What is Arthrosamid?
Arthrosamid is an injectable 2.5% cross-linked polyacrylamide hydrogel (2.5 iPAAG) used for intra-articular treatment of osteoarthritis pain, particularly in the knee joint. 1
Mechanism and Composition
- Arthrosamid consists of 2.5% cross-linked polyacrylamide hydrogel that is polymerized from acrylamide monomers 1
- The product has demonstrated no neurotoxic or cytotoxic effects in human neuronal cell cultures at concentrations up to 20% for 96 hours, despite being derived from the neurotoxic compound acrylamide 1
- It functions as an intra-articular injection therapy, similar to other injectable treatments like hyaluronic acid and corticosteroids that are established options for osteoarthritis management 2
Clinical Context and Treatment Positioning
Arthrosamid fits within the established treatment algorithm for osteoarthritis as an intra-articular therapy option:
First-line treatments should be exhausted before considering intra-articular injections:
- Paracetamol (acetaminophen) up to 4000 mg daily remains the preferred initial pharmacologic treatment 2, 3
- Topical NSAIDs (such as diclofenac 1-1.5% gel) for localized joint pain 3
- Non-pharmacologic interventions including structured exercise programs with quadriceps strengthening, weight reduction if overweight, and patient education 3
Intra-articular therapy is indicated when:
- Patients have not obtained adequate relief through systemic medications 2
- Oral NSAIDs are contraindicated due to gastrointestinal, cardiovascular, or renal risk factors 2, 3
- There is acute exacerbation of knee pain, especially with joint effusion 2
Comparison to Other Intra-Articular Options
Established intra-articular treatments include:
- Corticosteroid injections (e.g., triamcinolone hexacetonide) for acute pain episodes with inflammation and effusion 2
- Hyaluronic acid preparations, which have demonstrated efficacy in relieving pain not adequately controlled with non-invasive therapies, though effect sizes are relatively small and suitable patients are not well-defined 2
Safety Profile
- The 2.5% cross-linked polyacrylamide formulation showed no statistically significant effects on cell survival, cell death, apoptosis, or neurite network integrity in human neuronal cell testing 1
- This distinguishes the cross-linked hydrogel from its acrylamide precursor, which is known to be neurotoxic 1
Clinical Considerations
Common pitfalls to avoid:
- Do not use intra-articular therapies as first-line treatment; they are reserved for patients who fail conservative management 2
- Ensure patients have tried adequate therapeutic trials of at least two NSAIDs (3 months at maximal recommended dose unless contraindicated) before advancing to injectable therapies 2
- Consider cardiovascular and gastrointestinal risk profiles when oral NSAIDs are being considered as alternatives 2, 3
When oral medications remain necessary:
- Exercise therapy demonstrates equivalent pain relief and functional improvement compared to oral NSAIDs and paracetamol at 4,8, and 24 weeks, with superior safety profiles 2
- Opioid analgesics with or without paracetamol serve as alternatives when NSAIDs are contraindicated, though counsel patients on increased adverse effects and dependence risk, particularly in elderly populations 2