Blistering, peeling skin: 9 develop severe reactions from taking unregistered medicines

Nine people suffered severe skin reactions and were hospitalised after consuming unregistered medicines touted to boost energy and improve alertness.

In a statement on Monday (March 10), the Health Sciences Authority (HSA) urged the public not to obtain or consume products containing modafinil or armodafinil without medical supervision.

The authority said that these nine cases, involving seven men and two women aged between 18 and 57 years old, occurred between February 2024 and February 2025. There were three similar cases in a prior warning issued in November 2023.

They had reportedly obtained modafinil and armodafinil from street peddlers in Geylang or from their friends and consumed them as "supplements to boost energy and health".

Blistering and severe peeling of the skin

Six of the nine individuals developed Stevens-Johnson syndrome (SJS), a life-threatening skin condition characterised by blistering and severe peeling of the skin and mucous membranes, said HSA.

A man in his 40s also suffered from severe oral ulcers that prevented him from eating and speaking for a few days.

The other three individuals suffered a more severe form of SJS, toxic epidermal necrolysis (TEN). These people developed serious skin reactions and painful blistering rashes and peeling of skin that spread across the entire body.

A man in his 20s developed "life-threatening blistering of his skin" covering 60 per cent of his body, including his face, chest, arms, genitals, legs and the soles of his feet.

Most of the consumers are recovering and there are no mortalities, said HSA.

Strict medical supervision required

According to the HSA, modafinil and armodafinil are medicines that are not registered in Singapore. They are only available in some countries as prescription medicines for conditions such as narcolepsy, a condition that impairs the ability to sleep or stay awake.

These drugs are highly controlled due to the adverse effects that can develop. In addition to SJS and TEN, consumption of these drugs can cause heart problems, hypertension and psychiatric conditions such as anxiety, hallucinations or mania.

Modafinil and armodafinil also carry a potential risk of dependency due to their stimulant effects on the brain.

Organ failure can also result in severe cases of SJS and TEN, said Associate Professor Lee Haur Yueh, Senior Consultant, Department of Dermatology, Singapore General Hospital.

"The fact that we are seeing a significant number of cases from armodafinil and modafinil suggests that the risk associated with these medicines is particularly high," added Prof Lee.

Do not share or supply potent prescription medicines: HSA

HSA classifies modafinil and armodafinil as potent medicines which should be taken only with a doctor's prescription.

They advised consumers to seek medical advice and not to obtain medicines from illegal, unknown, unregistered or unreliable sources. 

"Do not share or supply potent prescription medicines to your friends or relatives, even if their medical conditions may appear similar to yours. The medicines may not be suitable or safe for them, and their medical condition may need to be assessed first and managed by a doctor," said HSA.

The illegal supply and sale of modafinil or armodafinil without HSA authorisation is an offence that carries a fine of up to $50,000 or jail term up to two years or both.

Individuals with any information on the illegal sale of modafinil or armodafinil can contact HSA's Enforcement Branch at 6866 3485 or email hsa_is@hsa.gov.sg.

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dana.leong@asiaone.com