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: [Possibility of overcoming of ACNU resistance in an ACNU-resistant subline of C6 rat glioma].  Membrane-modifying agents such as reserpine , calcium antagonists ( nicardipine , verapamil ) and calmodulin inhibitor ( trifluoperazine ) were found to enhance the cytotoxicity of ACNU in vitro and in vivo in ACNU-resistant C 6 ( C 6/ACNU ) glioma . In in vitro experiments, uptake and retention studies with [14C] ACNU revealed that intracellular uptake and retention of ACNU in C 6 cells were larger than those in C 6/ACNU cells, and that these membrane-modifying agents increased the cellular uptake and retention of ACNU in C 6, especially in C 6/ACNU cells. The amount of ACNU in C 6/ACNU cells reached the same level as that detected in C 6/ACNU cells. When these drugs were added along with ACNU at the concentration of 10 to 20 microM to the culture in vitro, ACNU resistance was completely overcome. In in vivo experiment, reserpine, nicardipine, verapamil and trifluoperazine in doses 250 to 500 micrograms/kg intrathecally administered with 1 mg/kg ACNU 1 day after the tumor inoculation significantly enhanced the chemotherapeutic effect of ACNU in C 6/ACNU bearing (C 6/ACNU-MG) rats. It might be concluded that the mechanism of enhancement of ACNU cytotoxicity presented in in vitro and in vivo is explained by the enhanced accumulation of ACNU by these membrane-modifying agents in C 6, especially in ACNU-resistant (C 6/ACNU) cells, and, furthermore, that combination chemotherapy with ACNU and such membrane interacting drugs as reserpine, calcium antagonists (nicardipine, verapamil) and calmodulin inhibitor (trifluoperazine) could lead to the capability of overcoming resistance to ACNU in glioma.

sentence: Membrane-modifying agents such as reserpine , calcium antagonists ( nicardipine , verapamil ) and calmodulin inhibitor ( trifluoperazine ) were found to enhance the cytotoxicity of ACNU in vitro and in vivo in ACNU-resistant C 6 ( C 6/ACNU ) glioma .
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