Psychiatrist Ang Yong Guan suspended for overprescribing medication to patient who later died

Psychiatrist Ang Yong Guan, who has been practising medicine for more than 36 years, has been handed a three-year suspension over numerous prescriptions he made to a patient – prescriptions that deviated from relevant guidelines.

Dr Ang is also the assistant secretary-general of the Progress Singapore Party (PSP) and contested the Mary­mount seat in the 2020 General Election.

The suspension was handed down by the Court of Three Judges in a written judgment on Feb 5. The court had, in May 2024, found Dr Ang guilty of three charges of professional misconduct.

The most serious charge relates to the last prescription issued to the patient, which entailed a dramatic one-off increase in the dosages of two drugs well beyond the stated maximum limits.

The patient, Mr Quek Kiat Siong, who was then 50, died four days after this prescription was issued in 2012.

The cause of death was certified as “multi-organ failure with pulmonary haemorrhage, due to mixed drug intoxication”.

The final prescription was for a daily dosage of 60mg of antidepressant medication mirtazapine and 25mg of a controlled-release form of zolpidem, which is used to treat insomnia.

The permitted maximum daily dosage of the two drugs is 45mg and 12.5mg, respectively.

The other two charges relate to prescriptions issued between Feb 8, 2010, and July 31, 2012.

It was not disputed that Dr Ang had deviated from Ministry of Health guidelines issued in 2008 by concurrently prescribing two or more benzodiazepines to the patient.

He had also prescribed benzodiazepines despite being aware that the patient was concurrently taking opioid painkillers, which goes against the manufacturers’ recommendations.

The psychiatrist’s lawyer, Mr Christopher Chong, had argued for a suspension period of three months.

Mr Edmund Kronenburg, the lawyer for the Singapore Medical Council (SMC), had sought a three-year suspension.

Even though the SMC did not accuse­ Dr Ang of actually causing the patient’s death, the court said it was entitled to take the death into account in concluding that the final prescription entailed “grave risks”.

The judges said that in determining the level of harm, they could not ignore the fact that the patient’s cause of death was found to have resulted from the combination of multiple drugs, whose prescription Dr Ang was unable to justify.

They highlighted Dr Ang’s own concession that 60mg of mirtazapine per night was at the “edge of the killing range”. 

The judges said even if they accepted that Dr Ang genuinely believed it necessary to go outside the bounds of accepted standards of treatment for the patient to live a normal life, it was difficult to excuse his failure to inform Mr Quek of the real and severe risk that the treatment could end his life altogether. 

“It is simply not for a doctor to dice with the life of a patient on the patient’s behalf, especially where the risks inherent in a course of treatment are as significant as in the present case, no matter how well-intentioned or justifiable the doctor thinks that it is worth the gambit.”

Dr Ang’s failure to inform the patient of the risks thus increased his blameworthiness, the court said.

The judges also considered Dr Ang’s seniority and specialist status as an aggravating factor.

They noted that Dr Ang was highly regarded in the profession, even in comparison with other senior doctors.

Dr Ang’s seniority lay not only with his number of years in the profession but also his stature – he had held prominent positions, including as president of the Singapore Psychiatric Association. 

“With great position comes great responsibility, and we agree with Mr Kronenburg that there is greater erosion of public confidence in the medical profession when some­one of Dr Ang’s stature misconducts himself,” the court said.

The commencement date of the suspension period will be stipulated by the court in seven days, unless the parties write in with their respective proposals.

Dr Ang, who runs his own practice, Ang Yong Guan Psychiatry, began treating Mr Quek on Feb 8, 2010, for various conditions, including insomnia, depression, post-traumatic stress disorder, obsessional ruminations and anxiety.

His final prescription was issued on July 31, 2012, four days before Mr Quek died on Aug 4 that year.

After Mr Quek’s death, his sister sued his insurers, who denied liability under two personal accident policies.

She argued that he had died as a result of accidental drug interactions, but the insurer denied that the death was accidental.

In 2017, the Court of Appeal ruled in favour of Ms Quek and ordered the insurers to pay out the sums under the policies. The court found that the most likely scenario was that Mr Quek had taken his medication as prescribed.

Ms Quek then filed a complaint with the SMC against Dr Ang in April 2017.

The SMC brought three charges of professional misconduct against Dr Ang.

A disciplinary tribunal acquitted Dr Ang of professional misconduct and instead handed down a two-year suspension for failing to provide professional services of the quality that is reasonably expected of him.

Both Dr Ang and the SMC appealed against the tribunal’s decision.

In May 2024, the Court of Three Judges overturned the tribunal’s decision and found Dr Ang guilty of professional misconduct.

In a statement on Feb 5, the PSP said Dr Ang will not contest in the next general election.

The PSP added that it accepted the Court of Appeal’s decision to suspend Dr Ang and that he had informed the party that he would not seek re-election to its central executive committee or participate in the general election, which must be held by November 2025.

In the 2020 General Election, Dr Ang contested the newly formed Marymount SMC, where he lost to Minister of State for Education and Manpower Gan Siow Huang.

Ms Gan won with 55.04 per cent of the vote.

Source: The Straits Times © SPH Media Limited. Permission required for reproduction.

Dr Ang Yong Guan v Singapore Medical Council [2025] SGHC 17

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