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: Comparative study of ceftriaxone monotherapy versus a combination regimen of cefuroxime plus gentamicin for treatment of serious bacterial infections : the efficacy , safety and effect on fecal flora . To assess the efficacy of once daily monotherapy relative to standard combination antibiotic therapy for the initial management of patients suspected of serious bacterial infections, we conducted a randomized trial comparing ceftriaxone (Rocephin) with a combination of cefuroxime plus gentamicin. Of 105 patients, 53 were treated with ceftriaxone alone and 52 with the combination; 13 patients were considered not evaluable. 42 of 53 patients given ceftriaxone and 33 of 52 given cefuroxime plus gentamicin responded to treatment (p = 0.07). Three patients given ceftriaxone and 6 who received gentamicin plus cefuroxime died (p = 0.28). Definite bacterial infections were identified in 67 patients; of the evaluable patients with a definite infection 27 of 29 who received ceftriaxone and 21 of 31 who were treated with the combination were cured (p = 0.01). No difference was found in the number of side effects. However, therapy had to be discontinued due to treatment failure, an adverse effect or death in 1 of 33 patients given ceftriaxone and in 11 of 34 given the combination (p = 0.002). ceftriaxone was found to have an impact on the count of E. coli in intestinal microflora. Changes in normal bacterial composition did not lead to the overgrowth with resistant Enterobacteriaceae or Pseudomonas, however, colonization by yeast was observed. Using ceftriaxone reduced the cost of antimicrobial therapy per patient by 107 pounds (US$ 183). Moreover, the total time save per patient due to decreased nursing and drug administration time per day was 40 min.(ABSTRACT TRUNCATED AT 250 WORDS)

sentence: Comparative study of ceftriaxone monotherapy versus a combination regimen of cefuroxime plus gentamicin for treatment of serious bacterial infections : the efficacy , safety and effect on fecal flora .
[["cefuroxime", "gentamicin", "NEG"]]