You will be shown a paragraph from a biomedical research article. Your task is to extract all drug combinations appearing in a specific sentence within in the paragraph. Each drug combination should be assigned to one of the following three categories:

- POS: Indicates a positive interaction between the drugs in the combination; for instance, drugs that have an additive or synergistic effect.
- NEG: Indicates a negative interaction between the drugs in the combination; for instance, combining these drugs might result in adverse side effects, or might reduce their efficacy.
- COMB: Indicates that the drugs are given in combination, but the type of interaction between the drugs cannot be determined based on the provided context.

Please format your answer as a json array. Each entry in the array should itself be an array formatted as [<drug_1>, <drug_2>, ..., <drug_n>, <category>] where <category> is one of the three categories listed above and <drug_1>, ..., <drug_n> are drug names copied verbatim from the input sentence. Different combinations may involve different numbers of drugs; in other words, the `n` in <drug_n> may vary.

As an example, the following output describes two extracted drug combinations; one between two drugs, and one between three drugs:

[["artesunate", "artemether", "COMB"], ["Nifedipine", "Labetalol", "Prazosin", "POS"]]

The paragraph and specific sentence are below. You should only extract relationships expressed in the specific sentence; the paragraph is provided for context.

In your output, return only the json array and no other text. If no drug combinations appear, return an empty array `[]`.

paragraph: In vitro activity of fosfomycin in combination with vancomycin or teicoplanin against Staphylococcus aureus isolated from device-associated infections unresponsive to glycopeptide therapy. fosfomycin is a molecule that inhibits the early stage of peptidoglycan synthesis and shows a broad-spectrum bactericidal activity against Gram-positive and Gram-negative bacteria. Using the Killing-curve method , we tested the in vitro bactericidal activity of fosfomycin alone or in combination with vancomycin or teicoplanin at a concentration of 8 microg/mL , that is easily achievable in serum at standard dosing regimens , against seven methicillin-resistant Staphylococcus aureus strains , isolated from patients with well documented device-associated infections unresponsive to or relapsing after glycopeptide therapy . MICs of vancomycin ranged from 1 to 4 microg/mL, MICs of teicoplanin from 2 to 8 microg/mL; MICs of fosfomycin were 8 microg/mL for two strains and >128 microg/mL for the remaining strains. The seven strains proved tolerant when tested for vancomycin and teicoplanin used alone at 2x MIC concentration. fosfomycin was bactericidal (reduction of 2 log of the inoculum) only against the two susceptible strains. In all cases both vancomycin and teicoplanin in combination with fosfomycin developed bactericidal synergism already at a concentration of 1x MIC. If these results are confirmed by in vivo experiments, the combination of fosfomycin with glycopeptides might be useful for treating device-associated infections, and in preventing the phenomenon of increasing MICs for glycopeptides.

sentence: Using the Killing-curve method , we tested the in vitro bactericidal activity of fosfomycin alone or in combination with vancomycin or teicoplanin at a concentration of 8 microg/mL , that is easily achievable in serum at standard dosing regimens , against seven methicillin-resistant Staphylococcus aureus strains , isolated from patients with well documented device-associated infections unresponsive to or relapsing after glycopeptide therapy .
[["fosfomycin", "vancomycin", "COMB"], ["fosfomycin", "teicoplanin", "COMB"]]