SINGAPORE — Members of the public are advised against consuming modafinil, a potent prescription drug that is not registered locally.

This comes after a woman in her 30s was hospitalised and diagnosed with a life-threatening skin condition after consuming the drug to raise her alertness as she had to work long hours.

In a press release on Tuesday (Feb 6), the Health Sciences Authority (HSA) said the woman had obtained the product from her friend and had been consuming it on alternate days for over three weeks.

She first developed an itchy rash which then spread to the whole body. This was followed by severe peeling of the skin, a painful throat, multiple mouth ulcers and conjunctivitis (red eyes). The woman was later diagnosed with Stevens-Johnson syndrome.

Modafinil is available in some countries as a prescription drug that reduces excessive sleepiness associated with specific medical conditions such as narcolepsy. These patients experience excessive daytime sleepiness and a tendency to fall asleep suddenly in inappropriate situations.

The health authority noted that there have been reports of people taking modafinil for the purposes of improving alertness or as cognitive enhancers to improve focus and memory.

It added that self-medication with modafinil for these purposes “is not appropriate and can be harmful”.

“Due to the stimulant effects it has on the brain, modafinil carries a potential risk of dependency,” said the HSA.

“It can also cause serious side effects such as heart problems, hypertension, and psychiatric conditions such as anxiety, hallucinations or mania.”

Besides the Stevens-Johnson syndrome, those who consume the drug could also develop a condition called toxic epidermal necrolysis, where more than 30 per cent of the skin is affected.

These conditions can lead to hospitalisation, serious complications or even death, said the HSA. Those who recover may experience long-term side effects such as skin scarring, and visual impairment including blindness.

The health authority also warned consumers to be cautious when obtaining or purchasing health products from unfamiliar sources, even if they are recommended by friends or relatives.

It added that consumers should not share or supply potent western medicines to friends or relatives, even if they have similar medical conditions, “as their medical condition may need to be managed by a doctor”.

Unless authorised by the HSA for use in special circumstances by a doctor for patients under his care, the supply and sale of an unregistered health product such as modafinil is an offence under the Health Products Act.

If convicted, the person can face a fine up to S$50,000 or jail term up to two years or both.

"All medicines are required to be evaluated and registered by HSA before they can be supplied in Singapore," said a HSA spokesperson. "This is to ensure that medicines used in our patients meet the required quality, safety and efficacy standard, and that the benefit of the treatment outweighs the risk of side effects.

"In a situation where there is an unmet medical need, such as where none of the registered medicine is effective or suitable for the treatment of a patient, and after careful assessment of the patient’s medical condition and the suitability of the treatment, a doctor may seek permission from HSA to bring in an unregistered medicine for the treatment of the patient under his care. 

"Unregistered medicines are not evaluated by HSA for quality, efficacy and safety; the doctor who decides to use an unregistered medicine on his patient will have to assume full responsibility on its use."

Members of the public who have any information on the sale and supply of modafinil from unauthorised sources may contact HSA’s Enforcement Branch at Tel: 6866-3485 during office hours (Monday to Friday) or email: hsa_is [at] hsa.gov.sg.