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: Combination treatment with aripiprazole and valproic acid for acute mania: an 8-week, single-blind, randomized controlled trial. Despite the fact that combination treatment for patients with acute bipolar is prevalent in clinical practice, the outcomes of adjunct treatment with aripiprazole and a mood stabilizer have rarely been reported. The aim of this single-blind , randomized , controlled trial was to investigate treatment efficacy and safety of aripiprazole as an adjunct to valproic acid ( Ari+Val ) , compared with haloperidol plus valproic acid ( Hal+Val ) , in acute manic patients . ### methods Treatment efficacy was prospectively assessed for 8 weeks in 42 patients with acute mania using the Young Mania Rating Scale and the Clinical Global Impression-Severity of illness scale. Emergent adverse events were assessed by the Drug-Induced Extrapyramidal Symptoms Scale and the Liverpool University Neuroleptic Side Effect Rating Scale. ### results Both Ari+Val and Hal+Val produced a high rate of response (85.7% and 92.9%, respectively) and remission (82.1% and 85.7%, respectively) after the 8-week trial. Changes in the Young Mania Rating Scale and the Clinical Global Impression-Severity of illness scale over the study period and time to remission and response were not significantly different between the 2 groups. Patients treated with Ari+Val showed significantly fewer extrapyramidal adverse events than those treated with Hal+Val (t = -2.048, F = 40, P = 0.048). However, significant weight gain was more prevalent in the Ari+Val group than the Hal+Val group (t = 2.055, F = 40, P = 0.046). ### conclusions Our findings suggest that both combination strategies with Ari+Val and Hal+Val are beneficial for acute manic episode. Although patients receiving Ari+Val showed fewer extrapyramidal symptoms than those taking Hal+Val, careful consideration of adverse events such as weight gain and sedation is warranted.

sentence: The aim of this single-blind , randomized , controlled trial was to investigate treatment efficacy and safety of aripiprazole as an adjunct to valproic acid ( Ari+Val ) , compared with haloperidol plus valproic acid ( Hal+Val ) , in acute manic patients .
[["aripiprazole", "valproic", "POS"], ["haloperidol", "valproic", "POS"]]