2024 ICD-10-CM Diagnosis Code T43.20

Poisoning by, adverse effect of and underdosing of unspecified antidepressants

ICD-10-CM Code:
T43.20
ICD-10 Code for:
Unsp antidepressants
Is Billable?
Not Valid for Submission
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)

T43.20 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of poisoning by, adverse effect of and underdosing of unspecified antidepressants. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Unspecified diagnosis codes like T43.20 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Specific Coding Applicable to Unsp antidepressants

Non-specific codes like T43.20 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 unsp antidepressants:

  • T43.201 for Poisoning by unspecified antidepressants, accidental (unintentional) - NON-BILLABLE CODE

  • Use T43.201A for initial encounter - BILLABLE CODE

  • Use T43.201D for subsequent encounter - BILLABLE CODE

  • Use T43.201S for sequela - BILLABLE CODE

  • T43.202 for Poisoning by unspecified antidepressants, intentional self-harm - NON-BILLABLE CODE

  • Use T43.202A for initial encounter - BILLABLE CODE

  • Use T43.202D for subsequent encounter - BILLABLE CODE

  • Use T43.202S for sequela - BILLABLE CODE

  • T43.203 for Poisoning by unspecified antidepressants, assault - NON-BILLABLE CODE

  • Use T43.203A for initial encounter - BILLABLE CODE

  • Use T43.203D for subsequent encounter - BILLABLE CODE

  • Use T43.203S for sequela - BILLABLE CODE

  • T43.204 for Poisoning by unspecified antidepressants, undetermined - NON-BILLABLE CODE

  • Use T43.204A for initial encounter - BILLABLE CODE

  • Use T43.204D for subsequent encounter - BILLABLE CODE

  • Use T43.204S for sequela - BILLABLE CODE

  • T43.205 for Adverse effect of unspecified antidepressants - NON-BILLABLE CODE

  • Use T43.205A for initial encounter - BILLABLE CODE

  • Use T43.205D for subsequent encounter - BILLABLE CODE

  • Use T43.205S for sequela - BILLABLE CODE

  • T43.206 for Underdosing of unspecified antidepressants - NON-BILLABLE CODE

  • Use T43.206A for initial encounter - BILLABLE CODE

  • Use T43.206D for subsequent encounter - BILLABLE CODE

  • Use T43.206S for sequela - BILLABLE CODE

Coding Guidelines

When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined. If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.

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

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]

Drug Reactions

Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.

What is a drug interaction?

A drug interaction is a change in the way a drug acts in the body when taken with certain other drugs, foods, or supplements or when taken while you have certain medical conditions. Examples include:

  • Two drugs, such as aspirin and blood thinners
  • Drugs and food, such as statins and grapefruit
  • Drugs and supplements, such as gingko and blood thinners
  • Drugs and medical conditions, such as aspirin and peptic ulcers

Interactions could cause a drug to be more or less effective, cause side effects, or change the way one or both drugs work.

What are side effects?

Side effects are unwanted, usually unpleasant, effects caused by medicines. Most are mild, such as a stomachache, dry mouth, or drowsiness, and go away after you stop taking the medicine. Others can be more serious. Sometimes a drug can interact with a disease that you have and cause a side effect. For example, if you have a heart condition, certain decongestants can cause you to have a rapid heartbeat.

What are drug allergies?

Drug allergies are another type of reaction. They can range from mild to life-threatening. Skin reactions, such as hives and rashes, are the most common type. Anaphylaxis, a serious allergic reaction, is less common.

How can I stay safe when taking medicines?

When you start a new prescription or over-the-counter medicine, make sure you understand how to take it correctly. Know which other medicines, foods, and supplements you need to avoid. Always talk to your health care provider or pharmacist if you have questions about your medicines.


[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.