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: Inhibition by metyrapone of the accumulation of nicotine-14C in bronchial epithelium of mice. Further studies have been conducted in an attempt to define the mechanism of the intense accumulation of radioactivity in bronchial epithelium following the administration of nicotine-14C to mice. Male and female pigmented (C57B1/6J) and nonpigmented (A/HeJ) mice were studied by whole-body autoradiography following administration of either nicotine-14C (methyl- or 2'-labeled) or nicotine-1'-N-oxide-14C. When each of these compounds was administered at the same specific activity the radioactivity retained in the bronchial epithelium was much greater for the methyl-labeled nicotine-14C than for the ring-labeled. Following administration of the N-oxide very little radioactivity was retained at this site and this was seen only at a few time intervals. Pretreatment with NaHCO3 , NH4Cl , SKF 525A , piperonyl butoxide , progesterone , cysteamine , phenobarbital or metyrapone prior to the administration of [methyl-14C]nicotine was studied . metyrapone totally prevented the accumulation of radioactivity in the bronchial epithelium and progesterone reduced this accumulation; the other substances used for pretreatment had no effect on the uptake of radioactivity. These results are interpreted to indicate that the accumulation of nicotine in bronchial epithelium is not accounted for by transcellular pH gradients but is due to a high affinity of nicotine for a cytochrome P-450 in this tissue which demethylates the nicotine. The relationship and significance of metabolism of nicotine in this tissue to metabolism at other sites in the body are discussed.

sentence: Pretreatment with NaHCO3 , NH4Cl , SKF 525A , piperonyl butoxide , progesterone , cysteamine , phenobarbital or metyrapone prior to the administration of [methyl-14C]nicotine was studied .
[["[methyl-14C]nicotine", "metyrapone", "POS"], ["[methyl-14C]nicotine", "progesterone", "POS"]]