Drug Induced CNS Depression

Dr. Ayush PandeyMBBS,PG Diploma

December 01, 2018

March 06, 2020

Drug Induced CNS Depression
Drug Induced CNS Depression

What is drug-induced CNS depression?

Depression of the central nervous system (CNS) refers to the slowing down of the body’s neurological functions performed by the brain and the spinal cord (which constitute the CNS). CNS depression can be caused due to drugs commonly known as CNS depressants. This category of drug includes tranquilizers, sedatives and substances, which tend to slow down the activity of the brain.

What are its main signs and symptoms?

The symptoms of CNS depression include:

  • Lack of coordination
  • Slurred speech and speech difficulty
  • Difficulty in conveying thoughts
  • Drowsiness
  • Lethargy
  • Mild confusion
  • Difficulty in breathing
  • Slower heart rate (if it is a case of severe depression)
  • Inability to take a decision
  • Problems in understanding instructions or words of others
  • Lack of response when needed
  • Behavioural problems
  • Avoiding conversations

In case of severe CNS depression, the individual may slip into a state of coma. In advanced stages, CNS depression can be fatal.

What are the main causes?

Drugs are a well-known cause of CNS depression. These drugs have an impact on the neurotransmitters (chemical compounds in the brain), which in turn result in the slowing down of the brain’s activity. The most common CNS depressants that can lead to CNS depression are:

  • Barbiturates (these drugs are not very commonly used but can be prescribed by the doctor in order to control severe anxiety or treat seizure disorders).
  • Sleep medications (Non-benzodiazepine sleep medications are prescribed to individuals with sleep disorders or difficulties. They reduce anxiousness and have fewer side effects).
  • Benzodiazepines (medications composed of benzodiazepines are prescribed to treat anxiety, nervousness, extreme stress reactions, and panic attacks. They calm the brain’s functions. However, these are not very commonly used since they pose a high risk of dependence and consequent addiction).

How is it diagnosed and treated?

Most of these drugs, if prescribed, are meant for the control of extreme symptoms like anxiety and sleep problems, which are interfering with the productivity of the person. CNS depression is mostly diagnosed clinically by the description of the symptoms.

In some cases, the doctor may assess the response rate and concentration after administering a small dose of the prescribed drug. Blood tests and CT scans are also effective for diagnosing CNS depression.

Based on the severity of the symptoms, the doctors may decrease the prescribed dosage slowly or stop it completely. The treatment largely depends on the reason why one has been taking these drugs.

In addition, consumption of alcohol must be avoided, since it may induce temporary euphoria (state of happiness) but ultimately leads to slowing down of the central nervous system.


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  2. Lane RJ, Routledge PA. Drug-induced neurological disorders. Drugs. 1983 Aug;26(2):124-47. PMID: 6349966
  3. National Cancer Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; NCI Dictionary of Cancer Terms
  4. National institute of drug abuse. What are prescription CNS depressants?. National Institute of health. [internet].
  5. U.S food and drug administration. Drug Safety Communications. US. [internet].

Medicines for Drug Induced CNS Depression

Medicines listed below are available for Drug Induced CNS Depression. Please note that you should not take any medicines without doctor consultation. Taking any medicine without doctor's consultation can cause serious problems.

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