2024 ICD-10-CM Diagnosis Code T43.3X6A

Underdosing of phenothiazine antipsychotics and neuroleptics, initial encounter

ICD-10-CM Code:
T43.3X6A
ICD-10 Code for:
Underdosing of phenothiazine antipsychot/neurolept, init
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    (S00–T88)
    • Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
      (T36-T50)
      • Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified
        (T43)

T43.3X6A is a billable diagnosis code used to specify a medical diagnosis of underdosing of phenothiazine antipsychotics and neuroleptics, initial encounter. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

This code describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.

T43.3X6A is an initial encounter code, includes a 7th character and should be used while the patient is receiving active treatment for a condition like underdosing of phenothiazine antipsychotics and neuroleptics. According to ICD-10-CM Guidelines an "initial encounter" doesn't necessarily means "initial visit". The 7th character should be used when the patient is undergoing active treatment regardless if new or different providers saw the patient over the course of a treatment. The appropriate 7th character codes should also be used even if the patient delayed seeking treatment for a condition.

Clinical Classification

Clinical Information

  • Acepromazine

    a phenothiazine that is used in the treatment of psychoses.
  • Chlorpromazine

    the prototypical phenothiazine antipsychotic drug. like the other drugs in this class chlorpromazine's antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking dopamine receptors. chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup.
  • Fluphenazine

    a phenothiazine used in the treatment of psychoses. its properties and uses are generally similar to those of chlorpromazine.
  • Mesoridazine

    a phenothiazine antipsychotic with effects similar to chlorpromazine.
  • Methotrimeprazine

    a phenothiazine with pharmacological activity similar to that of both chlorpromazine and promethazine. it has the histamine-antagonist properties of the antihistamines together with central nervous system effects resembling those of chlorpromazine. (from martindale, the extra pharmacopoeia, 30th ed, p604)
  • Perazine

    a phenothiazine antipsychotic with actions and uses similar to those of chlorpromazine. extrapyramidal symptoms may be more common than other side effects.
  • Perphenazine

    an antipsychotic phenothiazine derivative with actions and uses similar to those of chlorpromazine.
  • Prochlorperazine

    a phenothiazine antipsychotic used principally in the treatment of nausea; vomiting; and vertigo. it is more likely than chlorpromazine to cause extrapyramidal disorders. (from martindale, the extra pharmacopoeia, 30th ed, p612)
  • Promazine

    a phenothiazine with actions similar to chlorpromazine but with less antipsychotic activity. it is primarily used in short-term treatment of disturbed behavior and as an antiemetic.
  • Thiethylperazine

    a dopamine antagonist that is particularly useful in treating the nausea and vomiting associated with anesthesia, mildly emetic cancer chemotherapy agents, radiation therapy, and toxins. this piperazine phenothiazine does not prevent vertigo or motion sickness. (from ama drug evaluations annual, 1994, p457)
  • Thioridazine

    a phenothiazine antipsychotic used in the management of phycoses, including schizophrenia.
  • Trifluoperazine

    a phenothiazine with actions similar to chlorpromazine. it is used as an antipsychotic and an antiemetic.
  • Triflupromazine

    a phenothiazine used as an antipsychotic agent and as an antiemetic.

Coding Guidelines

Underdosing refers to taking less of a medication than is prescribed by a provider or a manufacturer's instruction. Codes for underdosing should never be assigned as principal or first-listed codes. If a patient has a relapse or exacerbation of the medical condition for which the drug is prescribed because of the reduction in dose, then the medical condition itself should be coded.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified (T43). Use the following options for the aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10-CM Code Edits are applicable to this code:

  • Unacceptable principal diagnosis - There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Convert T43.3X6A to ICD-9-CM

  • ICD-9-CM Code: -
    No Map Flag -

Table of Drugs and Chemicals

The parent code T43.3X6 of the current diagnosis code is referenced in the Table of Drugs and Chemicals, this table contains a classification of drugs, industrial solvents, corrosive gases, noxious plants, pesticides, and other toxic agents.

According to ICD-10-CM coding guidelines it is advised to do not code directly from the Table of Drugs and Chemicals, instead always refer back to the Tabular List when doing the initial coding. Each substance in the table is assigned a code according to the poisoning classification and external causes of adverse effects. It is important to use as many codes as necessary to specify all reported drugs, medicinal or chemical substances. If the same diagnosis code describes the causative agent for more than one adverse reaction, poisoning, toxic effect or underdosing, utilize the code only once.

Substance Poisoning
Accidental
(unintentional)
Poisoning
Accidental
(self-harm)
Poisoning
Assault
Poisoning
Undetermined
Adverse
effect
Underdosing
AcepromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
AcetophenazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
AlimemazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ButaperazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
CarfenazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
CarphenazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ChlorpromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
CompazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
CyamemazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
DimetotiazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
DioxopromethazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
DixyrazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
FentazinT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
FluopromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
FluphenazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
IsopromethazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
LargactilT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
LevomepromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
LevopromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MellarilT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MepazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MequitazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MesoridazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MethdilazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MethopromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MethotrimeprazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MethoxypromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
MetofenazateT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
OxomemazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PecazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PerazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PericiazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PerphenazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
Phenothiazine (psychotropic) NECT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
Phenothiazine (psychotropic) NEC
  »insecticide
T43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PiperacetazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PipotiazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PlegicilT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ProchlorperazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
PromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
Promethazine (teoclate)T43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
Propylaminopheno-thiazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
SparineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
StelazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
StemetilT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
SulforidazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
Thiazinamium metilsulfateT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ThiethylperazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ThiopropazateT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ThioproperazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ThioridazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
ThorazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
TindalT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
TrifluoperazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6
TriflupromazineT43.3X1T43.3X2T43.3X3T43.3X4T43.3X5T43.3X6

Patient Education


Medication Errors

Medicines treat infectious diseases, prevent problems from chronic diseases, and ease pain. But medicines can also cause harmful reactions if not used correctly. Errors can happen in the hospital, at the health care provider's office, at the pharmacy, or at home. You can help prevent errors by:

  • Knowing your medicines. When you get a prescription, ask the name of the medicine and check to make sure that the pharmacy gave you the right medicine. Make sure that you understand how often you should take the medicine and how long you should take it.
  • Keeping a list of medicines.
    • Write down all of the medicines that you are taking, including the names of your medicines, how much you take, and when you take them. Make sure to include any over-the-counter medicines, vitamins, supplements, and herbs that you take.
    • List the medicines that you are allergic to or that have caused you problems in the past.
    • Take this list with you every time you see a health care provider.
  • Reading medicine labels and following the directions. Don't just rely on your memory - read the medication label every time. Be especially careful when giving medicines to children.
  • Asking questions. If you don't know the answers to these questions, ask your health care provider or pharmacist:
    • Why am I taking this medicine?
    • What are the common side effects?
    • What should I do if I have side effects?
    • When should I stop this medicine?
    • Can I take this medicine with the other medicines and supplements on my list?
    • Do I need to avoid certain foods or alcohol while taking this medicine?

Food and Drug Administration


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.