et al., 2006).
Indications
For the treatment of degenerative joint disease (osteoarthritis).
Dosage
According to the SmPC. Capsules are taken twice daily after meals with liquid. During the first 2-4 weeks, only one capsule should be taken per day.
Contraindications
Diacerein is contraindicated in hypersensitivity, severe hepatic insufficiency, inflammatory bowel disease, intestinal obstruction, painful lower abdominal pain of unknown cause, in children and adolescents under 18 years of age, and during pregnancy and lactation. For complete precautions, see the drug label.
Interactions
Antacids may reduce absorption of diacerein to a significant extent and should be taken 1-2 hours apart. Diacerein may cause hypokalemia, which increases the risk for cardiac arrhythmias with cardiac glycosides such as digoxin.
Adverse effects
Rhine and rhubarb root are known laxatives. Digestive symptoms such as diarrhea, abdominal pain, soft and frequent stools, and flatulence are therefore among the most common potential adverse effects. Rarely, pigmentation of the mucous membrane of the colon and very rarely liver disease have been reported. Rhine can discolor urine to a brownish to reddish color, which is harmless but can be disconcerting to patients.
