EHS 202 Week 6 Drugs of Abuse Lecture 2022-2023 PDF

EHS 202 Pharmacology for EMS Week 6 Poisoning, Overdoses & Drug Abuse Introduction Poisonings and overdose account for a significant percentage of EMS responses As a prehospital provider you may see many types of overdose Poisoning and overdose situations may be associated wi...

EHS 202 Pharmacology for EMS Week 6 Poisoning, Overdoses & Drug Abuse Introduction Poisonings and overdose account for a significant percentage of EMS responses As a prehospital provider you may see many types of overdose Poisoning and overdose situations may be associated with trauma, suicide attempts, psychiatric illness, or other types of medical emergencies 2  Objectives of this lecture Discuss ‘overdose’ in relation to paramedic practice. Describe the assessment and management of common toxins encountered in the overdose setting. Describe the physiological affects of common overdose toxins. Review clinical guidelines for the management of patient’s presenting with signs and symptoms suggestive of overdose.  Overdose & Poisoning Toxicological emergencies are a common cause of calls to the ambulance service and can present unique challenges. The incidence of overdose and poisoning is difficult to quantify as not all cases are reported, especially those relating to intentional or illegal incidents Management of toxicological emergencies requires the paramedic to think critically to identify issues of safety, the source of the substance involved, consider differential diagnosis and formulate a treatment plan.  Overdose & Poisoning Toxicological emergencies may be found in cases where the primary reason for the call is not drug related. For this reason the paramedic must have a solid understanding of the variety of substances and medications encountered in the pre-hospital setting as well as the pharmacokinetics and pharmacodynamics. Exposure may occur by ingestion, inhalation, topical, absorption, injection, inoculation or radiation. Overdose and poisoning can occur through accidental or intentional exposure. Accidental overdose is common amongst children under the age of six years. The most common exposure is ingestion as a result of inadequate supervision. Intentional overdose is common in acts of deliberate self-harm associated with suicide attempts, psychiatric illness or other medical emergencies. A third and much less common presentation are those patients exposed to toxins through biological and chemical warfare / terrorism 5  Overdose & Poisoning Common terms: Toxicology – the study of toxic or poisonous substances Poison – A substance whose actions can result in damage to structures or reduce the normal function when introduced to the body. Even small amounts of a poison can result in serious outcomes including death. A poison is always a poison. Drug – A drug is a substance that has some therapeutic effects such as reducing pain, reducing temperature or fighting infection. When administered through the correct route and in the correct doses. Toxin – Is a naturally occurring poison or harmful substance produced by a living organism such as bacteria, plant or animal. Overdose – Occurs when a drug is taken in excess, this can be either a legal or illegal substance. A drug if taken in excess may poison a person. 6  Overdose & Poisoning Severity and outcome of overdose and poisoning will depend on a number of factors including the age and weight of the patient, the toxicity of the drug, toxin or poison, the quantity, route of exposure and co-morbidities or physical injury. The toxic effects following exposure will depend on the specific substance. Paramedics encounter many common types of overdose including over the counter or prescribed medications, alcohol (ethanol) and opiates. For this reason paramedics must be familiar with the variety of symptoms and presentations and their management strategies. 7  Case Study You have been dispatched to reports of a collapsed male, unconscious from an unknown cause. The call was made by the police who are on scene with the patient. On examination you find a male, approximately 30-years-old, lying prone and responding only to pain. His respiratory rate is 10 with shallow breathing and reduced tidal volume, his blood pressure is 110/72 and his heart rate is 120 beats per minute. He appears intoxicated and has needle marks and scars on both arms. Next to him there is a bag of drug paraphernalia, needles and an unknown brown substance which the police believe to be heroin. 8  Scene Safety Personal safety and the safety of those around you is of paramount importance at any emergency call regardless of the nature of the call. Paramedics have a duty of care to provide care for their patients and provide a safe environment for those around them. This represents a moral, ethical and professional challenge. In circumstances such as overdose, paramedics must carefully balance issues relating to safety with the clinical need and interventions for the patient. 9 Your approach to every scene should include an assessment of the following:  D – Danger  R – Response  A – Airway  B – Breathing  C – Circulation Your first priority should be to consider specific risk factors associated to the call details you have received. They should be considered sequentially and not in a specific order. Incases where overdose is suspected, the paramedic must consider the additional risk from violence and sharps injuries from intravenous drug equipment and expose to blood borne infections including hepatitis and HIV. 10 Common Drugs of Abuse Drugs that are commonly abused are: Narcotic (Opiate & opioid) Sedative, hypnotic / central nervous system depressants Sympathomimetic / central nervous system stimulants. Anticholinergic Polypharmacy or multiple drug use is common in overdose situations. 11 Common Drugs of Abuse, Overdose - & Toxins Prescription Illicit Opiate based medications including: Cocaine (CNS stimulant) Morphine, Codeine, Oxycodone, MDMA / Ecstacy (CNS stimulant) Fentanyl, Tramadol Methamphetamine (CNS stimulant) Antidepressants including: Amphetamines (CNS stimulant) Amitriptyline, Seroxat, Citalopram, GHB / Gamma Hydroxybutyrate Sertraline (CNS stimulant) Non-benzodiazepines including; Cannabis (Hallucinogen) Zolpidem, Zopiclone, Zaleplon LSD (Hallucinogen & Gabapentinoids (Epilepsy & psychotomimetic) neuromuscular blockers) including: Gabapentin & Pregablin Benzodiazepines including: Diazepam, Tamazepam, Midazolam 1 2 Narcotic, opiate and opioids Overdose can result from any opiate used in either medical or abuse settings. Opiates depress the respiratory and circulatory system resulting in a reduced level of consciousness, hypotension and respiratory depression. Regardless of suspicion of opiate use, the paramedic must focus on the management of the patient’s airway, breathing and circulation. Heroin is a common illicit drug of abuse which can be injected, snorted or inhaled (smoked) and is responsible for the majority of opiate-related overdoses. 13 Opiate Overdose Management Determine the cause of altered level of consciousness and rule out easily treated metabolic conditions including hypoglycemia or diabetic ketoacidosis Naloxone (Narcan): Is a competitive antagonist which binds to opiate receptors preventing opiates from exerting their effects. Naloxone is administered parenterally either IV, IO, IM or SC. The focus of naloxone administration is to provide enough so that the patient regains their level of consciousness enough to protect their own airway. Rapid administration or administering too much naloxone can result in violent withdrawal resulting in agitation and vomiting (airway compromise) and risks to personal safety. 14 Opiate Overdose Management Presentation: Glass ampule containing 400 mcg naloxone hydrochloride Route of administration: IV / IM / IO / SC (JRCALC, 2019) Adult dose (12 years and above) Initial dose 400 mcg Repeat dose 400 mcg Dose interval 3 minutes Maximum dose 4,000 mcg or 10 ampules For further guidance on drug presentations, doses, indications and contra-indications read Abu Dhabi Civil Defence, PHECC and JRCALC drug guidance and formularies 10/15/2024 15 Central Nervous System (CNS) Depressants CNS depressants include benzodiazepines, barbiturates, anaesthetic agents, inhalational solvents and alcohol. CNS depressants cause; a depression of CNS function, drowsiness, confusion, disinhibition, impaired coordination and judgment, decreased blood pressure and respiration. 16 CNS Depressant Overdose Management Benzodiazepine intoxications are less severe than barbiturate overdose. Flumazenil is a specific benzodiazepine antagonist used to reverse the sedation and respiratory depression that often occur with benzodiazepine overdose. For barbiturate overdose management - activated charcoal is useful. 17 CNS Depressant Overdose Management Flumazenil is a competitive antagonist for benzodiazepine receptors. It is metabolized in the liver to inactive metabolites. Indications: Reversal of accidental or intentional benzodiazepine overdose causing respiratory depression. Dose: Adult over 18-years-old IV/IO 0.2 mg over 30 seconds / if no improvement a repeat dose of 0.3 mg over 30 seconds may be administered Under 18 years – 0.01 mg/kg (maximum dose 0.2 mg) (Abu Dhabi Civil Defence Authority, 2021) 18 Alcohol Intoxication Management Can effect body temperature, breathing, heart rate, and gag reflex. Patients with reduced GCS are at risk from aspiration and may lack capacity to consent or refuse treatment. Patients may suffer with seizures and/or delirium upon alcohol withdrawn when addicted. 10/15/2024 19  CNS Stimulants – Amphetamine, Methamphetamine & Cocaine Intoxication Are chemically similar to the body’s natural catecholamine's adrenaline, noradrenaline and dopamine. Cause significant peripheral effects as they are sympathomimetics- (hypertension, tachycardia, cardiac arrythmias (AMI/stroke), dilated pupils, excess activity, irritability, nervousness, anxiety, mood swings, violence, restlessness, seizures, excess temperature (pyrexia). 20 CNS Stimulant Intoxication Management CNS stimulants can cause tachycardia, hypertension, chest pain & myocardial ischemia. If ischemic chest pain is present, management should include oxygen, aspirin, GTN and a 12 lead ECG. Administer diazepam if the patient has severe chest pain (see local guidelines) If seizures occur administer benzodiazepines - follow local procedure. 10/15/2024 21 Common Medications Used in Overdose  Activated Charcoal Should be the first intervention in the management of oral overdose and poisoning. Activated charcoal reduces the absorption of poisons by providing a large surface area for ingested poisons to bind, reducing absorption. Administration of activated charcoal may induce nausea and vomiting and therefore should be administered following an appropriate risk assessment. Typically only administered within one hour of ingestion Activated charcoal is not recommended in all cases of ingestion as some drugs are not absorbed by activated charcoal. Contraindicated agents include: Cyanide, petroleum distillates, lithium, iron, ethanol, corrosive substances (JRCALC, 2019) 23  Paracetamol (acetaminophen) Overdose Paracetamol (Panadol) Acetaminophen (Tylenol) Be aware of paracetamol containing compound drugs which include codeine, such as co-codamol as these are derived from opioids and may also produce respiratory depression. Typical overdose presentations: Right upper quadrant abdominal pain, nausea, vomiting, jaundice, confusion – unconsciousness may develop Clinical overdose symptoms may be absent in some patient and therefor can be unreliable 24 Paracetamol Overdose Management Even in relatively small quantities, paracetamol overdose is dangerous and can result in severe liver and kidney damage. Patients who are malnourished or regularly drink alcohol are at an increased risk of liver damage. Initial care is the same as with other ill/injured patients Conservative management if stable Maintain airway Administer supplemental oxygen if hypoxic Place IV line Treat hypotension with IV bolus sodium chloride Consider activated charcoal (if ingestion within 1 hour) Consider naloxone with evidence of respiratory depression 10/15/2024 25 Cyclic Antidepressant Overdose Antidepressants are a common cause of overdose deaths Cyclic antidepressant overdoses are extremely dangerous in young children Clinical manifestations of cyclic antidepressant overdose include: CNS excitability, fever, pupil dilation, convulsions, depressed level of consciousness, arrhythmias, tachycardia, hypotension, tachycardia and respiratory depression 10/15/2024 26 Cyclic Antidepressant Overdose Management After the provision of initial supportive care, activated charcoal may be administered – if not contra-indicated. Cardiac arrhythmias are a life-threatening manifestation of cyclic antidepressant overdose. Many overdose patients have hypotension that does not respond to aggressive administration of IV fluid (require vasopressor medication). 10/15/2024 27 Cyclic Anti-depressant Overdose Management Continuous ECG monitoring Obtain IV access Seizures are common manifestation of overdose Can precede cardiac arrhythmia (ventricular tachycardia) Can be treated with diazepam (as per local guidelines) 10/15/2024 28 Beta-Blocker Overdose Beta-blockers are a class of medication that slow down the heart rate by blocking the action of hormones like adrenaline. Beta-blockers are commonly prescribed in tablet form. Many people take beta-blockers to treat heart- related conditions, such as: high blood pressure. Patients who overdose on beta-blockers usually have bradycardia, heart block and hypotension Some beta blockers also cause delirium, seizures, and coma Symptoms usually manifest within 6 hours 10/15/2024 29 Delirium Delirium is an acute disturbance of the mind, usually with an acute onset and has multiple causes. Symptoms include: euphoria, confusion, hallucinations, restlessness and agitation, lethargy, irritability or anger. Causes: chronic illness, metabolic disturbances, medication, infection, alcohol or drug intoxication and withdrawal. Beta-Blocker Overdose Management The mainstay of treatment should focus on the administration of atropine and IV fluids to improve tissue perfusion. However, atropine in most cases of beta-blocker overdose is inadequate. Administration of atropine after overdose only treats symptoms, not the underlying problems. Atropine Sulfate: (Presentations may vary) 12 years and above: 600 mcg rapid IV/IO bolus, repeated every 3-5 minutes – maximum dose 3 mg (3,000 mcg) 11 years and below – age adjusted doses – see local drug guidelines Sodium Chloride: (Presentations may vary) Adult: 250 ml bolus PRN (as required) – maximum dose 2 litres (2,000 ml) Children: 20 ml/kg (Age + 4 x 2=kg / Page for Age (JRCALC / Pediatric or Breselow tape) 31 Toxins Organophosphate or Nerve Agent Exposure Organophosphates are a class of chemicals found in insecticides and fertilizers. Subsequently altered for use as nerve agents Sarin and VX Gain access to the body through inhalation, ingestion and skin absorption Organophosphates inhibit the enzyme acetylcholinesterase This enzyme breaks down acetylcholine Without it, this causes overstimulation of parasympathetic nervous system, resulting in muscarinic and nicotinic effects. 33 Organophosphate or Nerve Agent Exposure The effects of muscarinic receptor blockage can be remembered by the mnemonic DUMBBELS. Muscarinic requires muscles. To build muscles, one needs DUMBBELS: Diarrhea Urination Miosis (contraction of pupils) Bradycardia Bronchospasm and bronchorrhea Emesis Lacrimation Salivation, secretion, and sweating 34  Organophosphate or Nerve Agent Exposure The effects of nicotinic receptor blockage can be remembered by the mnemonic MTWHF. Nicotinic is similar to the word nicotine, and smokers need nicotine every day of the week (MTWHF):​ Mydriasis (dilation of pupils)​ Tachycardia​ Weakness​ Hypertension and hyperglycemia​ Fasciculation (involuntary contractions, twitching)​ Organophosphate or Nerve Agent Exposure Management Symptoms of organophosphate intoxication can occur within 5 minutes Most dangerous manifestations are: Excessive respiratory secretions (bronchorrhea) Bronchospasm Respiratory insufficiency Imperative to secure the patient’s airway 36 Organophosphate or Nerve Agent Exposure Management Atropine should be used as an adjunct with oxygen, and only after adequate oxygenation has been achieved. Dosage and route of administration varies, you must check clinical guidelines. Routes of administration include IV/IO/IM No maximum dose, often large doses are required to reach ‘atropinisation’. Signs of atropinisation include; dry skin and mouth and an absence of bradycardia. (JRCALC, 2019) 37 Organophosphate or Nerve Agent Exposure Management DuoDote auto-injector (atropine combined with Pralidoxime) Is a self-contained auto-injector device designed for administration by ambulance personnel. Ambulance personnel should not rely solely on pharmacological agents for protection in such cases. The primary protection in such cases should be PPE. (JRCALC, 2019) 38 Paraquat Poisoning Paraquat is a toxic chemical found in herbicide or plant killers used in weed and grass control. It is generally found in liquid form. Paraquat has not been used in any CBRNE situations (CDC, 2018). Paraquat, if ingested in large quantities primarily effects the lungs, liver and kidneys. Symptoms include; gastrointestinal symptoms, nausea, vomiting, dehydration and hypotension. Management: Consider activated charcoal Unless hypoxemic avoid supplemental oxygen. If hypoxemic target saturations of 85-88%  Medications revision for next week’s class: GTN Morphine Clopidogrel References Andrew Pollak (2018). Nancy Caroline’s Emergency Care in the Streets, Eighth Edition. Jones & Bartlett Learning. Brown, S. N., Kumar, D. S., James, C., & Mark, J. (Eds.). (2019). JRCALC clinical guidelines 2019. Bridgwater: Class Professional.​ Guy J (2020). Pharmacology for the Prehospital Professional, Second Edition. Jones & Bartlett Learning. 41