Sleep medication linked to bizarre behaviour

12:44 06 February 2007

Roxanne Khamsi

New evidence has linked a commonly prescribed sleep medication with

bizarre behaviours, including a case in which a woman painted her front

door in her sleep.

UK and Australian health agencies have

released information about 240 cases of odd occurrences, including

sleepwalking, amnesia and hallucinations among people taking the drug

zolpidem.

While doctors say that zolpidem can offer much-needed

relief for people with sleep disorders, they caution that these newly

reported cases should prompt a closer look at its possible side effects.

Zolpidem, sold under the brand names Ambien, Stilnoct and Stilnox, is

widely prescribed to treat insomnia and other disorders such as sleep

apnea. Various forms of the drug, made by French pharmaceutical giant

Sanofi-Aventis, were prescribed 674,500 times in 2005 in the UK.

A newly published report from Australia’s Federal Health Department

describes 104 cases of hallucinations and 62 cases of amnesia

experienced by people taking zolpidem since marketing of the drug began

there in 2000. The health department report also mentioned 16 cases of

strange sleepwalking by people taking the medication.

Midnight snack

In one of these sleepwalking cases a patient woke with a paintbrush in

her hand after painting the front door to her house. Another case

involved a woman who gained 23 kilograms over seven months while taking

zolpidem. “It was only when she was discovered in front of an open

refrigerator while asleep that the problem was resolved,” according to

the report.

The UK’s Medicines and Healthcare products

Regulatory Agency, meanwhile, has recorded 68 cases of adverse reactions

to zolpidem from 2001 to 2005.

The newly reported cases in the

UK and Australia add to a growing list of bizarre sleepwalking episodes

linked to the drug in other countries, including reports of people

sleep-driving while on the medication. In one case, a transatlantic

flight had to be diverted after a passenger caused havoc after taking

zolpidem.

Hypnotic effects

There is no biological

pathway that has been proven to connect zolpidem with these behaviours.

The drug is a benzodiazepine-like hypnotic that promotes deep sleep by

interacting with brain receptors for a chemical called

gamma-aminobutyric acid. While parts of the brain become less active

during deep sleep, the body can still move, making sleepwalking a

possibility.

The product information for prescribers advises

that psychiatric adverse effects, including hallucinations, sleepwalking

and nightmares, are more likely in the elderly, and treatment should be

stopped if they occur.

Patient advocacy groups say they would

like government health agencies and drug companies to take a closer look

at the possible risks associated with sleep medicines. They stress that

strange sleepwalking and sleep-driving behaviours can have risky

consequences.

“When people do something in which they’re not in

full control it’s always a danger,” says Vera Sharav of the New

York-based Alliance for Human Research Protection, a US network that

advocates responsible and ethical medical research practices.

Tried and tested

“The more reports that come out about the potential side effects of the

drug, the more research needs to be done to understand if these are

real side effects,” says sleep researcher Kenneth Wright at the

University of Colorado in Boulder, US.

Millions of people have

taken the drug without experiencing any strange side effects, points out

Richard Millman at Brown Medical School, director of the Sleep

Disorders Center of Lifespan Hospitals in Providence, Rhode Island, US.

He says that unlike older types of sleep medications, zolpidem does not

carry as great a risk of addiction.

And Wright notes that some

of the reports of “sleep-driving” linked to zolpidem can be easily

explained: some patients have wrongly taken the drug right before

leaving work in hopes that the medicine will kick in by the time they

reach home. Doctors stress that the medication should be taken just

before going to bed.

The US Food & Drug Administration says

it is continuing to "actively investigate" and collect information about

cases linking zolpidem to unusual side effects.

The Ambien

label currently lists strange behaviour as a “special concern” for

people taking the drug. “It’s a possible rare adverse event,” says

Sanofi-Aventis spokesperson Melissa Feltmann, adding that the strange

sleepwalking behaviours “may not necessarily be caused by the drug” but

instead result from an underlying disorder. She says that “the safety

profile [of zolpidem] is well established”. The drug received approval

in the US in 1993.

Questions 1-6

Do the following statements agree with the information given in the reading passage?

In boxes 1-6 on your answer sheet write

TRUE if the statement is true according to the passage

FALSE if the statement is false according to the passage

NOT GIVEN if the information is not given in the passage

1. Ambien, Stilnoct and Stilnox are brand names of one same drug treating insomnia.

2. The woman’s obesity problem wasn’t resolved until she stopped taking zolpidem.

3. Zolpidem received approval in the UK in 2001.

4. The bizarre behaviour of a passenger after taking zolpidem resulted

in the diversion of a flight bound for the other side of the Atlantic.

5. Zolpidem is the only sleep medication that doesn’t cause addiction.

6. The sleep-driving occurrence resulted from the wrong use of zolpidem by an office worker.

Question 7-9

Choose the appropriate letters A-D and Write them in boxes 7-9 on your answer sheet.

7. How many cases of bizarre behaviours are described in an official report from Australia?

A. 68

B. 104

C. 182

D. 240

8. Which of the following is NOT mentioned in the product information about zolpidem?

A. Treatment should be stopped if side effects occur.

B. Medication should be taken just before going to bed.

C. Adverse effects are more likely in the elderly.

D. Side effects include nightmares, hallucinations and sleepwalking.

9. Who claimed that the safety description of zolpidem was well established?

A. Kenneth Wright

B. Melissa Feltmann

C. Richard Millman

D. Vera Sharav

Questions 10-13

Answer the following questions with NO MORE THAN THREE WORDS each in boxes 10-13.

10. How many times was French-made zolpidem prescribed in 2005 in Britain?

11. What kind of hypnotic is zolpidem as a drug which promotes deep sleep in patients?

12. What can sleepwalking and sleep-driving behaviours cause according to patient advocacy groups?

13. What US administration says that it has been investigating the cases relating zolpidem to unusual side effects?

Answer keys and explanations:

1. True

See para.3 from the beginning: Zolpidem, sold under the brand names

Ambien, Stilnoct and Stilnox, is widely prescribed to treat insomnia and

other disorders such as sleep apnea.

2. False

See

para.1 under the subtitle “Midnight snack”: Another case involved a

woman who gained 23 kilograms over seven months while taking zolpidem.

“It was only when she was discovered in front of an open refrigerator

while asleep that the problem was resolved”…

3. Not Given

See para.2 under the subtitle “Midnight snack”: The UK’s Medicines and

Healthcare products Regulatory Agency, meanwhile, has recorded 68 cases

of adverse reactions to zolpidem from 2001 to 2005. (The time the drug

was approved in the UK was not mentioned.)

4. True

See

para.3 under the subtitle “Midnight snack”: In one case, a transatlantic

flight had to be diverted after a passenger caused havoc after taking

zolpidem.

5. False

See para.2 under the subtitle “Tried

and tested”: He says that unlike older types of sleep medications,

zolpidem does not carry as great a risk of addiction.

6. Not Given

See para.3 under the subtitle “Tried and tested”: And Wright notes that

some of the reports of “sleep-driving” linked to zolpidem can be easily

explained: some patients have wrongly taken the drug right before

leaving work in hopes that the medicine will kick in by the time they

reach home. (No patients as office workers are mentioned in the

passage.)

7. C

See para.4 from the beginning: A newly

published report from Australia’s Federal Health Department describes

104 cases of hallucinations and 62 cases of amnesia experienced by

people taking zolpidem since marketing of the drug began there in 2000.

The health department report also mentioned 16 cases of strange

sleepwalking by people taking the medication.

8. B

See

the sentence in para.2 under the subtitle “Hypnotic effects” (The

product information for prescribers advises that psychiatric adverse

effects, including hallucinations, sleepwalking and nightmares, are more

likely in the elderly, and treatment should be stopped if they occur.)

and the sentence in para.3 under the subtitle “Tried and tested”

(Doctors “not the product information” stress that the medication should

be taken just before going to bed.)

9. B

See para.5

under the subtitle “Tried and tested”: Sanofi-Aventis spokesperson

Melissa Feltmann … says that “the safety profile [of zolpidem] is well

established”.

10. 674,500 (times)

See para.3 from the

beginning: Various forms of the drug, made by French pharmaceutical

giant Sanofi-Aventis, were prescribed674,500 times in 2005 in the UK.

11. (a) benzodiazepine-like (hypnotic)

See para.1 under the subtitle “Hypnotic effects”: The drug is a

benzodiazepine-like hypnotic (類苯二氮催眠藥)that promotes deep sleep by

interacting with brain receptors for a chemical called

gamma-aminobutyric acid.

12. risky consequences

See

para.3 under the subtitle “Hypnotic effects”: Patient advocacy groups …

stress that strange sleepwalking and sleep-driving behaviours can have

risky consequences.

13. Food & Drug (Administration)

See para.4 under the subtitle “Tried and tested”: The US Food &

Drug Administration says it is continuing to "actively investigate" and

collect information about cases linking zolpidem to unusual side

effects.