A ALIMENTARY TRACT AND METABOLISM

 B BLOOD AND BLOOD FORMING ORGANS

 C CARDIOVASCULAR SYSTEM

 D DERMATOLOGICALS

 G GENITO URINARY SYSTEM AND SEX HORMONES

 H SYSTEMIC HORMONAL PREPARATIONS, EXCL. SEX HORMONES AND INSULINS

 J ANTIINFECTIVES FOR SYSTEMIC USE

 L ANTINEOPLASTIC AND IMMUNOMODULATING AGENTS

 M MUSCULO-SKELETAL SYSTEM

 N NERVOUS SYSTEM

   N01 ANESTHETICS

   N02 ANALGESICS

     N02A OPIOIDS

       N02AA Natural opium alkaloids

       N02AB Phenylpiperidine derivatives

       N02AC Diphenylpropylamine derivatives

       N02AD Benzomorphan derivatives

       N02AE Oripavine derivatives

         N02AE01 Buprenorphine [DG:DG00820]

       N02AF Morphinan derivatives

       N02AG Opioids in combination with antispasmodics

       N02AJ Opioids in combination with non-opioid analgesics

       N02AX Other opioids

     N02B OTHER ANALGESICS AND ANTIPYRETICS

     N02C ANTIMIGRAINE PREPARATIONS

   N03 ANTIEPILEPTICS

   N04 ANTI-PARKINSON DRUGS

   N05 PSYCHOLEPTICS

   N06 PSYCHOANALEPTICS

   N07 OTHER NERVOUS SYSTEM DRUGS

     N07A PARASYMPATHOMIMETICS

     N07B DRUGS USED IN ADDICTIVE DISORDERS

       N07BA Drugs used in nicotine dependence

       N07BB Drugs used in alcohol dependence

       N07BC Drugs used in opioid dependence

         N07BC01 Buprenorphine [DG:DG00820]

         N07BC02 Methadone [DG:DG00999]

         N07BC03 Levacetylmethadol [DG:DG01000]

         N07BC04 Lofexidine [DG:DG01001]

         N07BC05 Levomethadone [DG:DG01002]

         N07BC06 Diamorphine [DG:DG01003]

         N07BC51 Buprenorphine, combinations

     N07C ANTIVERTIGO PREPARATIONS

     N07X OTHER NERVOUS SYSTEM DRUGS

 P ANTIPARASITIC PRODUCTS, INSECTICIDES AND REPELLENTS

 R RESPIRATORY SYSTEM

 S SENSORY ORGANS

 V VARIOUS