Nine hospitalised for serious skin reactions in the past year after using unregistered medicine to 'boost energy'

SINGAPORE: Nine people in Singapore were hospitalised for serious skin conditions over the past year after using unregistered medicines known as modafinil or armodafinil.

These are potent medicines that are not registered in Singapore but are available in some countries with a doctor's prescription for patients with specific medical conditions such as narcolepsy, a condition that impairs the ability to sleep or stay awake.

The nine patients - seven men and two women aged between 18 and 57 - were hospitalised between February 2024 and February 2025, the Health Sciences Authority (HSA) said on Monday (Mar 10).

They had obtained modafinil and armodafinil from street peddlers in Geylang or from their friends.

Some said they had taken these products to improve alertness or boost energy, said HSA. "One had taken them as 'supplements to boost energy and health,'" the agency added.

Six people developed Stevens-Johnson syndrome (SJS), a life-threatening skin condition characterised by blistering and severe peeling of the skin and mucous membrane.

One of them, a man in his 40s, also had severe oral ulcers that left him unable to eat and speak for a few days, HSA said.

The other three people suffered toxic epidermal necrolysis, a more severe form of SJS.

"They had serious skin reactions and developed painful blistering rashes and peeling of skin that spread across the entire body," said HSA.

"One of them, a male consumer in his 20s, experienced 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 affected consumers are recovering, with no deaths reported, HSA added.

HSA issued a similar warning in November 2023 after three people were hospitalised for serious adverse reactions from using these medicines inappropriately.

Besides serious skin conditions, modafinil and armodafinil could cause serious side effects such as heart problems and hypertension, as well as psychiatric conditions such as anxiety, hallucinations or mania.

The medicine also carries a potential risk of dependency due to its stimulant effects on the brain.

Associate Professor Lee Haur Yueh, a senior consultant at the department of dermatology at Singapore General Hospital said: "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."

Assoc Prof Lee, who treated some of the hospitalised consumers, added that the medicines should only be taken when prescribed by a doctor and with proper medical supervision.

The supply and sale of modafinil and armodafinil without HSA's authorisation is an offence under the Health Products Act. Offenders may face a jail term of up to two years, a fine of up to S$50,000 (US$35,550) or both.

Members of the public who have information on the illegal sale and supply of the medicines may contact HSA's enforcement branch at 68663485.