2024 ICD-10-CM Diagnosis Code T43.1X6A

Underdosing of monoamine-oxidase-inhibitor antidepressants, initial encounter

ICD-10-CM Code:
T43.1X6A
ICD-10 Code for:
Underdosing of MAO inhib antidepressants, 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)

T43.1X6A is a billable diagnosis code used to specify a medical diagnosis of underdosing of monoamine-oxidase-inhibitor antidepressants, 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.

T43.1X6A 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 monoamine-oxidase-inhibitor antidepressants. 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

  • Iproniazid

    an irreversible inhibitor of monoamine oxidase types a and b that is used as an antidepressive agent. it has also been used as an antitubercular agent, but its use is limited by its toxicity.
  • Carboxylesterase

    carboxylesterase is a serine-dependent esterase with wide substrate specificity. the enzyme is involved in the detoxification of xenobiotics and the activation of ester and of amide prodrugs.
  • Isocarboxazid

    an mao inhibitor that is effective in the treatment of major depression, dysthymic disorder, and atypical depression. it also is useful in the treatment of panic disorder and the phobic disorders. (from ama, drug evaluations annual, 1994, p311)
  • Moclobemide

    a reversible inhibitor of monoamine oxidase type a; (rima); (see monoamine oxidase inhibitors) that has antidepressive properties.
  • Nialamide

    an mao inhibitor that is used as an antidepressive agent.
  • Phenelzine

    one of the monoamine oxidase inhibitors used to treat depression; phobic disorders; and panic.
  • Tranylcypromine

    a propylamine formed from the cyclization of the side chain of amphetamine. this monoamine oxidase inhibitor is effective in the treatment of major depression, dysthymic disorder, and atypical depression. it also is useful in panic and phobic disorders. (from ama drug evaluations annual, 1994, p311)

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 T43.1X6A to ICD-9-CM

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

Table of Drugs and Chemicals

The parent code T43.1X6 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
AmiflamineT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
ClorgilineT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
IproclozideT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
IproniazidT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
IsocarboxazidT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
MAO inhibitorsT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
MarplanT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
MarsilidT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
MebanazineT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
MoclobemideT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
Monoamine oxidase inhibitor NECT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
Monoamine oxidase inhibitor NEC
  »hydrazine
T43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
NardilT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
NialamideT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
ParnateT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
PhenelzineT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
PheniprazineT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
SafrazineT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6
TranylcypromineT43.1X1T43.1X2T43.1X3T43.1X4T43.1X5T43.1X6

Patient Education


Antidepressants

What are antidepressants?

Antidepressants are prescription medicines to treat depression. Depression is more than feeling a little sad or "blue" for a few days. It's a very common, serious medical illness that affects your mood and general mental health It can make you feel tired, hopeless, worried, or fearful. It can change your thinking, sleeping, and eating. Depression may make some people think about ending their lives.

But antidepressants can help many people who have depression. Researchers think antidepressants may help improve the way your brain uses certain chemicals that control mood or stress.

Are antidepressants used for other conditions?

A health care provider may prescribe antidepressants for anxiety, chronic pain, or insomnia. Sometimes providers also prescribe antidepressants for other conditions.

What are the different types of antidepressants?

There are many types of antidepressants. Each one works differently. Providers usually prescribe newer antidepressants first because they don't cause as many side effects as older types. They also seem to help more kinds of depression and anxiety problems.

Most of the newer antidepressants belong to one of these three groups:

  • Selective serotonin reuptake inhibitors (SSRIs)
  • Serotonin and norepinephrine reuptake inhibitors (SNRIs)
  • Atypical antidepressants, which are newer antidepressants that don't fit into the other groups

If these antidepressants don't help, your provider might suggest one of the older antidepressants. The older types include tricyclic antidepressants (TCAs), tetracyclics, and monoamine oxidase inhibitors (MAOIs). Even though these antidepressants may cause more serious side effects, the benefits may outweigh the risks for some people.

Which type of antidepressant is right for me?

Our bodies and brains all work differently. That means one antidepressant won't work for everyone. You may need to try two or more medicines before you find one that works for you.

Your provider will work with you to choose the best option to try first. You'll consider questions such as:

  • Which symptoms bother you most? Some antidepressants may do a better job helping specific symptoms, such as trouble sleeping.
  • What other medicines and supplements do you take? Some antidepressants can cause problems if you take them with certain medicines and herbs.
  • Did a certain antidepressant work well for a close relative? An antidepressant that helped a parent, brother, or sister could be a good choice for you, too.
  • Do you have other health conditions? Certain antidepressants can make some other conditions better or worse. Any other conditions that you have will be part of choosing your depression treatment.
  • Are you pregnant, planning for pregnancy, or breastfeeding? If so, your provider will help you find a way to treat your depression that's safe for you and your baby.

How long do antidepressants take to work?

Antidepressants usually take 4 to 8 weeks to work, so you'll need to be patient. You may notice that some problems, such as sleeping and eating, get better before your mood improves. That's a good sign. You may just need to give the medicine a little more time to do its job.

Sometimes an antidepressant helps at first, but symptoms return while you're still taking it. But there's usually another one you can try. To get more relief from depression, your provider may suggest combining two antidepressants, using another kind of medicine with an antidepressant, or adding talk therapy or other approaches to improve your mental health.

How long will I need to take an antidepressant?

When an antidepressant starts to work, you and your provider can decide how long you need to stay on it. The typical length of treatment is 6 to 12 months, but some people may stay on antidepressants for much longer.

What are the side effects of antidepressants?

Not everyone has side effects from antidepressants. But if you do have them, they're usually mild and may get better over time as your body gets used to the new medicine.

The most common side effects from antidepressants include:

  • Nausea and vomiting
  • Weight gain
  • Diarrhea
  • Sleepiness
  • Sexual problems, such as a lack of desire or ability to have sex

When thinking about side effects, it's important to remember that there are also risks from not treating depression. Your provider can help you think through the pros and cons of all your options.

If you have any side effects from antidepressants, your provider may suggest ways to manage them while you wait to see if the antidepressant will work. If the side effects bother you too much, you may need to change antidepressants. But you should never change your dose or stop taking an antidepressant on your own.

If you have serious problems or notice any changes that worry you, such as new or worsening symptoms, unusual changes in your mood, or you start acting differently, call your provider right away.

In some cases, children, teenagers, and young adults under 25 may be more likely to think about hurting or killing themselves when starting antidepressants or when the dose is changed. Get medical help right away if this happens.

What can I do to take antidepressants safely?

Antidepressants are generally safe when you use them correctly:

  • Tell your provider about everything you take. That includes medicines, herbs, supplements, and over-the-counter medicines you take, such as pain relievers and decongestants. Be honest about recreational drugs and alcohol, too.
  • Try to get all your medicines from the same pharmacy. That way the pharmacist can warn you and your provider if you take medicines that may cause problems when used together.
  • Follow all instructions about how to take your medicine.
  • Talk with your provider if side effects bother you.
  • Never stop taking antidepressants without your provider's help. Stopping too fast may make depression come back. You could even make your condition worse. To stop antidepressants safely, you need to give your body time to get used to being without the medicine. Your provider can tell you the safest way to go off an antidepressant.

NIH: National Institute of Mental Health


[Learn More in MedlinePlus]

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.