Glucosamine
Glucosamine
Generic Name
Glucosamine
Mechanism
- Glucosamine is a naturally occurring amino‑sugar and a key building block of glycosaminoglycans, the core components of cartilage matrix.
- In cartilage, it acts as a substrate for glucuronic acid and N‑acetylglucosamine, which are polymerized into hyaluronan and chondroitin sulfate.
- By replenishing these precursors, glucosamine is believed to:
- Stimulate chondrocyte synthesis of extracellular matrix.
- Inhibit collagenase and aggrecanase activity, reducing cartilage breakdown.
- Modulate inflammatory cytokines (IL‑1β, TNF‑α) in vitro, though clinical relevance remains uncertain.
- Net effect: slowing of cartilage erosion and modest symptom relief in osteoarthritis (OA) patients, with the strongest evidence in knee OA.
Pharmacokinetics
| Parameter | Data (oral) | Notes |
| Absorption | ~10–20 % of a dose reaches systemic circulation. | Absorbed mainly in the small intestine; pre‑absorptive colonic metabolism reduces bioavailability. |
| Onset | Peak plasma concentration 1–4 h post‑dose. | Delayed onset may account for slower symptomatic improvement. |
| Distribution | Widely distributed; low plasma protein binding (~10 %). | Concentrates in highly vascular tissues, including synovial fluid. |
| Metabolism | Hepatic glucuronidation via UGT enzymes. | No major drug interactions reported. |
| Elimination | Renal excretion of metabolites; t½ ≈ 1–3 h. | Caution in severe renal impairment; dose adjustments not routinely required. |
| Food Effect | Slight delay with high‑fat meals; no clinically significant change. | Can be taken with or without food. |
Indications
- Primary: Management of mild to moderate osteoarthritis of the knee, hip, and hand.