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: ["Disease", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Naloxone", ...], "Disease" : ["Hypotensive", ...]}. 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:

Beta-2-adrenoceptor-mediated hypokalemia and its abolishment by oxprenolol. The time course and concentration-effect relationship of terbutaline-induced hypokalemia was studied, using computer-aided pharmacokinetic-dynamic modeling. Subsequently we investigated the efficacy of oxprenolol in antagonizing such hypokalemia, together with the pharmacokinetic interaction between both drugs. Six healthy subjects were given a 0.5 mg subcutaneous dose of terbutaline on two occasions: 1 hour after oral administration of a placebo and 1 hour after 80 mg oxprenolol orally. In the 7-hour period after terbutaline administration, plasma samples were taken for determination of plasma potassium levels and drug concentrations. The sigmoid Emax model offered a good description of the relation between terbutaline concentrations and potassium effects. Oxprenolol caused decreases of 65% and 56% of terbutaline volume of distribution and clearance, respectively, and an increase of 130% of its AUC. In spite of higher terbutaline concentrations after oxprenolol pretreatment, the hypokalemia was almost completely antagonized by the beta 2-blocking action.
{"Chemical": ["potassium", "terbutaline", "Oxprenolol", "oxprenolol"], "Disease": ["hypokalemia"]}