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: Effect of amlodipine, lisinopril and allopurinol on acetaminophen-induced hepatotoxicity in rats. Exposure to chemotherapeutic agents such as acetaminophen may lead to serious liver injury. Calcium deregulation, angiotensin II production and xanthine oxidase activity are suggested to play mechanistic roles in such injury. ### objective This study evaluates the possible protective effects of the calcium channel blocker amlodipine , the angiotensin converting enzyme inhibitor lisinopril , and the xanthine oxidase inhibitor allopurinol against experimental acetaminophen-induced hepatotoxicity , aiming to understand its underlying hepatotoxic mechanisms . ### Material And Methods Animals were allocated into a normal control group, a acetaminophen hepatotoxicity control group (receiving a single oral dose of acetaminophen; 750 mg/kg/day), and four treatment groups receive N-acetylcysteine (300 mg/kg/day; a reference standard), amlodipine (10 mg/kg/day), lisinopril (20 mg/kg/day) and allopurinol (50 mg/kg/day) orally for 14 consecutive days prior to acetaminophen administration. Evaluation of hepatotoxicity was performed by the assessment of hepatocyte integrity markers (serum transaminases), oxidative stress markers (hepatic malondialdehyde, glutathione and catalase), and inflammatory markers (hepatic myeloperoxidase and nitrate/nitrite), in addition to a histopathological study. ### results Rats pre-treated with amlodipine, lisinopril or allopurinol showed significantly lower serum transaminases, significantly lower hepatic malondialdehyde, myeloperoxidase and nitrate/nitrite, as well as significantly higher hepatic glutathione and catalase levels, compared with acetaminophen control rats. Serum transaminases were normalized in the lisinopril treatment group, while hepatic myeloperoxidase was normalized in the all treatment groups. Histopathological evaluation strongly supported the results of biochemical estimations. ### conclusion amlodipine, lisinopril or allopurinol can protect against acetaminophen-induced hepatotoxicity, showing mechanistic roles of calcium channels, angiotensin converting enzyme and xanthine oxidase enzyme in the pathogenesis of hepatotoxicity induced by acetaminophen.

sentence: This study evaluates the possible protective effects of the calcium channel blocker amlodipine , the angiotensin converting enzyme inhibitor lisinopril , and the xanthine oxidase inhibitor allopurinol against experimental acetaminophen-induced hepatotoxicity , aiming to understand its underlying hepatotoxic mechanisms .
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