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 rational use of qinghaosu and its derivatives: what is the future of new compounds?  In Thailand , artesunate and artemether are the mainly used antimalarials for treatment of severe or multidrug resistant falciparum malaria . However, their availability (supply) and the registration requirements are the major limitations for their large-scale use. At Bangkok Hospital for Tropical Diseases, Thailand, we have studied the new artemisinin derivatives, dihydroartemisinin and arteether, and artesunate suppositories. We found that the three preparations are well tolerated, safe, and efficacious.

sentence: In Thailand , artesunate and artemether are the mainly used antimalarials for treatment of severe or multidrug resistant falciparum malaria .
[]