Cardiotoxicity Flashcards
Anthracycline - what are they?
Chemotherapeutic agents used to treat cancer
They have a complication with heart failure (2.4 fold increase? of congestive heart failure- in children)
Anthracycline - clinical signs and symptoms
Three main types - acute, early onset, late
.acute - sinus tachycardia/ arrhythmias
.early onset - symptoms of clinical heart failure, most common
.late - asymptomatic, lower ejection fraction, arrhythmias
Anthracycline - mechanism
forms free radicals to induce apoptosis
Anthracycline - antidote and management
before treatment, must assess baseline clinical cardiovascular examination.
Can be used it enalapril and ACEi
Affects the left ventricular function of the heart therefore must monitor the function of that side,
Cocaine - exposure and administration
Body packers . oral (alcohol can increase cocaine absorption) . smoking . snorting . intravenous
Cocaine - clinical signs and symptoms
Chest pain, SoB, dizziness, hypertension, left ventricular hypertrophy, palpitations
. Identification- urine toxicology, echocardiogram
Cocaine - mechanism
Sympathomimetic agent - neurotransmitter receptors on post-synaptic membrane are stimulated more,, prevents reuptake catecholamine
Cocaine - management
.acute - anti-platelet drug, alpha blockers, nitric-oxide mediated vasodilators
.chronic - amlodipine, ACEi, diuretic drugs
.Monitoring - drug history, temperature, bp, CT scan, BNP
THERE IS NO SPECIFIC PHARMACOLOGICAL ANTIDOTE FOR COCAINE OVERDOSE
Ecstasy - exposure, administration
Typically powder, pill or crystal (oral or snot) - others include rubbing into gums
Dose varies with individuals
Ecstasy - clinical signs and symptoms
Systemic - heightened sensation, euphoria, clenched jaw, uncontrolled body movements, excessive sweating, yellowish skin, restlessness
Ecstasy - clinical signs and symptoms
anxiety, loss of consciousness, chest pain, hypertension, confusion, seizures, headache
. may also lead to cardiac arrhythmia, fatality, myocardial necrosis
Ecstasy - mechanism
Myocyte necrosis with macrophage inflammatory response, or necrosis of contraction band in myocardium
cont.
Ecstasy - antidote, management
No specific treatment - withdrawal symptoms caused by serotonin deficiency
. SSRIs (selective serotonin reuptake inhibitors)
Overdose - rehydration and lowering body temperature
Monitoring - ECG, echocardiography, hepatic blood test, C-reactive protein
High relapse rate
Cyclophosphamide - what is it used for?
In treatment of cancer to supress the immune system
Cyclophosphamide - exposure
Chemotherapeutic agent, occupation and secondary exposure.
Cyclophosphamide - signs and symptoms
Alopecia, pul. fibrosis, syndrome of inappropriate anti-diuretic hormone secretion (SIADH)
Cyclophosphamide- Cardiotoxicity symptoms
Tachicardia, cardiac arrhythmias, SoB, chest pain, severe lethargy, dry cough
Cyclophosphamide - identification
ECG, listening to heart for an irregular rhythm.
Chest x-ray for heart enlargement or pulmonary oedema. Troponin blood test
Cyclophosphamide -mechanism
CYC metabolised by P450 in the liver –> oxidative damage –> cause multifactorial myocardial necrosis and myocarditis, cardiac tamponade
CYC- antidotes and management of side effects
Bladder bleeding - intermittent dosing, lots of fluids
Infertility - intermittent dosing
All risks are lower with a lower dosage
Cardiotoxicity - beta-blockers, ACE inhibitors, diuretics
CONTRAINDICATIONS: TERATONGENIC in pregnant women
Methamphetamine - what is it?
Strong CNS stimulant (recreational drug). Severe psychological withdrawal. Lots of deaths due to heart attack and stoke.
Methamphetamine - exposure
Powder - taken in binge-crash cycle (run), inhaled, smoked, swallowing a pill, snorting, injection
Can also be used to treat ADHD, narcolepsy, obesity in children and nasal decongestants - but used minimally due to high risk of misuse and addiction
Methamphetamine - Clinical signs and symptoms
Increased bp and breathing rate, body temp, dilated pupils, sleeplessness, paranoia, unpredictable behaviour, tremors, nausea, anxiety, depression, seizures, teeth grinding
Long term - microvascular hemmorrhage, eye damage, vision, mood disorders, impaired sexual motivation and performance.
Methamphetamine - mechanisms of cardiotoxicity
Increase release of catecholamines - adrenaline, serotonin, dopamine. Blocking the reuptake of these -> increase reactive oxygen species, mitochondrial injury and loss of myoglobin
Methamphetamine - antidotes and management
Monitoring - through IV, heart rate, medications to slow bp and ease anxiety, activated charcoal
Treatment - ACEis, beta adrenergic antagonists
Management - considered for heart transplant w severe symptoms
Herb-induced aconitine - what is it used for
Used in traditional Chinese medicine, fast acting toxin, there is no antidote, often mistaken for horseradish
Aconitine - symptoms
Presenting with paresthesias (numbness), muscle weakness, vomiting and cardiac abnormalities
Cardiovascular - palpitations, chest tightness, hypotension, ectopic
Neurologic - sensory and motor convulsions
Gastrointestinal - nausea, abdominal pain,
confusion and mania
Aconitine - mode of action
Sodium channel agonist. bonds sodium channels at receptor site of alpha subunit –> persistent activation
Aconitne- how does it cause bradycardia
Vagus nerve - innervates heart and slows rate (it is overstimulated)
Aconitine - treatment
Intravenous fluids for dehydration, activated charcoal, temporary pacemaker for severe bradycardia. atropine, dopamine for treating bradycardia
