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: Complete replacement of methylprednisolone by azathioprine in cyclosporine-treated primary cadaveric renal transplant recipients. In cyclosporine (CsA)-treated renal transplant recipients complete corticosteroid withdrawal followed by CsA monotherapy has been associated with severe rejection episodes in a significant proportion of patients. We report the results of replacement of steroids by azathioprine ( AZA ) in 25 primary cadaveric renal transplant recipients initially treated with CsA and methylprednisolone ( MP ) . MP taper was started 8.8 +/- 5.6 months posttransplant when the MP dose was either 10 mg/day or 20 mg every other day. MP was tapered off over a 5-month period. At the initiation of MP taper, AZA was added at 1 mg/kg/day and increased to 1.5 mg/kg/day after two months. The CsA dose was adjusted to maintain trough serum levels as measured by radioimmunoassay (RIA) of 50-75 ng/ml, during and after MP withdrawal. Seventeen patients have remained continuously off MP for 14.6 +/- 5.0 months with stable renal function. Reinstitution of MP at 10 mg/day was required in 8 patients, 6 for rejection (1.8 +/- 0.7 months after MP withdrawal), 1 for AZA-induced leukopenia, and 1 for de novo glomerulopathy. Renal function returned to baseline in all 6 patients with rejection after reinstitution of MP. Two of these patients have again been successfully retapered off MP. In the patients withdrawn from MP, body weight and mean arterial blood pressure had decreased by 2.1 +/- 1.3 kg (P less than .05) and 11 +/- 7 mmHg (P less than .05), respectively, at the time of the most recent follow-up compared with values at the initiation of steroid withdrawal. The number of blood pressure medications per patient decreased by 38% (P less than .05) and 6 patients were able to discontinue all antihypertensive drugs after cessation of steroids. Discontinuation of MP also resulted in a decrease in serum cholesterol concentration from 248 +/- 50 to 217 +/- 55 mg/dl (P less than .05). We conclude that steroids can be replaced by AZA in the majority of CsA-treated primary cadaveric renal transplant recipients by the end of the first posttransplant year without an adverse effect on graft survival. This protocol resulted in significant reductions in serum cholesterol, mean arterial blood pressure, and body weight, and may avoid the long-term side effects of steroid therapy.

sentence: We report the results of replacement of steroids by azathioprine ( AZA ) in 25 primary cadaveric renal transplant recipients initially treated with CsA and methylprednisolone ( MP ) .
[["azathioprine", "CsA", "POS"]]