Zolpidem (Ambien / Myslee)

What is zolpidem?

Zolpidem is known as Ambien in the United States and Myslee in Japan (マイスリー on Japanese packaging), and as Stilnoct in some European countries; in the UK it is usually prescribed under its generic name. It's all the same medicine. It belongs to the "Z-drug" (non-benzodiazepine) group of sleep medicines: it calms the brain's activity at night so you can fall asleep more easily, and it's meant as short-term help while sleep settles.

How is it different from other sleeping pills?

• Works from the first night: no build-up period, unlike antidepressants, which take weeks
• Made for falling asleep: the Japanese label classes it as a medicine for getting to sleep rather than for staying asleep
• Short-acting: it is absorbed quickly, and most of it has left your system by morning
• Keeps the shape of sleep: in studies in healthy adults it increased deep sleep without affecting dream (REM) sleep

What is it used for in Japan?

Insomnia: mainly difficulty falling asleep. (The Japanese approval excludes insomnia that comes with schizophrenia or bipolar disorder, where different treatment is used.)

What it targets: the start of the night. It's short-acting, so it suits trouble falling asleep rather than waking in the middle of the night.

How does it help?

It quietens the brain's activity at night so you can fall asleep more easily. It works fast, so it's taken right before bed, and it works best as a short bridge alongside good sleep habits.

What should I tell my doctor before starting?

A few situations rule it out entirely; your doctor will choose something else if any of these apply:

• A past allergic reaction to zolpidem
• Serious liver problems
• Myasthenia gravis (a muscle-weakness condition)
• Acute narrow-angle glaucoma
• A previous episode of acting out in your sleep (sleepwalking and the like) on this medicine

And tell your doctor first if any of these apply; these usually just need adjustments or a closer eye:

• Severely reduced lung function (for example from emphysema or asthma): the label says it is not given in that case unless there is no alternative
• Milder liver problems, or kidney problems
• A heart condition
• Other sedating medicines, or regular alcohol use
• Being older: a lower dose is used
• Pregnant, planning to be, or breastfeeding (see the section below)

How do I take it?

Only right before bed, and only on nights you can give a full night to sleep.

• Take it immediately before lying down, not earlier in the evening
• Don't take it if you might need to get up and function during the night
• If you forget it, don't take it in the middle of the night; just skip that night. Never take a second dose in one night
• Avoid alcohol as far as possible; the Japanese label asks for this because the two add to each other's effects on alertness and coordination
• Older adults start at a lower dose

What side effects should I expect?

Most are mild. Not everyone gets them.

• Unsteadiness, drowsiness, or dizziness: watch your footing, especially at night
• A "hangover" or leftover sleepiness the next morning
• Headache
• Nausea

If anything is bothering you, tell your doctor; there's often a way to adjust.

Finally, one thing that is rare (most people never experience it) but good to know:

• Very occasionally, people carry out activities while not fully awake (walking, eating, even driving) with no memory of it afterwards. If you or someone around you notices this, stop the medicine and tell us; the Japanese label says zolpidem is not given again after this, and a different type of sleep medicine is used instead

Will I become dependent? How do I stop safely?

It can be habit-forming with regular long-term use, so it's used short term, at the lowest dose that works, and stopped with a plan. The Japanese label warns against continuing it for a long time without a clear reason. The body can come to rely on it, and stopping suddenly after regular use can bring a few nights of rebound poor sleep and irritability, so never stop suddenly on your own; your doctor lowers it gradually or shifts to as-needed use. The aim is a short bridge while sleep recovers, and your doctor will revisit whether it's still needed.

Can I bring it into Japan?

Yes, within limits, because it's a controlled medicine here. Zolpidem is a scheduled (psychotropic) medicine in Japan: a personal supply of roughly up to a month travels with you without advance permission (keep it in the original packaging with your prescription), larger amounts need an advance import certificate, and mailing it to Japan is prohibited. It also cannot be prescribed online, at a first visit or a follow-up, until a doctor in Japan has examined you in person for the sleep problem, so plan an in-person visit. One more note: the extended-release form (Ambien CR) isn't sold in Japan; the standard tablets are.

Can I drive while taking it?

No. Don't drive after taking it, and be alert to leftover drowsiness the next morning. Because the effect can carry into the next day, the Japanese label instructs that patients on zolpidem should not drive or operate dangerous machinery. If next-morning sleepiness keeps happening, tell your doctor; the dose or the medicine can be changed.

What about pregnancy and breastfeeding?

Tell your doctor early; this one is planned case by case. The Japanese label allows zolpidem in pregnancy only when the benefit is judged to outweigh the risk, and notes that babies exposed to it late in pregnancy can show withdrawal symptoms after birth. With breastfeeding, zolpidem is avoided: it passes into milk and can make the baby drowsy. Don't start, stop, or continue on your own; our guides to medication in pregnancy and medication while breastfeeding cover the wider picture.