22 Apr 2010
The Department of Health (DH) today (April 22) drew public's attention to the risk of severe or even fatal liver damage with the use of drugs containing PTU, a pharmaceutical agent which has been used for long for the treatment of hyperthyroidism (overactive thyroid).
Through the Department's drug surveillance scheme, DH noted that the United States Food and Drug Administration (USFDA) announced on Apr 21 (US time) that with the findings of severe, sometimes fatal, liver injury reports in both adult and paediatric patients using PTU, the addition of a boxed warning to the label for PTU is required. The aim is to help patients understand this very serious potential risk.
The USFDA discovered the findings after a search of postmarketing adverse event reports for PTU was conducted in order to better understand the potential for liver injury with PTU.
Known side effects of PTU include encephalopathy besides liver damages, ranging from asymptomatic to hepatitis to necrosis.
As a result, 34 severe liver injury cases were identified, comprising 23 adults and 11 paediatric patients. Among the former, 13 died and five had liver transplants. Two fatalities and seven transplants were noted in the children group; one died while on the transplant list.
In Hong Kong, five drugs, namely CP-PTU 50mg Tablet (HK-47993), Pyroid 50mg Tablet (HK-59451), Propylthiouracil 200mg Tablet (HK-04961), Propylthiouracil 50mg Tablet (HK-04990) and Propylthiouracil 50mg Tablet (HK-07500), containing PTU are registered with the Pharmacy and Poisons Board (PPB). They can only be sold in dispensaries on a doctor's prescription and under the supervision of a pharmacist.
The surveillance finding has already been referred to the Registration Committee of the PPB which will review the registration requirements for PTU in its next meeting.
A DH spokesman advised members of the public using drugs containing PTU to consult their healthcare professionals should they encounter problems. However, they must not stop taking PTU unless being told to do so by the professionals.