Methimazole-Induced Insulin Autoimmune Syndrome in a Korean Patient with Graves’ Disease Treated with Propylthiouracil: a Case Report and Literature Review
	    		
		   		
		   			
		   		
	    	
    	 
    	10.11106/ijt.2024.17.2.295
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Sun Hee KIM
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Cho-ok BAEK
			        		
			        		;
		        		
		        		
		        		
			        		Sun Kyung SONG
			        		
			        		;
		        		
		        		
		        		
			        		Ji Hye KIM
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Division of Endocrinology, Department of Internal Medicine, Presbyterian Medical Center, Jeonju, Korea
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:CASE REPORTS
 
        	
        	
            
            
            	- From:International Journal of Thyroidology
	            		
	            		 2024;17(2):295-298
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:English
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	 Insulin autoimmune syndrome (IAS) is rare. Herein, we report a case of methimazole-induced IAS successfully treated with propylthiouracil (PTU) and review related literature on Korean cases. A 48-year-old woman visited our hospital due to a hypoglycemic mental alteration. She had been taking medications for Graves’ disease including methimazole. Laboratory tests revealed a low serum glucose, high insulin, C-peptide, and anti-insulin antibody titer level. Abdominal computed tomography was negative for pancreatic tumors. Therefore, the patient was diagnosed with methimazole-induced IAS. After methimazole discontinuation and frequent diet, her hypoglycemic symptoms improved. She was treated with PTU for Graves’ disease. Previously, six cases of methimazole-induced IAS have been reported in Korea. Our case was the first in Korea to respond well to medical therapy (PTU) without other hypoglycemic treatments, such as steroids. PTU, which does not contain a sulfhydryl group, can be an option for the treatment of Graves’ disease and methimazole-induced IAS.