Therapeutics and Toxicology Flashcards
Which medication to avoid in cocaine induced chest pain?
Bisoprolol.
Beta-blockers should be avoided in cocaine-induced chest pain. The rationale is that beta-antagonism may result in unopposed alpha-mediated coronary vasospasm.
Management for Amiodarone induced thyroxicosis Type 1?
AIT Type 1:
- Excess iodine-induced thyroid hormone synthesis.
- Goitre: Present
- Management: Carbimazole or potassium perchlorate
Amiodarone should be stopped if possible in patients who develop AIT
Management for Amiodarone induced thyroxicosis Type 2?
AIT Type 2:
- Amiodarone-related destructive thyroiditis.
- Goitre: Absent
- Management: Corticosteroids
Amiodarone should be stopped if possible in patients who develop AIT
Management for severe serotonin syndrome?
More severe cases of Serotonin Syndrome are managed using serotonin antagonists such as Cyproheptadine and Chlorpromazine.
Mx for cocaine toxicity?
Signs of cocaine toxicity with dilated pupils, hypertension, tachycardia, anxiety.
Benzodiazepines are generally first-line for most cocaine-related problems
Tx for Amiodarone induced hypothyroidism?
Treating the deficit with levothyroxine, Amiodarone can be continued.
ECG changes seen in TCA overdose (amitryptiline)?
ECG changes include:
- sinus tachycardia
- widening of QRS
- prolongation of QT interval
Widening of QRS > 100ms is associated with an increased risk of seizures whilst QRS > 160ms is associated with ventricular arrhythmias.
Mx for TCA overdose?
IV sodium bicarbonate.
Treatment for salicylate overdose?
Treatment:
1. General (ABC, charcoal)
2. Urinary alkalinization with intravenous sodium bicarbonate - enhances elimination of aspirin in the urine
3. Haemodialysis
Indications for haemodialysis in salicylate overdose:
- serum concentration > 700mg/L
- metabolic acidosis resistant to treatment
- acute renal failure
- pulmonary oedema
- seizures, coma
Linezolid should not be given with which class of medications?
In combination with serotonin agonists there is a risk of serotonin syndrome. Therefore, when using linezolid it must be considered to discontinue SSRIs.
How to screen for Paraquat overdose?
Urine dithionate testing.
Complication from IVIg treatment?
Aseptic Meningitis.
Aseptic meninigits occurs in 1% of patients with intravenous immunoglobulin. The key is to rule out any infective causes and to stop the immunoglobulin treatment until this is been done.
Features of lithium toxicity?
- Coarse tremor (a fine tremor is seen in therapeutic levels)
- Hyperreflexia
- Acute confusion
- Polyuria
- Seizure
- Coma
Mx for Cyanide poisoning?
Supportive measures: 100% oxygen
Definitive: Hydroxocobalamin (intravenously), also combination of amyl nitrite (inhaled), sodium nitrite (intravenously), and sodium thiosulfate (intravenously)
Adverse effect of Trastuzumab?
Trastuzumab (Herceptin) is a monoclonal antibody directed against the HER2/neu receptor.
Adverse effects:
- Flu-like symptoms and diarrhoea are common
- Cardiotoxicity
Tx for Methanol poisoning?
Methanol poisoning causes both the effects associated with alcohol (intoxication, nausea etc) and also specific visual problems, including blindness. These effects are thought to be secondary to the accumulation of formic acid.
- Fomepizole (competitive inhibitor of alcohol dehydrogenase) or ethanol
- Haemodialysis
- Cofactor therapy with Folinic acid to reduce ophthalmological complications
Treatment for LA toxicity?
Local anesthetic toxicity can be treated with IV 20% lipid emulsion.
Which medication can cause a slate grey appearance?
Amiodarone can cause a bluish-grey discolouration of the skin due to the deposition of lipofuscin pigments. This effect is particularly noticeable on sun-exposed areas such as the face and hands. The condition is usually reversible upon discontinuation of the drug, although it may take several months for the skin colour to return to normal.
Tramadol administered with SSRIs can cause what?
Serotonin syndrome.
This is because tramadol acts as a central serotonin reuptake inhibitor and so further increases serotonin levels.
Biochemical abnormality seen in ethylene glycol toxicity?
Ethylene glycol is a type of alcohol used as a coolant or antifreeze
Metabolic acidosis with high anion gap and high osmolar gap.
Symptoms of organophosphate poisoning? (insecticide poisoning)
Muscarinic side effects.
Salivation
Lacrimation
Urination
Defecation/diarrhoea
Cardiovascular: hypotension, Bradycardia
also: small pupils, muscle fasciculation
Mx: ATROPINE.
Which condition is gentamicin contraindicated in?
Myasthenia gravis.
How to determien dosing of gentamicin based on peak and troughs?
- Both peak (1 hour after administration) and trough levels (just before the next dose) are measured.
- If the trough (pre-dose) level is high the interval between the doses should be increased.
- If the peak (post-dose) level is high the dose should be decreased.
Mx for malignant hyperthermia?
- Condition often seen following administration of anaesthetic agents
characterised by hyperpyrexia and muscle rigidity. - Cause by excessive release of Ca2+ from the sarcoplasmic reticulum of skeletal muscle.
Mx: IV Dantrolene
Which overdoses can be haemodialysed?
BLAST
Barbiturates
Lithium
Alcohols e.g. ethylene glycol
Salicylates
Theophyllines
