Postal address:
WHO Collaborating Centre for Drug Statistics Methodology
Norwegian Institute of Public Health
Postboks 222 Sk°yen
0213 Oslo

Visiting/delivery address:
Sandakerveien 24C
Bygg C
0473 Oslo

Tel:  +47 21 07 81 60

New search    Hide text from Guidelines


The group is divided into therapeutic subgroups:
N05A - Antipsychotics
N05B - Anxiolytics
N05C - Hypnotics and sedatives


This group comprises preparations with mainly sedative or hypnotic actions.
Melatonin receptor agonists are also classified in this group.
See also:
N05A - Antipsychotics
N05B - Anxiolytics
R06A - Antihistamines for systemic use
Combined preparations are classified at separate 4th levels, N05CB and N05CX.
Regarding classification of combined preparations, see comments under N05B - Anxiolytics.
Combined preparations with barbiturates are mainly classified in A03 (mainly antispasmodic effect) or in N02 (mainly analgesic effect).
Combined preparations with barbiturates which remain in N05C are mainly "neurostabilizers".
The group is subdivided according to chemical structure.

The DDDs are based on use of the drugs as hypnotics.
The DDD for melatonin is based on dose recommendations in EU for the 2 mg depot tablet.

N05CA Barbiturates, plain

This group comprises barbiturates used for insomnia.
Preparations used as premedication are also classified in this group.
Barbiturates used in general anesthesia are classified in N01A - General anesthetics.
Barbiturates used mainly in the treatment of epilepsy, e.g. phenobarbital, are classified in N03 - Antiepileptics.
Combined preparations are classified in N05CB, see comment under N05C.

N05CB Barbiturates, combinations

This group comprises combined preparations with mainly sedative action. Combinations with analgesics etc., see comments under N05C - Hypnotics and sedatives.
Tetrabamate is classified here.

N05CC Aldehydes and derivatives
N05CD Benzodiazepine derivatives

Benzodiazepine derivatives used mainly in sleeping disorders are classified in this group.
All midazolam medicinal products are classified here.
See also N05BA.

The DDDs for nasal and sublingual formulations (oromucosal administration) of midazolam are based on acute treatment of seizures in patients with epilepsy.

N05CE Piperidinedione derivatives
N05CF Benzodiazepine related drugs
N05CH Melatonin receptor agonists

The DDD for melatonin is based on dose recommendations for the 2 mg depot tablet approved in Europe.

N05CM Other hypnotics and sedatives

This group includes drugs, which cannot be classified in the preceding groups.

N05CX Hypnotics and sedatives in combination, excl. barbiturates

All combination products mainly used in sleeping disorders are classified in this group, except combinations with barbiturates, see N05CB.

Last updated: 2021-12-14