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: Safety and efficacy of lamivudine-zidovudine combination therapy in zidovudine-experienced patients. A randomized controlled comparison with zidovudine monotherapy. Lamivudine European HIV Working Group.  To compare the safety and efficacy of 2 doses of lamivudine given in combination with zidovudine with continued zidovudine monotherapy . ### design Double-blind, randomized, multicenter, comparative trial of 223 patients treated for 24 weeks. ### setting Patients from 32 hospitals in Europe were enrolled throughout a 1-year period. ### patients Adult human immunodeficiency virus type 1 (HIV-1)-positive, zidovudine-experienced ( > or = 24 weeks prior zidovudine) patients with CD4+ cell counts between 0.10 and 0.40 x 10(9)/L (100-400 cells/microL). ### intervention Patients received either 200 mg of zidovudine every 8 hours, 150 mg of lamivudine every 12 hours plus zidovudine, or 300 mg of lamivudine every 12 hours plus zidovudine for 24 weeks. All patients were then allowed to receive zidovudine and open-label lamivudine combination therapy. Twelve patients withdrew because of adverse events during the 24-week treatment period. ### Main Outcome Measures Efficacy was measured by evaluating immunological and viral load changes, and safety was assessed by evaluating clinical manifestations and laboratory indexes of toxic effects. ### results Patients receiving low- or high-dose combination therapy had greater treatment effects compared with patients receiving continued zidovudine monotherapy during the first 24 weeks as documented by changes in CD4+ cell counts (+0.04 vs +0.03 vs -0.02 x 10(9)/L, respectively; P < .001); log10 HIV-1 RNA as measured by the Roche assay (-0.96 vs -0.77 vs +0.07 copies/mL, respectively; P < .001) or log10 HIV-1 RNA measured by the quantitative nucleic acid sequence-based amplification assay (-0.59 vs -1.06 vs -0.02 copies/mL, respectively; P < .011); and immune-complex dissociated (ICD) p24 antigen (-74% vs -68% vs +27%, respectively; P < .001). There were no statistically significant differences in viral measurements, in CD4+ cell counts, or in safety profile between the groups receiving 2 doses of lamivudine in combination with zidovudine. The effects on CD4+ cell counts and ICD p24 antigen were sustained throughout 48 weeks for patients continuing combination therapy. Patients switching to combination therapy at week 24 showed improvement. ### conclusion In zidovudine-experienced HIV-1-infected patients, combination treatment with lamivudine and zidovudine is well tolerated and provides greater and more sustained increases in CD4+ cell counts and decreases in viral load than continued zidovudine monotherapy.

sentence: To compare the safety and efficacy of 2 doses of lamivudine given in combination with zidovudine with continued zidovudine monotherapy .
[["lamivudine", "zidovudine", "POS"]]