Drug overdose

Drug overdose
Classification and external resources

Activated charcoal with sorbitol. A commonly used agent for decontamination of the gastrointestinal tract in overdoses.
ICD-10 T36-T50
ICD-9 960-979
MeSH D015537

The term drug overdose (or simply overdose or OD) describes the ingestion or application of a drug or other substance in quantities that are excessive.[1] An overdose is widely considered harmful and dangerous as it can result in death.

Contents

Classification

The word "overdose" implies that there is a common safe dosage and usage for the drug; therefore, the term is commonly only applied to drugs, not poison, though even certain poisons are harmless at a low enough dosage. Drug overdoses are sometimes caused intentionally to commit suicide or as self-harm, but many drug overdoses are accidental and are usually the result of either irresponsible behavior or the misreading of product labels. Drug overdose often happens as a result of the use of multiple drugs with counter indications simultaneously (for instance, heroin/certain prescription pain medications and cocaine/amphetamines/alcohol.) Usage of illicit drugs that are of unexpected purity, in large quantities, or after a period of abstinence can also induce overdose. Cocaine users that inject intravenously can overdose accidentally as the margin between an optimal flash and an overdose is small.[2]

Accidental overdoses can eventuate out of a number of different causes including overprescription, failing to recognise a drug's active ingredient, or unwitting ingestion by children[3] A common unintentional overdose in young children involves multi-vitamins containing iron. Iron is a component of the hemoglobin molecule in blood, used to transport oxygen to living cells. When taken in small amounts, iron allows the body to replenish hemoglobin, but in large amounts it causes severe pH imbalances in the body. If this overdose is not treated with chelation therapy, it can lead to death or permanent coma.

Signs and symptoms

Signs and symptoms of an overdose varies depending on the drug or toxin exposure. The symptoms can often be divided into differing toxidromes. This can help one determine what class of drug or toxin is causing the difficulties.

A summary of the toxidromes:[4]

toxidrome BP HR RR Temp Pupils bowel sounds diaphoresis
anticholinergic ~ up ~ up up down down
cholinergic ~ ~ unchanged unchanged unchanged up up
opioid down down down down down down down
sympathomimetic up up up up up up up
sedative-hypnotic down down down down ~ down down

Causes

The drugs or toxins which are most frequently involved in overdose and death (grouped by ICD-10):

  • Among sedative-hypnotics (F13)
    • Among Barbiturate overdose (T42.3)
      • Amobarbital
      • Pentobarbital
      • Secobarbital
    • Among Benzodiazepine overdose (T42.4)
    • Uncategorized sedative-hypnotics (T42.6)
  • Among Poly drug use (F19)
    • Drug "cocktails" (Speedballs)
  • Medications/pharmaceuticals
    • Aspirin poisoning (T39.0)
    • Paracetamol toxicity (T39.1)
    • Tricyclic antidepressant overdose (T43.0)
  • Pesticide poisoning (T60)
    • Organophosphate poisoning
    • DDT

Diagnosis

Determination of the substance which was taken is often easy as usually the person knows what they took. However, if they will not or cannot due to an altered level of consciousness provide this information a search of the home or questioning of friends and family may be helpful.

Examination for toxidromes, drug testing, or laboratory test may be helpful. Naloxone the antidote for narcotics may be administered and if they improve it indicates this is probably part of the overdose.

Negative drug-drug interactions have sometimes been misdiagnosed as an acute drug overdose, occasionally leading to the assumption of suicide. [5]

Prevention

The distribution of naloxone to injection drug users decreases the risk of death from overdose.[6]

Avoid the mixing depressant drugs like alcohol, barbiturates, benzodiazepines, and opiates. [7]

Management

Stabilization of the ABCs are the initial treatment of an overdose. This involves establishing a stable airway, breathing rate and circulatory system as an essential first step. Ventilation is considered when there is a low respiratory rate or when blood gases show the person to be hypoxic. The next necessary step is to treat for shock. Investigations should be carried out in labs to help identify the drug(s) at hand such as glucose, urea and electrolytes, paracetamol levels and salicylate levels. Monitoring of the patient should continue before and throughout the treatment process, with particular attention to temperature, pulse, respiratory rate, blood pressure, urine output, electrocardiography (ECG) and O2 saturation.[8]

Antidotes

Specific antidotes are available for certain causative agents. The overdose agent is usually determined either via history or laboratory toxicology.

Poison control centers and Medical toxicologists are available in many areas to provide guidance in overdoses to both physicians and the general public.

Epidemiology

The National Center for Health Statistics report that 19,250 people died of accidental poisoning in the U.S. in the year 2004 (8 deaths per 100,000 population).[9]

In 2008 testimony before a Senate subcommittee, Medical Epidemiologist Dr. Leonard J. Paulozzi[10] of the Centers for Disease Control and Prevention stated that in 2005 (the most recent year for which data was available) more than 22,000 American lives were lost due to overdoses, and the number is growing rapidly. Dr. Paulozzi also testified that all available evidence suggests that unintentional overdose deaths are related to the increasing use of prescription drugs, especially opioid painkillers. [11]

See also

References

  1. overdose at Dorland's Medical Dictionary
  2. Study on fatal overdose in New-York City 1990-2000, visited May 11, 2008
  3. "What to do with leftover medicines". Medicines Talk, Winter 2005. Available at http://www.nps.org.au/consumers/publications/medicines_talk/mt14/what_to_do_with_left-over_medicines2
  4. Goldfrank, Lewis R. (1998). Goldfrank's toxicologic emergencies. Norwalk, CT: Appleton & Lange. ISBN 0-8385-3148-2. 
  5. Column - Fatal Drug-Drug Interaction As a Differential Consideration in Apparent Suicides
  6. Piper TM, Stancliff S, Rudenstine S, et al. (2008). "Evaluation of a naloxone distribution and administration program in New York City". Subst Use Misuse 43 (7): 858–70. doi:10.1080/10826080701801261. PMID 18570021. 
  7. Mixing drugs
  8. Longmore, Murray; Ian Wilkinson, Tom Turmezei, Chee Kay Cheung (2007). Oxford Handbook of Clinical Medicine. United Kingdom: Oxford. ISBN 0-19-856837-1. 
  9. National Center for Health Statistics
  10. Centers for Disease Control and Prevention
  11. Centers for Disease Control and Prevention

Further reading

  • Nelson, Lewis H.; Flomenbaum, Neal; Goldfrank, Lewis R.; Hoffman, Robert Louis; Howland, Mary Deems; Neal A. Lewin (2006). Goldfrank's toxicologic emergencies. New York: McGraw-Hill, Medical Pub. Division. ISBN 0-07-143763-0. 

External links