Technologies: Pregabalin and vitamin B12 associated with uridine and cytidine (ETNA®)
Indication: Treatment of diabetic neuropathic pain
Technologies characterization: Pregabalin is an anticonvulsant indicated for the treatment of neuropathic pain in adults. Its mechanism of action is the reduction of calcium influx to regulate transmission of excitatory messages between nerve cells. ETNA ® is a combination of vitamin B12, uridine and cytidine nucleotides and it is indicated for the treatment of peripheral nerves diseases.
Question: Are ETNA ® and pregabalin safe, effective and cost-effective options in the treatment of diabetic neuropathic pain, regarding the alternatives amitriptyline and gabapentin available at SUS? Search and analysis of scientific evidence: a search for systematic reviews and economic studies was performed in the databases The Cochrane Library (via Bireme), Medline (via Pubmed), LILACS and Centre for Reviews and Dissemination (CRD). Manual search was also conducted on the internet and in the references of the studies found. Health Technology Assessments (HTA) have been selected in international agencies and in Brazilian Network for Health Technology Assessment (REBRATS). Studies published in English, Portuguese or Spanish were selected.
Summary of results of the selected studies: Nine studies were included, four systematic reviews, one clinical trial and four economic studies. Systematic reviews considering efficacy and safety of pregabalin evaluated the following outcomes: reduction in pain intensity, treatment response rate (≥50% on pain reduction), the Patient Global Impression of Change and adverse events. These reviews showed results in favor of pregabalin compared to placebo. The ETNA® Clinical trial showed results in favor of the intervention but compared to vitamin B12 alone. The results of cost-effectiveness for pregabalin considered as a measure of effectiveness the number of days with no pain or mild pain, the number of days with 30% and 50% reduction in pain and QALY gains. Only one cost-effectiveness study has not favored pregabalin.
Recommendations: The treatment for neuropathic pain is contemplated in the therapeutic guideline for chronic disease, which recommends the use of amitriptyline in monotherapy as first choice or its association with gabapentin in cases of therapeutic failure with the monotherapy. The evidences appraised here allow recommending (weakly) the use of pregabalin in replacement of gabapentin only in cases of therapeutic failure of the schemes mentioned above, since no study included direct comparisons between pregabalin and amitriptyline or gabapentin, making it impossible to support the therapeutic superiority of pregabalin compared to other drugs already used in Brazil. The recommendation is against ETNA® use due to lack of studies with sufficient evidence of quality to ensure the efficacy and safety of this intervention and justify the expense.
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