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: Evaluation of irinotecan in combination with 5-fluorouracil or etoposide in xenograft models of colon adenocarcinoma and rhabdomyosarcoma. irinotecan [7-ethyl-10-(4-[1-piperidino]-1-piperidino)-carbonyloxy-camptothec in] administered i.v. in two courses, each course consisting of administration every day for 5 days [(dx5)2] on days 1-5 and 8-12, has demonstrated significant activity against advanced human tumor xenografts derived from colon adenocarcinomas and several childhood cancers. To build on this therapy, we have evaluated the combination of irinotecan given on this schedule with 5-fluorouracil given on days 1, 7, and 14 with or without leucovorin [(dx5)3 i.v.] against colon tumors, or combined with etoposide administered (dx5)2 i.v. either 2 h before or 2 h after irinotecan for treatment of colon tumors and rhabdomyosarcomas. A combination of 5-fluorouracil at 75% and irinotecan at 50% of their respective maximum tolerated doses when administered as single agents on this schedule gave acceptable toxicity. Against colon adenocarcinoma xenografts, 5-fluorouracil did not enhance the response rate compared with that obtained with the optimum dose of irinotecan given as a single agent. Against GC3/TK- xenografts, which lack thymidine kinase and cannot salvage thymidine to circumvent the inhibition of thymidylate synthase, the addition of leucovorin to the combination increased the complete response rate from 10 to >90%, whereas the response rates for the optimal doses of irinotecan or 5-fluorouracil, as single agents, were 30 and <10%, respectively. etoposide d x 5 i.v. for two or three courses or (d x 5)3 p.o. did not cause objective regression of any colon tumors. In contrast, three of five rhabdomyosarcoma lines demonstrated a high frequency of partial regressions or complete regressions when treated (d x 5)1 i.v. Repetitive courses [e.g., (d x 5)2 or (d x 5)3] i.v. or p.o. or by 4-h infusion d x3 i.v. were either equally effective or less effective. Irinotecan and etoposide were combined using the ( d x 5)2 i.v . schedule for both drugs , in which irinotecan was given 2 h before or 2 h after the administration of etoposide . Each drug could be combined at only 38% of its respective maximum tolerated dose when administered as a single agent, indicating greater than additive toxicity. Toxicity was similar irrespective of the sequence of administration and was manifested by loss of weight (73% of the initial weight, nadir day 7), myelosuppression, and prolonged thrombocytopenia. The responses of colon carcinomas to the combination given in either sequence were similar to that achieved with irinotecan given alone at the same dose as used in the combination. Similarly, when etoposide was given before irinotecan, the responses of rhabdomyosarcomas were similar to those for irinotecan. However, in experiments in which etoposide was administered 2 h after each dose of irinotecan, there was significant antagonism of the antitumor activity of irinotecan.

sentence: Irinotecan and etoposide were combined using the ( d x 5)2 i.v . schedule for both drugs , in which irinotecan was given 2 h before or 2 h after the administration of etoposide .
[["Irinotecan", "etoposide", "NEG"], ["irinotecan", "etoposide", "NEG"]]