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

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Bygg C
0473 Oslo

Tel:  +47 21 07 81 60

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A formulation approved both for use in the eye/ear is classified in S03, while formulations only licensed for use in the eye or the ear are classified in S01 and S02, respectively.


Most of the drugs in this group are topical preparations. Systemic preparations with clear ophthalmological indications are also classified in this group.
Small amounts of antiseptics in eye preparations do not influence the classification, e.g. benzalconium.
See also S03 - Ophthalmological and otological preparations.

DDDs have been assigned for antiglaucoma preparations only.


This group comprises preparations for local and systemic treatment of glaucoma.
Drugs used for producing miosis are classified in this group, even if the main indication is not glaucoma.

The DDDs are based on single dose (or single package) and administration frequencies. A single dose is defined as two eye drops (one in each eye) corresponding to 0.1 ml. For eye drops administered once daily the DDD is 0.1 ml, for eye drops administered twice daily the DDD is 0.2 ml, etc. For single use packages one dose is the volume of one package. This also applies for combinations. In eye ointments one dose corresponds to about 10 mm (20 mg) per eye thus corresponding to 40 mg for both eyes.

S01EA Sympathomimetics in glaucoma therapy

Preparations containing parasympathomimetics in combination with epinephrine, are classified in S01EB.

S01EB Parasympathomimetics

Combinations with beta blocking agents are classified in S01ED.

The DDD for pilocarpine lamellas has been obtained by dividing two lamellas by seven days (the recommended dose is 1 lamella/

S01EC Carbonic anhydrase inhibitors

Carbonic anhydrase inhibitors used for different indications are classified in this group.
Diclofenamide for treatment of periodic paralysis is classified here.

The DDDs are based on the average recommended doses in the treatment of chronic glaucoma.

S01ED Beta blocking agents

Combinations of beta blocking agents and other drugs, e.g. pilocarpine, are classified in this group, at separate 5th levels using the corresponding 50-series.

S01EE Prostaglandin analogues

Combinations with beta blocking agents are classified in S01ED.
Bimatoprost indicated for treatment of hypotrichosis of the eyelashes is classified here.

S01EX Other antiglaucoma preparations

Last updated: 2020-12-17