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:

Antihistamines may enhance the effects of tricyclic antidepressants, barbiturates, alcohol, and other CNS depressants. MAO inhibitors prolong and intensify the anticholinergic effects of antihistamines. Sympathomimetic amines may reduce the antihypertensive effects of reserpine, veratrum alkaloids, methyldopa and mecamylamine. Effects of sympathomimetics are increased with MAO inhibitors and beta adrenergic blockers.
{"Brand": [], "Drug": ["mecamylamine", "alcohol", "methyldopa", "reserpine"], "DrugGroup": ["CNS depressants", "Sympathomimetic amines", "Antihistamines", "tricyclic antidepressants", "barbiturates", "beta adrenergic blockers", "veratrum alkaloids", "sympathomimetics", "antihistamines", "MAO inhibitors"], "UnapprovedDrug": []}