2024 ICD-10-CM Diagnosis Code T43.506

Specific Coding Applicable to Underdosing of unspecified antipsychotics and neuroleptics

Non-specific codes like T43.506 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for underdosing of unspecified antipsychotics and neuroleptics:

Clinical Information

• Tardive Dyskinesia

  drug-related movement disorder characterized by uncontrollable movements in certain muscles. it is associated with a long-term exposure to certain neuroleptic medications (e.g., metoclopramide).

• Neuroleptic Malignant Syndrome

  a potentially fatal syndrome associated primarily with the use of neuroleptic agents (see antipsychotic agents) which are in turn associated with dopaminergic receptor blockade (see receptors, dopamine) in the basal ganglia and hypothalamus, and sympathetic dysregulation. clinical features include diffuse muscle rigidity; tremor; high fever; diaphoresis; labile blood pressure; cognitive dysfunction; and autonomic disturbances. serum cpk level elevation and a leukocytosis may also be present. (from adams et al., principles of neurology, 6th ed, p1199; psychiatr serv 1998 sep;49(9):1163-72)

• Metoclopramide

  a dopamine d2 antagonist that is used as an antiemetic.

• Akathisia

  an uncomfortable feeling of inner restlessness and inability to stay still. it can be a side effect of psychotropic medications.

• Akathisia, CTCAE|Akathisia|Akathisia

  a disorder characterized by an uncomfortable feeling of inner restlessness and inability to stay still; this is a side effect of some psychotropic drugs.

• Barnes Akathisia Rating Scale Clinical Classification|BARS|BARS|BARS01

  a standardized rating scale developed by thomas r. e. barnes in 1989 to diagnose akathisia associated with use of antipsychotic agents. this instrument contains objective and subjective sections, as well as a global clinical assessment of akathisia. the first two sections contain a total of 3 items which are rated on a scale of 0 to 3 with 0 being none or normal and 3 being severe. the third section is rated on a 0 to 5 scale with 0 being none and 5 being severe.

• CDISC Clinical Classification BARS Test Code Terminology|BARS01TC|Barnes Akathisia Rating Scale Clinical Classification Test Code|QS-BARS TESTCD

  test codes of clinical classification questions associated with the barnes akathisia rating scale (bars) for the clinical data interchange standards consortium (cdisc) standard data tabulation model (sdtm).

• CDISC Clinical Classification BARS Test Name Terminology|BARS01TN|Barnes Akathisia Rating Scale Clinical Classification Test Name|QS-BARS TEST

  test names of clinical classification questions associated with the barnes akathisia rating scale (bars) for the clinical data interchange standards consortium (cdisc) standard data tabulation model (sdtm).

• Drug-Induced Akathisia|Drug induced akathisia

  evidence of drug-induced akathisia.

• ESRS-A - Akathisia: Objective|ESRSA1-Akathisia: Objective|ESRSA1-Akathisia: Objective|ESRSA124

  extrapyramidal symptom rating scale-abbreviated (esrs-a) akathisia: objective.

• ESRS-A - Akathisia: Subjective|ESRSA1-Akathisia: Subjective|ESRSA1-Akathisia: Subjective|ESRSA123

  extrapyramidal symptom rating scale-abbreviated (esrs-a) akathisia: subjective.

• ESRS-A - CGI-S Akathisia|ESRSA1-CGI-S Akathisia|ESRSA1-CGI-S Akathisia|ESRSA128

  extrapyramidal symptom rating scale-abbreviated (esrs-a) clinical global impression (cgi-s): akathisia.

• Grade 1 Akathisia, CTCAE|Grade 1 Akathisia

  mild restlessness or increased motor activity

• Grade 2 Akathisia, CTCAE|Grade 2 Akathisia

  moderate restlessness or increased motor activity; limiting instrumental adl

• Grade 3 Akathisia, CTCAE|Grade 3 Akathisia

  severe restlessness or increased motor activity; limiting self care adl

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

Table of Drugs and Chemicals

The 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.

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

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.