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 rofecoxib on antihypertensive effects of candesartan in experimental models of hypertension. Given the high prevalence of hypertension, concomitant use of nonsteroidal anti-inflammatory drugs and antihypertensive medications is commonly encountered in clinical practice. The present study was designed to study the effect of indomethacin, nimesulide, and rofecoxib on blood pressure (BP) in normotensive and hypertensive rats and also to investigate the effect of rofecoxib on BP control in candesartan-treated hypertensive rats. Male Wistar rats weighing 150-200 g were divided into three groups: control, DOCA-hypertensive, and L-NAME-hypertensive rats. All the rats were given indomethacin (15 mg/kg body weight), nimesulide (20 mg/kg body weight), rofecoxib (10 mg/kg body weight), or vehicle orally and daily for 6 weeks. Hypertensive rats in separate groups were treated with either candesartan ( 1 mg/kg body weight ) alone or a combination of candesartan ( 1 mg/kg body weight ) and rofecoxib ( 10 mg/kg body weight ) orally and daily for 6 weeks . BP measurements were performed using tail cuff method at baseline and 1-week intervals throughout the treatment period. All the three COX inhibitors resulted in increase in BP, but mean change in BP was the highest with rofecoxib. rofecoxib-treated L-NAME-hypertensive rats exhibited a significant increase in mean arterial pressure at 6 weeks (168.3+/-5.7 mmHg) as compared with DOCA-hypertensive rats (128.818+/-7.2 mmHg). Administration of rofecoxib L-NAME-hypertensive rats treated with candesartan resulted in a significant increase in BP. Systolic BP at 0 week (107.0+/-4.2 mmHg) rose to 141.6+/-2.0 mmHg at 6 weeks. Systolic BP at 2, 4, and 6 weeks was significantly higher as compared with (L-NAME+candesartan)- and (rofecoxib+candesartan)-treated group. In conclusion, concomitant use of rofecoxib resulted in poor BP control by candesartan in L-NAME-hypertensive rats.

sentence: Hypertensive rats in separate groups were treated with either candesartan ( 1 mg/kg body weight ) alone or a combination of candesartan ( 1 mg/kg body weight ) and rofecoxib ( 10 mg/kg body weight ) orally and daily for 6 weeks .
[["candesartan", "rofecoxib", "NEG"]]