2024 ICD-10-CM Diagnosis Code T40.991

Specific Coding Applicable to Poisoning by oth psychodyslept, accidental (unintentional)

Non-specific codes like T40.991 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 poisoning by oth psychodyslept, accidental (unintentional):

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

• Accidental mescaline overdose
• Accidental poisoning by hallucinogens
• Accidental poisoning by hallucinogens
• Accidental poisoning by hallucinogens
• Accidental poisoning by hallucinogens
• Accidental poisoning by hallucinogens
• Accidental poisoning by mescaline
• Accidental poisoning by psilocin
• Accidental poisoning by psilocybin
• Accidental psilocybin overdose
• Mescaline overdose
• Phencyclidine poisoning
• Poisoning by mescaline
• Poisoning by psilocin
• Poisoning by psilocybin
• Psilocybin overdose

Clinical Information

• Mescaline

  hallucinogenic alkaloid isolated from the flowering heads (peyote) of lophophora (formerly anhalonium) williamsii, a mexican cactus used in indian religious rites and as an experimental psychotomimetic. among its cellular effects are agonist actions at some types of serotonin receptors. it has no accepted therapeutic uses although it is legal for religious use by members of the native american church.

• Phencyclidine

  a hallucinogen formerly used as a veterinary anesthetic, and briefly as a general anesthetic for humans. phencyclidine is similar to ketamine in structure and in many of its effects. like ketamine, it can produce a dissociative state. it exerts its pharmacological action through inhibition of nmda receptors (receptors, n-methyl-d-aspartate). as a drug of abuse, it is known as pcp and angel dust.

• Phencyclidine Abuse

  the misuse of phencyclidine with associated psychological symptoms and impairment in social or occupational functioning.

• Receptors, Phencyclidine

  specific sites or molecular structures on cell membranes or in cells with which phencyclidine reacts or to which it binds to elicit the specific response of the cell to phencyclidine. studies have demonstrated the presence of multiple receptor sites for pcp. these are the pcp/sigma site, which binds both pcp and psychotomimetic opiates but not certain antipsychotics, and the pcp site, which selectively binds pcp analogs.

• Psilocybin

  the major of two hallucinogenic components of teonanacatl, the sacred mushroom of mexico, the other component being psilocin. (from merck index, 11th ed)

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 narcotics and psychodysleptics [hallucinogens] (T40). 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.

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.