Australian drug regulator requires warning on Zolpidem

February 22, 2008

Australia's Therapeutic Goods Administration (TDC) will require makers of the sleeping pill, Zolpidem (marketed as Stilnox in Australia) to provide a warning about its "bizarre" and "potentially dangerous" side effects. The warning follows a decision by the National Drugs and Poisons Schedule Committee (NDPSC) not to reschedule the drug.

The NDPSC had considered changing zolpidem from a Schedule 4 drug to a Schedule 8 drug, which would have placed it in the same category as drugs like morphine and made it more difficult for doctors to prescribe. The NDPSC said zolpidem did not meet criteria to become a Schedule 8 drug because there was insufficient evidence to suggest a "substantial risk of abuse, dependence or misuse for illegal purposes".

The warning follows more than 1000 reports of the drug causing people to walk, drive, eat and have sex while they slept, among other suspected reactions. A TGA spokeswoman said the Adverse Medicine Events Line had also received 19 reports of deaths, most of them suicides, where the patient had been taking zolpidem.

The spokeswoman said coronial inquests on most of these deaths had found no link between the death and zolpidem.

The warning to be included on the Consumer Medical Information sheet inside the packaging will say that the drug "may be associated with potentially dangerous complex sleep-related behaviours … sleepwalking, sleep driving and other bizarre behaviours".

It will also warn patients not to mix zolpidem with alcohol or other Central Nervous System depressants and the drug should "limit use to four weeks maximum under close medical supervision".

Some patients have been prescribed the drug for a number of months, including 30-year-old Sydney woman Mairead Costigan, who fell to her death from the Sydney Harbour Bridge nearly six months ago. Costigan had been prescribed the drug for at least eight months, but just six days before her death she switched to another sleeping pill (zopiclone).

Ms Costigan's sister Siobhan said her family was disappointed but was not surprised by the TGA's decision.

"I understand that the committee received well over 100 submissions from members of the public who have been adversely affected or lost loved ones," she said.

Independent ACT politician and staunch opponent of the drug, Helen Cross said that after being prescribed zolpidem, she became addicted to it and tried to commit suicide three times. In one case, she sent friends a text message saying "goodbye" without remembering anything about the incident when police arrived to rescue her.

While prescription information for the drug says it can increase depression and that "suicidal tendencies may be present", Ms Cross says doctors who prescribed the drug did not warn her about these side effects.

A spokeswoman for the drug's manufacturer, Sanofi-Aventis said it supported the TGA's decision.

The criticism was a "largely Australian-specific phenomenon and in our view does not accurately reflect [its] safety profile", she said.