Muscimol: GABA agonist therapy in schizophrenia

Muscimol (3-hydroxy-5-aminomethylisoxazole), originally isolated from 'Amanita muscaria', is the structural analogue of GABA. Muscimol was administered to six patients in a double-blind, placebo-controlled design. All subjects were diagnosed as having chronic schizophrenia. During high-dose muscimol treatment, all study subjects evidenced diffuse myoclonic twitching or somnolence, and many experienced vivid dreams, dizziness, and confusion. At dose levels below 5 mg, many patients experienced a tranquilizing effect from muscimol. These subjects, when receiving the active drug, reported feeling more relaxed and less anxious and claimed a positive drug experience, despite their lack of relief from psychotic thinking. No significant change in vital signs or routine laboratory studies occurred.