You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Brand", "UnapprovedDrug", "Drug", "DrugGroup"].

Please return the output as a JSON object of the format: {"Brand" : ["Aspirin", ...], "DrugGroup": ["Salicyclate", ...], "Drug": ["Phenobarbital", ...], "UnapprovedDrug": ["Heroin", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Antacid: The effect of an aluminum hydroxide- and magnesium hydroxide-containing antacid (Maalox)* on the pharmacokinetics of capecitabine was investigated in 12 cancer patients. There was a small increase in plasma concentrations of capecitabine and one metabolite (5-DFCR); there was no effect on the 3 major metabolites (5-DFUR, 5-FU and FBAL). Coumarin Anticoagulants Altered coagulation parameters and/or bleeding have been reported in patients taking capecitabine concomitantly with coumarin-derivative anticoagulants such as warfarin and phenprocoumon. Patients taking coumarin-derivative anticoagulants concomitantly with capecitabine should be monitored regularly for alterations in their coagulation parameters (PT or INR). Leucovorin: The concentration of 5-fluorouracil is increased and its toxicity may be enhanced by leucovorin. Deaths from severe enterocolitis, diarrhea, and dehydration have been reported in elderly patients receiving weekly leucovorin and fluorouracil.
{"Brand": ["Maalox"], "Drug": ["aluminum hydroxide", "fluorouracil", "capecitabine", "warfarin", "5-fluorouracil", "leucovorin", "Leucovorin", "magnesium hydroxide", "phenprocoumon"], "DrugGroup": ["Coumarin Anticoagulants", "antacid", "Antacid", "coumarin-derivative anticoagulants"], "UnapprovedDrug": ["5-DFCR", "FBAL", "5-DFUR", "5-FU"]}