Estazolam

What estazolam is and how it works

Estazolam is a prescription benzodiazepine medicine used for the short-term treatment of insomnia (trouble falling asleep, waking during the night, or waking too early). It was originally sold as ProSom in the US and Canada, but that brand has been discontinued in both countries; it is currently available as a generic medicine in the United States and as Nuctalon in France. (1)

Estazolam carries a genuine, current boxed warning -- the FDA's strongest safety warning -- covering three real risks: dangerous, potentially fatal breathing problems if combined with opioids; risk of abuse, misuse, and addiction; and risk of physical dependence with life-threatening withdrawal reactions if stopped abruptly or the dose is reduced too quickly. Because of these risks, estazolam is intended for short-term use (evidence supports up to 12 weeks), and any change in dose or plan to stop must always be made together with your prescriber -- never on your own.

Mechanism of action: how estazolam works

Estazolam is a triazolobenzodiazepine CNS depressant. It is extensively metabolised via CYP3A to 4-hydroxy-estazolam (the major metabolite) and other metabolites, with an elimination half-life of about 10-24 hours (mean approximately 18.4 hours in elderly patients), and is primarily excreted renally. (1)

What estazolam is used for

Before taking estazolam

Do not take / not appropriate for

• Do not take estazolam if you have had a hypersensitivity (allergic) reaction to estazolam or any other benzodiazepine. (all countries where authorised) (1)
• Do not take estazolam together with ketoconazole or itraconazole (strong interactions that significantly raise estazolam levels). (United States) (1)

Tell your clinician about

• Whether you are pregnant, planning to become pregnant, or breastfeeding.
• Any history of depression or suicidal thoughts.
• Any history of substance use disorder, or alcohol use.
• Any breathing problems, including sleep apnoea.
• All other medicines you take, especially opioids, other sedatives, antifungal medicines (ketoconazole, itraconazole), and other medicines that affect CYP3A liver enzymes.
• Whether you have ever had a serious allergic reaction (angioedema) to estazolam or another benzodiazepine.
• Whether you smoke, since smoking can change how quickly your body clears this medicine.

How to take estazolam

• Take estazolam exactly as your prescriber directs, usually at bedtime.
• Only take estazolam if you are able to get a full night's sleep before you need to be active again.
• Do not stop taking estazolam or change your dose without talking to your prescriber -- if you and your prescriber decide to stop, this is normally done with a gradual, prescriber-supervised taper, not all at once, because of the real risk of withdrawal.
• Tell your prescriber right away if you experience 'sleep-driving' or other activities (such as preparing food, making phone calls, or having sex) that you do not remember doing -- this is a genuine, recognised risk, especially if combined with alcohol or other sedating medicines.
• Avoid alcohol while taking estazolam, and avoid activities requiring full mental alertness, such as driving, until you know how the medicine affects you.

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

Estazolam is taken as needed at bedtime for sleep, not on a fixed daily schedule in the same way as most medicines -- only take it when you are able to get a full night's sleep. If you have questions about your specific dosing schedule, ask your pharmacist or prescriber.

Overdose

Seek emergency medical attention immediately if too much estazolam has been taken, especially if combined with alcohol or other sedating medicines, which can be fatal. Symptoms can range from drowsiness and confusion to coma. There is a reversal medicine (flumazenil) that a medical team can consider, but it carries its own risks, including seizures, particularly after long-term benzodiazepine use. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Serious warnings

Interactions

• Opioid pain medicines significantly increase the risk of profound sedation, breathing problems, and death when combined with estazolam. (1)
• Ketoconazole and itraconazole (antifungal medicines) significantly raise estazolam levels and should not be combined with it. (1)
• Other CYP3A-affecting medicines -- such as nefazodone, fluvoxamine, cimetidine, diltiazem, isoniazid, and macrolide antibiotics -- can raise estazolam levels and should be used cautiously together. (1)
• Alcohol, other sedatives, anticonvulsants, antihistamines, and other psychotropic medicines can increase drowsiness and sedation when combined with estazolam. (1)
• Smoking can speed up how quickly estazolam is cleared from the body, potentially reducing its effect. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Monitoring

Before starting

• Review of other medicines, especially opioids and antifungal medicines
• Assessment of substance-use and mental-health history
• Discussion of realistic treatment duration (short-term use)

During treatment

• Regular review of whether continued use is still needed, since estazolam is intended for short-term use.
• Watching for signs of sleep-driving or other complex sleep behaviours.
• Watching for signs of low mood or suicidal thoughts.
• Any planned dose reduction or stopping done gradually and under prescriber supervision.

Storage

Store at controlled room temperature, 20-25degC (68-77degF), in a tight, light-resistant container, out of reach of children and anyone for whom it was not prescribed.

Frequently asked questions

References

1. ESTAZOLAM tablet, USP (C-IV) -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information (generic estazolam, Teva/Watson, ANDA 074818) · United States · accessed 2026-07-30 · source 1
2. ACMD review of novel benzodiazepines -- estazolam listed among benzodiazepines not licensed as medicines in the UK, separately controlled as Class CUK Advisory Council on the Misuse of Drugs (ACMD), a statutory UK government advisory body, plus general web-search corroboration · United Kingdom · accessed 2026-07-30 · source 2
3. NUCTALON (estazolam) -- HAS opinion (renewal of registration/reassessment, 25 June 2014) and French drug-reference listingsHaute Autorite de Sante (HAS), France -- Transparency Committee opinion, plus VIDAL/Sante.fr French drug-reference corroboration · European Union (France) · accessed 2026-07-30 · source 3
4. PROSOM (estazolam) 2 mg tablet -- Drug Product Database entry, status Cancelled Post MarketHealth Canada Drug Product Database · Canada · accessed 2026-07-30 · source 4
5. Estazolam -- Office of Drug Control controlled-substances listing; not registered for therapeutic use in AustraliaAustralian Government Office of Drug Control (ODC), plus TGA ARTG search corroboration · Australia · accessed 2026-07-30 · source 5
6. No Medsafe New Zealand Data Sheet located for estazolamMedsafe, New Zealand -- absence of a located Data Sheet · New Zealand · accessed 2026-07-30 · source 6

Brand names by country

Single-ingredient estazolam names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries