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:

In studies in normal volunteers, there was no pharmacodynamic interaction between intravenous iloprost and either nifedipine, diltiazem, or captopril. However, iloprost has the potential to increase the hypotensive effect of vasodilators and antihypertensive agents. Since iloprost inhibits platelet function, there is a potential for increased risk of bleeding, particularly in patients maintained on anticoagulants. During clinical trials, iloprost was used concurrently with anticoagulants, diuretics, cardiac glycosides, calcium channel blockers, analgesics, antipyretics, nonsteroidal antiinflammatories, corticosteroids, and other medications. Intravenous infusion of iloprost had no effect on the pharmacokinetics of digoxin. Acetylsalicylic acid did not alter the clearance (pharmacokinetics) of iloprost. Although clinical studies have not been conducted, in vitro studies of iloprost indicate that no relevant inhibition of cytochrome P450 drug metabolism would be expected.
{"Brand": [], "Drug": ["diltiazem", "digoxin", "captopril", "Acetylsalicylic acid", "nifedipine", "iloprost"], "DrugGroup": ["cardiac glycosides", "corticosteroids", "diuretics", "analgesics", "nonsteroidal antiinflammatories", "anticoagulants", "vasodilators", "calcium channel blockers", "antipyretics", "antihypertensive agents"], "UnapprovedDrug": []}