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: Suppression of plasma estrogen levels by letrozole and anastrozole is related to body mass index in patients with breast cancer. To investigate whether suppression of plasma estradiol and estrone sulfate levels by the aromatase inhibitors (AIs) anastrozole and letrozole is related to body mass index (BMI) in postmenopausal women with early estrogen receptor (ER) -positive breast cancer. Recent studies have reported that the AI anastrozole has lower effectiveness than tamoxifen in women with high BMI . This effect with high BMI might hypothetically be a result of reduced inhibition of aromatase and suppression of plasma estrogen levels and might be overcome by the use of an increased dose of anastrozole or, alternatively, the use of a more potent AI such as letrozole. ### Patients And Methods Plasma estradiol and estrone sulfate levels from a highly sensitive radioimmunoassay were available for 44 postmenopausal patients who received anastrozole (1 mg per day) for 3 months followed by letrozole (2.5 mg per day) for 3 months or the opposite sequence. Correlations between the estrogen suppression by each AI and BMI were assessed. ### results Baseline values of estradiol and estrone sulfate were significantly correlated with BMI (r = 0.57; P < .001, and r = 0.38; P = .006, respectively). Levels of estrogen in patients receiving treatment were greater at higher levels of BMI with both AIs, but although this was significant with letrozole (r = 0.35; P = .013, and r = 0.30; P = .035 for estradiol and estrone sulfate, respectively), it was not with anastrozole. Suppression of both estrogen types was greater with letrozole across the full range of BMIs in this study. ### conclusion The suppressed levels of plasma estradiol and estrone sulfate in postmenopausal women with early ER-positive breast cancer treated with the AIs anastrozole and letrozole are related to BMI.

sentence: Recent studies have reported that the AI anastrozole has lower effectiveness than tamoxifen in women with high BMI .
[]