10. Poisoning: A Complete Guide for Pharmacy Students

POISONING AND POISON INFORMATION CENTRES

Welcome, future pharmacists and healthcare professionals!

As a pharmacy educator with years of experience teaching hospital and clinical pharmacy, I have always emphasized that poisoning is a medical emergency that requires immediate recognition and appropriate management. Poisoning refers to the harmful effects caused by toxic substances entering the body through ingestion, inhalation, or absorption. The effect depends on the dose and exposure time. Understanding poisoning and its management is essential for healthcare professionals to save lives and prevent complications.

In this comprehensive guide, I will take you through the various aspects of poisoning, including types, symptoms, treatment, antidotes, and the role of Poison Information Centres. We will also explore Drug Information Centres and their resources. By the end of this article, you will have a thorough understanding of how to manage poisoning cases and utilize poison information services. Let us begin.

WHAT IS POISONING?

Poisoning is a condition in which a person is exposed to a substance that causes harmful effects on the body. These substances, known as poisons or toxins, can enter the body through various routes including ingestion (swallowing), inhalation (breathing in), injection (through skin or veins), or absorption (through skin or mucous membranes). The severity of poisoning depends on the type and amount of poison, the route of exposure, and the time elapsed since exposure.

Poisoning can be accidental, intentional (suicidal or homicidal), or occupational. It is a significant public health concern worldwide, with thousands of cases reported annually. Prompt recognition and appropriate management are crucial to prevent morbidity and mortality.

TYPES OF POISONING

1. Ingested Poisoning

Ingested poisoning occurs when toxic substances are swallowed. Common causes include:

• Household chemicals: Cleaning agents, detergents, pesticides.
• Drug overdose: Accidental or intentional consumption of excessive medication.
• Spoiled food: Food contaminated with bacteria or toxins.

Symptoms: Nausea, vomiting, diarrhea, abdominal pain, dizziness, and in severe cases, difficulty breathing, seizures, or coma.

Treatment: Activated charcoal to absorb the poison, specific antidotes if available, and supportive care including IV fluids and monitoring of vital signs.

2. Inhaled Poisoning

Inhaled poisoning occurs when toxic gases, fumes, or vapors are breathed in. Common sources include carbon monoxide, smoke, industrial chemicals, and household gases.

Symptoms: Headache, weakness, confusion, dizziness, difficulty breathing, and in severe cases, loss of consciousness.

Treatment: Immediate removal from the source of exposure, oxygen therapy, and hyperbaric oxygen therapy for conditions like carbon monoxide poisoning.

3. Food Poisoning

Food poisoning is caused by the consumption of contaminated food containing bacteria, viruses, parasites, or their toxins.

Symptoms: Vomiting, diarrhea, fever, abdominal cramps, and dehydration.

Treatment: Oral rehydration therapy (ORS) to replace lost fluids, antibiotics if bacterial infection is confirmed, and supportive care.

4. Injected Poisoning

Injected poisoning occurs when toxic substances are introduced into the body through bites, stings, or injections. Common sources include insect stings, snake bites, and drug injections.

Treatment: Antihistamines for allergic reactions, specific antivenoms for snake bites, and supportive care.

5. Insecticide Poisoning

Insecticide poisoning occurs due to exposure to pesticides such as organophosphates, carbamates, and DDT.

Symptoms: Convulsions, difficulty breathing, excessive salivation, muscle twitching, and in severe cases, respiratory failure.

Treatment: Atropine to counteract muscarinic effects, pralidoxime to reactivate acetylcholinesterase, and supportive care.

6. Heavy Metal Poisoning

Heavy metal poisoning occurs due to exposure to toxic metals such as lead, mercury, arsenic, and cadmium. Sources include contaminated water, industrial exposure, and certain traditional medicines.

Symptoms: Neurological effects (memory loss, confusion), organ damage (kidney, liver), gastrointestinal symptoms, and in severe cases, coma.

Treatment: Chelation therapy using agents like EDTA (for lead), dimercaprol (for arsenic and mercury), and penicillamine (for copper).

7. Narcotic Poisoning

Narcotic poisoning occurs due to overdose of opioid drugs such as morphine, heroin, codeine, and synthetic opioids like fentanyl.

Symptoms: CNS depression, respiratory depression, pinpoint pupils, coma, and death if untreated.

Treatment: Naloxone (opioid antagonist) to reverse respiratory depression, and supportive care including ventilation and monitoring.

GENERAL TREATMENT OF POISONING

The management of poisoning follows a systematic approach:

1. Remove unabsorbed poison: Depending on the route of exposure, this may involve gastric lavage (stomach washing), skin decontamination (washing with soap and water), or removing the patient to fresh air (for inhaled poisons).
2. Remove absorbed poison: Once the poison has entered the bloodstream, methods such as diuretics to increase urine output, dialysis to filter the blood, or haemoperfusion may be used.
3. Use antidotes: Specific antidotes are available for certain poisons. These neutralize the toxic effects or counteract the symptoms.
4. Provide supportive care: Maintain vital functions such as breathing, circulation, and hydration. Monitor the patient for complications.

COMMON ANTIDOTES

Antidote	Poisoning Type
Acetylcysteine	Paracetamol poisoning
Atropine	Organophosphorus poisoning
Naloxone	Opioid poisoning
EDTA	Lead poisoning
Dimercaprol	Arsenic, mercury poisoning
Penicillamine	Copper, lead poisoning

Universal Antidote

The universal antidote is a mixture used in general poisoning cases when the specific poison is unknown. It contains:

• Activated charcoal: Adsorbs many poisons and prevents their absorption.
• Tannic acid: Precipitates alkaloids and heavy metals.
• Magnesium oxide: Neutralizes acids.

However, its use is now limited as activated charcoal alone is often more effective and has fewer side effects.

DRUG INFORMATION CENTRE (DIC)

A Drug Information Centre (DIC) is a specialized service that provides drug-related information to healthcare professionals and the public. Its functions include:

• Provides drug-related information: Offers evidence-based information on drug indications, dosing, interactions, side effects, and safety.
• Promotes rational drug use: Helps healthcare providers make informed prescribing decisions.
• Supports clinical decisions: Assists in the selection of appropriate drug therapy for individual patients.

Resources of DIC

• Primary sources: Original research articles published in peer-reviewed journals such as The Lancet, BMJ, and other scientific publications.
• Secondary sources: Databases such as PubMed, Embase, and Micromedex that provide access to primary literature.
• Tertiary sources: Textbooks, drug compendia, and reference books that summarize and synthesise drug information.

POISON INFORMATION CENTRE (PIC)

A Poison Information Centre (PIC) is a specialized facility that provides guidance and support for poisoning cases. It plays a crucial role in reducing mortality and improving treatment outcomes.

Functions of PIC

• Provide poison information: Offer immediate information on the toxicity of substances, symptoms, and management of poisoning cases.
• Assist in treatment: Guide healthcare professionals on appropriate treatment protocols, including the use of antidotes.
• Conduct toxicology analysis: Perform laboratory analysis to identify poisons and assess the severity of poisoning.
• Public awareness programs: Educate the public on poisoning prevention, first aid, and the importance of seeking medical help.

A TEACHER’S PRACTICAL INSIGHTS

Over my years of teaching, I have developed a few key insights about poisoning and poison information centres that I always share with my students:

• Act quickly: In poisoning cases, time is critical. Early recognition and prompt treatment can save lives.
• Know your antidotes: Familiarize yourself with common antidotes and their indications. This knowledge is essential for emergency management.
• Use poison information centres: PICs are valuable resources. Do not hesitate to contact them for guidance in poisoning cases.
• Focus on prevention: Many poisoning cases are preventable. Educate patients about safe storage of medicines and chemicals.

FREQUENTLY ASKED QUESTIONS (FAQs)

1. What is poisoning?

Poisoning is the harmful effect caused by toxic substances entering the body through ingestion, inhalation, or absorption.

2. What are the common types of poisoning?

Common types include ingested, inhaled, food, injected, insecticide, heavy metal, and narcotic poisoning.

3. What is the treatment for insecticide poisoning?

Treatment includes atropine, pralidoxime, and supportive care.

4. What is the role of a Poison Information Centre?

A PIC provides poison information, assists in treatment, conducts toxicology analysis, and runs public awareness programs.

5. What is the universal antidote?

The universal antidote contains activated charcoal, tannic acid, and magnesium oxide. However, activated charcoal alone is now more commonly used.

6. What is chelation therapy?

Chelation therapy uses agents like EDTA or dimercaprol to bind and remove heavy metals from the body in cases of heavy metal poisoning.

7. Why are Poison Information Centres important?

PICs are important because they provide expert guidance in poisoning cases, reduce mortality, and educate the public on prevention.

SUMMARY

Poisoning is a medical emergency caused by the entry of toxic substances into the body. It can occur through ingestion, inhalation, absorption, or injection. The severity depends on the type and amount of poison, route of exposure, and time elapsed.

Types of poisoning include ingested, inhaled, food, injected, insecticide, heavy metal, and narcotic poisoning. General treatment involves removing unabsorbed poison, removing absorbed poison, using antidotes, and providing supportive care.

Drug Information Centres (DIC) provide drug-related information and promote rational drug use. Poison Information Centres (PIC) provide guidance for poisoning cases, assist in treatment, and conduct public awareness programs. Understanding poisoning and the role of information centres is essential for healthcare professionals to save lives and prevent complications.

As I always tell my students: “Poisoning is a race against time. Knowledge of antidotes and poison information centres can mean the difference between life and death.”

REFERENCES & FURTHER READING

• Government of India. (1948). The Pharmacy Act, 1948. Ministry of Health and Family Welfare.
• World Health Organization (WHO). (2023). Poisoning Prevention and Management Guidelines. Retrieved from WHO Official Website.
• International Pharmaceutical Federation (FIP). (2023). Poison Information Centre Guidelines. Retrieved from FIP Official Website.
• American Association of Poison Control Centers (AAPCC). (2023). Poison Information Resources. Retrieved from AAPCC Official Website.
• National Poisons Information Service (NPIS). (2023). Clinical Toxicology Guidelines. Retrieved from NPIS Official Website.

Disclaimer: This article is for educational purposes only and does not constitute medical or legal advice. Always consult qualified healthcare professionals and regulatory authorities for professional and legal matters.