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: The effect of thiabendazole on pain threshold. thiabendazole significantly increased the reaction time to thermal stimulus. However, in mice treated with morphine, the reaction time was not in any way different from those treated with combined doses of thiabendazole and morphine. thiabendazole was found to have an antinociceptive action. The protective dose for 50% of animal (ED50) against p-benzoquinone-induced writhing reflex was found to be 310 mg/kg. The ED50 for aspirin alone was 140 mg/kg. When the ED50 of aspirin was determined in combination with different dose levels of thiabendazole, it showed a marked reduction in the values reaching 50 mg/kg, when 300 mg of thiabendazole was used in combination. Toxicological studies revealed that the oral LD50 for thiabendazole in mice was 2200 mg/kg , and when combined with 140 mg/kg of aspirin , the LD50 was reduced to 900 mg/kg . These findings indicate that thiabendazole possesses an analgesic activity which is potentiated by aspirin, though aspirin was found to significantly enhance its toxicity.

sentence: Toxicological studies revealed that the oral LD50 for thiabendazole in mice was 2200 mg/kg , and when combined with 140 mg/kg of aspirin , the LD50 was reduced to 900 mg/kg .
[["thiabendazole", "aspirin", "NEG"]]