Table 2. Overview of currently used substances for the treatment of osteoarthritis, and the evidence base.

Substance	Application	Evidence base
Glucosamine*	p. o.	Contradictory; the GAIT-Studie did not show any symptomatic or structure-preserving effects (evidence level I) (4, 5). Structure-preserving effect reported in other studies (evidence level I) (e59, e62).
Chondroitin*	p. o.	Contradictory; the GAIT-Studie did not show any symptomatic or structure-preserving effects (evidence level I) (4, 5). Symptomatic and structure-preserving effects reported in another study (evidence level I) (6)
Diacerein*	p. o.	Mild symptomatic effect (evidence level I) (2, 7)
Doxycycline	p. o.	Indications of structure-preserving effects (evidence level I) (2)
IL-1 receptor antagonist	s. c., i. a	Primarily established for oral therapy of rheumatoid arthritis. Suitability for treatment of osteoarthritis is currently under investigation (2).
Fibroblast growth factor-18	i. a.	In an osteoarthritis animal model, improved cartilage repair (e69); currently phase I and phase II studies of intra-articular injection for the treatment of osteoarthritis and traumatic cartilage defects (e70, e71)
Hyaluronic acid*	i. a.	Temporary symptomatic effect (8, e65– e67); no evidence of structure-preserving attributes
ICE inhibitors bisphosphonates calcitonin MMP inhibitors estrogen	p. o. p. o., i. v. i. v., i.m., s.c. p. o. p. o., TTS	Symptomatic structure-preserving effects have been described in individual studies. The data situation remains unclear, however, as controlled studies with large numbers of cases are lacking.

Application methods: TTS, transcutaneous therapeutic system; p. o., per orem; i. a., intra-articular; i. v., intravenous; i. m., intramuscular; s. c., subcutaneous ^*SYSADOA (symptomatic slow acting drugs in osteoarthritis). ICE, Interleukin-1ß-converting-enzyme; MMP, matrix metalloproteinase; Confirmed clinical proof is so far lacking for the the classification of DMOADs (disease modifying osteoarthritis drugs), which we included in our article, which stop cartilage degeneration or even reverse it.