The drug giving rise to the adverse effect should be identified by use of codes from categories T36-T50 with fifth or sixth character 5.

Use Additional code(s) to specify:
manifestations of poisoning
underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
underdosing of medication regimen (Z91.12-, Z91.13-)

Code first   , for adverse effects, the nature of the adverse effect, such as:
  adverse effect NOS (T88.7)
  aspirin gastritis (K29.-)
  blood disorders (D56-D76)
  contact dermatitis (L23-L25)
  dermatitis due to substances taken internally (L27.-)
  nephropathy (N14.0-N14.2)

Includes:

  • adverse effect of correct substance properly administered
  • poisoning by overdose of substance
  • poisoning by wrong substance given or taken in error
  • underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed

Excludes1

  • toxic reaction to local anesthesia in pregnancy (O29.3-)

Excludes2

  • abuse and dependence of psychoactive substances (F10-F19)
  • abuse of non-dependence-producing substances (F55.-)
  • drug reaction and poisoning affecting newborn (P00-P96)
  • pathological drug intoxication (inebriation) (F10-F19)
  1. T40 Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens]

    Excludes2

    • drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.-F19.-)

    The appropriate 7th character is to be added to each code from category T40

    • A - initial encounter
    • D - subsequent encounter
    • S - sequela
    1. T40.0 Poisoning by, adverse effect of and underdosing of opium

      1. T40.0X Poisoning by, adverse effect of and underdosing of opium

    2. T40.1 Poisoning by and adverse effect of heroin

      1. T40.1X Poisoning by and adverse effect of heroin

    3. T40.2 Poisoning by, adverse effect of and underdosing of other opioids

      1. T40.2X Poisoning by, adverse effect of and underdosing of other opioids

        • T40.2X1 Poisoning by other opioids, accidental (unintentional)

          Inclusion term(s):

          • Poisoning by other opioids NOS
        • T40.2X2 Poisoning by other opioids, intentional self-harm
        • T40.2X3 Poisoning by other opioids, assault
        • T40.2X4 Poisoning by other opioids, undetermined
        • T40.2X5 Adverse effect of other opioids
        • T40.2X6 Underdosing of other opioids
    4. T40.3 Poisoning by, adverse effect of and underdosing of methadone

      1. T40.3X Poisoning by, adverse effect of and underdosing of methadone

        • T40.3X1 Poisoning by methadone, accidental (unintentional)

          Inclusion term(s):

          • Poisoning by methadone NOS
        • T40.3X2 Poisoning by methadone, intentional self-harm
        • T40.3X3 Poisoning by methadone, assault
        • T40.3X4 Poisoning by methadone, undetermined
        • T40.3X5 Adverse effect of methadone
        • T40.3X6 Underdosing of methadone
    5. T40.4 Poisoning by, adverse effect of and underdosing of other synthetic narcotics

      1. T40.4X Poisoning by, adverse effect of and underdosing of other synthetic narcotics

        • T40.4X1 Poisoning by other synthetic narcotics, accidental (unintentional)

          Inclusion term(s):

          • Poisoning by other synthetic narcotics NOS
        • T40.4X2 Poisoning by other synthetic narcotics, intentional self-harm
        • T40.4X3 Poisoning by other synthetic narcotics, assault
        • T40.4X4 Poisoning by other synthetic narcotics, undetermined
        • T40.4X5 Adverse effect of other synthetic narcotics
        • T40.4X6 Underdosing of other synthetic narcotics
    6. T40.5 Poisoning by, adverse effect of and underdosing of cocaine

      1. T40.5X Poisoning by, adverse effect of and underdosing of cocaine

    7. T40.6 Poisoning by, adverse effect of and underdosing of other and unspecified narcotics

      1. T40.60 Poisoning by, adverse effect of and underdosing of unspecified narcotics

        • T40.601 Poisoning by unspecified narcotics, accidental (unintentional)

          Inclusion term(s):

          • Poisoning by narcotics NOS
        • T40.602 Poisoning by unspecified narcotics, intentional self-harm
        • T40.603 Poisoning by unspecified narcotics, assault
        • T40.604 Poisoning by unspecified narcotics, undetermined
        • T40.605 Adverse effect of unspecified narcotics
        • T40.606 Underdosing of unspecified narcotics
      2. T40.69 Poisoning by, adverse effect of and underdosing of other narcotics

        • T40.691 Poisoning by other narcotics, accidental (unintentional)

          Inclusion term(s):

          • Poisoning by other narcotics NOS
        • T40.692 Poisoning by other narcotics, intentional self-harm
        • T40.693 Poisoning by other narcotics, assault
        • T40.694 Poisoning by other narcotics, undetermined
        • T40.695 Adverse effect of other narcotics
        • T40.696 Underdosing of other narcotics
    8. T40.7 Poisoning by, adverse effect of and underdosing of cannabis (derivatives)

      1. T40.7X Poisoning by, adverse effect of and underdosing of cannabis (derivatives)

        • T40.7X1 Poisoning by cannabis (derivatives), accidental (unintentional)

          Inclusion term(s):

          • Poisoning by cannabis NOS
        • T40.7X2 Poisoning by cannabis (derivatives), intentional self-harm
        • T40.7X3 Poisoning by cannabis (derivatives), assault
        • T40.7X4 Poisoning by cannabis (derivatives), undetermined
        • T40.7X5 Adverse effect of cannabis (derivatives)
        • T40.7X6 Underdosing of cannabis (derivatives)
    9. T40.8 Poisoning by and adverse effect of lysergide [LSD]

      1. T40.8X Poisoning by and adverse effect of lysergide [LSD]

        • T40.8X1 Poisoning by lysergide [LSD], accidental (unintentional)

          Inclusion term(s):

          • Poisoning by lysergide [LSD] NOS
        • T40.8X2 Poisoning by lysergide [LSD], intentional self-harm
        • T40.8X3 Poisoning by lysergide [LSD], assault
        • T40.8X4 Poisoning by lysergide [LSD], undetermined
    10. T40.9 Poisoning by, adverse effect of and underdosing of other and unspecified psychodysleptics [hallucinogens]

      1. T40.90 Poisoning by, adverse effect of and underdosing of unspecified psychodysleptics [hallucinogens]

        • T40.901 Poisoning by unspecified psychodysleptics [hallucinogens], accidental (unintentional)
        • T40.902 Poisoning by unspecified psychodysleptics [hallucinogens], intentional self-harm
        • T40.903 Poisoning by unspecified psychodysleptics [hallucinogens], assault
        • T40.904 Poisoning by unspecified psychodysleptics [hallucinogens], undetermined
        • T40.905 Adverse effect of unspecified psychodysleptics [hallucinogens]
        • T40.906 Underdosing of unspecified psychodysleptics [hallucinogens]
      2. T40.99 Poisoning by, adverse effect of and underdosing of other psychodysleptics [hallucinogens]

        • T40.991 Poisoning by other psychodysleptics [hallucinogens], accidental (unintentional)

          Inclusion term(s):

          • Poisoning by other psychodysleptics [hallucinogens] NOS
        • T40.992 Poisoning by other psychodysleptics [hallucinogens], intentional self-harm
        • T40.993 Poisoning by other psychodysleptics [hallucinogens], assault
        • T40.994 Poisoning by other psychodysleptics [hallucinogens], undetermined
        • T40.995 Adverse effect of other psychodysleptics [hallucinogens]
        • T40.996 Underdosing of other psychodysleptics [hallucinogens]
Abbreviations used here:

NEC Not elsewhere classifiable
This abbreviation in the Tabular List represents “other specified”. When a specific code is not available for a condition, the Tabular List includes an NEC entry under a code to identify the code as the “other specified” code.

NOS Not otherwise specified
This abbreviation is the equivalent of unspecified.