Drugs of abuse and toxicity Flashcards
What is abstinence syndrome?
signs and symptoms that occur on withdrawal of a drug in dependent person
What is addiction?
compulsive drug-using behavior where the person uses the drug for personal satisfaction
What is a controlled substance?
drug deemed to have abuse liability
What is dependence?
signs and symptoms opposite of those caused when withdrawn from chronic use or abruptly lowered
What is a designer drug?
synthetic derivative of a drug with slightly modified structure but no major change in action
How does dopamine work in regard to addiction?
primary role in expression of reward – appears that most addictive drugs affect dopamine in the CNS
What is drug class I and its drugs?
no medical use, high addiction potential – flunitrazepam, heroin, LSD, mescaline, PCP, MDA, MDMA, STP, marijuana
What is drug class II and its drugs?
medical use and high addiction potential – amphetamines, cocaine, methylphenidate, short acting barbiturates, strong opiods
What is drug class III and its drugs?
medical use and moderate abuse potential – anabolic steroids, barbiturates, dronabinol, ketamine, sodium oxybate
What is drug class IV and its drugs?
medical use and low abuse potential, benzos, chloral hydrate, mild stimulants, most hypnotics, weak opiods
What are sedative-hypnotics?
Benzos (pams and lams), barbiturates (barbitals) and sodium oxybate (GHB), alcohol
What are the effects of sedative-hypnotics?
reduce inhibitions, suppress anxiety, produce relaxation – facilitation of GABA effects or enhance brain dopaminergic pathways
What are overdose signs on sedative-hypnotics?
slurred speech, drunken behavior, dilated pupils, weak and rapid pulse, clammy skin, shallow respiration, coma, death
What can potentiate the effect of the depressant of sedative-hypnotics?
opioid analgesics, antipsychotics, marijuana, drugs with sedatives
How do acute overdoses occur in sedative-hypnotic drugs?
depression of medullary, respiratory, and cardiovascular centers
How do you manage a sedative-hypnotic overdose?
maintenance of patient airway + ventilatory support
Flumazenil = benzodiazepine antidote but can cause seizures if too fast
not for barbiturates or alcohol
What does withdrawal look like for sedative-hypnotics?
anxiety, tremor, n/v, delirium, hallucinations, seizures
long term can have weight loss, tingling/numbing, headache
What is withdrawal treatment for sedative-hypnotics?
long activating sedative hypnotic followed by gradual dose reduction and prevent seizures
clonidine or propranolol may be used to suppress this
What can you use to make a patient stop drinking alcohol?
naltrexone, acamprosate, disulfuram cause very sick reaction to alcohol
What are the effects of opioids?
euphoria –> sedation, rapid tolerance dependence and addiction
po/smoking = milder effects
What are examples of opioids?
heroin, morphine, codiene, oxycodone, meperidine, fetanyl
What does an opioid overdose look like?
respiratory depression
How do you treat an opioid overdose?
naloxone and ventilatory support (airway!)
What are withdrawal symptoms for opioids?
lacrimation, rhinorrhea, yawning, sweating, weakness, goose flesh, n/v, tremors, hyperpnea (rarely fatal)
How can you help treat withdrawal from opioids?
replacement with pharmacologically similar drug and slow dose reduction, buprenorphine, use of naloxone to make more intense
neonates = special management
What do amphetamines do?
stimulate, increasing release of dopamine, nore, serotonin
What do stimulants cause?
euphoria and self-confidence
What can chronic meth stimulant use cause?
psychotic state with delusions, paranoia, picking
What are overdose signs for methamphetamine stimulants?
agitation, restlessness, tachycardia, hyperthemia, hyperreflexia, seizures
no antidote
What is chronic meth stimulant abuse associated with?
necrotizing arteritis
What are stimulant withdrawal symptoms?
increased appetite, sleepiness, exhaustion, depression
What do overdoses look like for cocaine?
stimulant too – common fatalities from arrhythmias, seizures, respiratory depressions. No antidote available either
What is associated with increased fetal morbidity and mortality?
cocaine use in pregnancy
How do you handle a poisoning situation?
supportive care – airway and blood pressure support, toxicology screenings
What are three procedures wildly used to reduce absorption of poisons from GI tract?
inducing emesis w/in 1 hr of ingestion*
gastric lavage w/in 1 hr of ingestion*
activated charcoal absorbs poison throughout
*Small intestine not cleared
What is the major cause of hepatic failure in the US?
acetaminophen toxicity
What is the metabolite of acetaminophen toxicity?
N-acetyl-p-benzoquinone imine (NAPQI) due to overload of pathway so forced into toxic metabolite
What is the antidote for severe APAP toxicity?
n-acetylcysteine (NAC)
What is methanol in that patients may ingest?
windshield and gas line antifreeze, fuel, rapid PO absorption
What makes methanol toxic?
metabolites – metabolized by alcohol dehydrogenase to form formaldehyde (problem)
What happens with methanol and ethylene glycol toxicity?
metabolic acidosis, glycoaldehyde, renal injury
What are two antidotes for methanol exposure?
ethanol and fomepizole, blocking the metabolism of alcohol dehydrogenase
What does cyanide do?
complete blockade of oxidative phosphorylation critically with cytochrome a3, resulting in loss of ATP synthesis —-> everything ceases to function
What are the antidotes for cyanide?
nithoidote: sodium nitrite IV and sodium thiosulfate IV
may cause significant HYPOtension, monitor SpO2, give high dose O2
cyanokit -hydroxycobalamin ** very high affinity for cyanide, faster option
What drug has a narrow therapeutic index?
Digoxin – toxicity resulting from lower cardiac conduction and heightened automaticity
What are overdose symptoms of digoxin?
unusual blind spots, color mismatch, irregular pulse, tachycardia
What is the antidote for a digoxin overdose?
digibind, digitalis antidote, digifab
What do you give to treat an arsenic exposure?
dimercaprol
What do you give to treat an iron exposure?
deferoxamine
What do you give to treat a lead exposure?
succimer, EDTA
What do you give to treat a mercury exposure?
succimer, dimercaprol
What is a chelator?
binding agent that suppresses chemical activity by forming cheleates – metal toxicity treatment relies on this
What is the antidote to warfarin?
phytonadione – vitamin K (orally)
How does warfarin work?
inhibits regeneration of Vitamin K through inhibiting reductase C1 and quinone reductase
