Pharma/Tox/Emergency Flashcards
1
Q
Mechanism of action of bisphosphonates
A
Inhibits osteoclastic activity
Note: no effect on osteoblastic activity
2
Q
Treatment of beta blocker overdose
A
1st line atropine
2nd line glucagon
3
Q
Side effects of acetazolamide
A
MOA: inhibition of carbonic anhydrase
Metabolic acidosis (due to bicarb loss in the proximal and distal tubules, by inhibiting reabsorption)
HypoNa
Acute interstitial nephritis
Agranulocytosis and thrombocytopenia
4
Q
Deafness is a recognised complication of aspirin overdose T/F
A
True
5
Q
Management of aspirin overdose?
A
Gastric lavage up to 4 hours. Activated charcoal for sustained-release preperations
Plot level at 6 hours on normogram
Alkalisation of urine to aid drug excretion, close monitoring of electrolytes and pH , electrolyte repletion
6
Q
In aspirin overdose hypoventilation is common T/F
A
False - tachypnea is common.
Note: Phase 1 tachypnea directly stimulates the resp center -> resp alkalosis with a compensatory alkaline urine with bicarb and potassium loss
7
Q
Aspirin overdose is associated with hypoK and hyopglycaemia T/F
A
True
8
Q
When is activated charcoal indicated in treatment of paracetamol OD?
A
If >150mg/kg taken + presentation <1 hr since ingestion
9
Q
Melatonin is primarily metabolised in the kidney T/F
A
F - primarily met in the liver, hence can build up in those with hepatic impairment
10
Q
The MOA of melatonin is due to binding to MT1 and MT2 receptors T/F
A
True
Note: MT1 is in the suprachiasmatic nucleus of the ant hypothalamus and MT2 is in the retina
11
Q
Melatonin is C/I in those with epilepsy T/F
A
F - used to be thought to lower sz threshold but that was a poor study
12
Q
Where is digoxin eliminated?
A
70% is excreted unchanged in the urine
NB: in patients with CKD they should be treated with a decreased loading dose and decreased maintenance dose
13
Q
Patients on co trimoxazole (trimethoprim/sulfa) need to be monitored for what serious (but rare) side effect?
A
Cholestatic jaundice
14
Q
Code dose adrenaline?
A
0.1mg/kg 1:10,000
15
Q
What is the most common adverse effect of theophylline overdose?
A
Arrhythmia (it is a phosphodiesterase inhibitor but also acts on adenosine receptors such as on the AV node)
Note: other adverse effects agitation, restlessness or seizure
16
Q
What is the initial treatment of a TCA overdose?
A
IV sodium bicarbonate
If reliable airway, activated charcoal. If < 1 hr since ingestion can do gastric lavage (but will need to be intubated for this)
Note: leads to QRS prolongation and possible tachyarhythmias due to Na channel blocking in the myocardium. Na bicarb increases TCA protein binding, dislodges TCA from the Na channel and increased TCA elimination. TCA OD renders the myocardium relatively insensitive to tradition antiarrhythmics.
17
Q
What class of antidepressant is associated with GI bleeds?
A
SSRI
18
Q
Doses in adrenaline pens for anaphylaxis?
A
EpiPen Jr 0.15mg (< 6yrs)
EpiPen 0.3mg (6-12 yrs)
IM adrenaline 0.5mg ( >12 yrs)
19
Q
Indication for activated charcoal in drug overdose?
A
Within 1 hr of ingestion in a conscious patient (N +V are common post treatment so want to avoid in those with altered level of consciousness)
20
Q
Trimethoprim can cause an elevation in urea and Cr T/F
A
F - only causes elevation in Cr. It completes with Cr for secretion into the renal tubules so causes asymptomatic elevation in serum Cr with no change in urea. This is not true renal injury
21
Q
Where does cyclizine work?
A
Medulla oblongata
22
Q
Beta blockers can cause difficulty sleeping/insomnia T/F
A
True
Can also cause hypoglycaemia
23
Q
Side effect of prostaglandin
A
Apneoa
24
Q
Treatment of hereditary angio-edema?
A
C1 inhibitor or kallikrein inhibitor ecallantide
25
Where does methylphenidate work?
Basal ganglia - inhibition of dopamine reuptake
26
Rifampicin reduces the levels of statin T/F
T
Clarithromycin increases the levels of statins
27
Antibiotic that increased the levels of statins?
Clarithromycin
28
Steroids are CI in the treatment of TB meningitis T/F
F - they are an adjunct to treatment with triple antiTB therapy
29
Mechanism of action of ipratropium bromide?
Anti muscarine bronchodilator
SE: mydriasis (dilated pupils), skin flushing, hyperthermia, dry skin and mouth, urinary retention and agitation
30
Usual stat tx dose of oral dex in croup tx?
0.15mg/kg
31
In patients with renal impairment the loading dose of drugs needs to be decreased T/F
F - loading doses remain unchanged - loading doses are related to the volume of distribution which remains unchanged.
32
Conversion of oral morphine to subcut diamorphine and subcut morphine?
10mg oral morphine = 3mg diamorphine
10mg oral morphine = 5mg subcut morphine
33
In the tx of allergic rhinitis when is an oral antihistamine 1st line (instead of intranasal)
Oral is first line if:
- pt 2-5 yrs
- preference to take oral
- conjunctivitis is also present
34
What is the MOA of baclofen?
Agonist of GABA beta receptor
35
What is the MOA of benzos?
Increase the potency of GABA at the GABA alpha receptors (AKA +ve allosteric modulator of GABA alpha receptor)
36
What medications should be avoid in those with Juvenile myoclonic epilepsy?
Carbamazepine
Phenytoin
Oxcarbazepine
They can aggravate the sz
Note: sleep deprivation and alcohol consumption can precipitate the sz; EEG will show periodic 3Hz spikes
37
What is considered a staggered dose of paracetamol? How does this impact treatment?
Staggered dose is any dose taken over longer than an hour. At greater than an hour the normogram cannot be used and hence if there is concern that a person has ingested a significant amount they should just be treated with NAC
38
What is the best steroid to use in a pt who already has HTN?
Dexamethasone - has little to no mineralocorticoid activity
Note: methylpred and pred have significant mineralocorticoid activity
39
What is a Type A drug reaction?
"Augmented" - eg hypotension with a beta blocker or hypoglycaemia with insulin
40
What is a Type B drug reaction?
"Bizarre" - anaphylaxis
41
What is a Type C drug reaction?
"Continued" - lasts for a long time, eg visual field defects with vigabatrin
42
What is a Type D drug reaction?
"Delayed" - eg neutropenia with chemo
43
What is a Type E drug reaction?
"End of use" - withdrawal symptoms
44
MOA of beta lactams?
Inhibition cell wall synthesis
Vancomycin also works in this way
45
MOA of colistin (a polymyxin)
Disrupts cell membrane integrity
46
MOA of co-trimoxazole ?
Inhibition of folate synthesis
47
MOA of quinolones?
Inhibition of mRNA synthesis (eg ciprofloxacin)
48
MOA of aminoglycosides?
Inhibition of protein synthesis by binding to 30s ribosome subunit
49
Antidote to unfractionated heparin?
Protamine
Note: it has limited utility against LMWH
50
How many half lives are needed for the drug to be mostly cleared?
5
51
Side effects of montelukast?
Common: GI upset and rash
Rare: can precipitate Churg Strauss syndrome (can present with worsening asthma, neuropathy and a peripheral eosinophilia)
52
When should a digoxin level be checked?
Anytime more than 6 hours post dose.
53
What antibiotics are C/I in those with myasthenia gravis?
Aminoglycosides (such as gentamicin or amikacin) as they cause blockade of the NMJ and can exacerbate the condition
54
What is the preferred opioid to be used for analgesia in a syringe driver?
Diamorphine - it has a high solubility that allows a large dose to be given in a small volume (hence more practical than morphine)
55
Inhibition of hypoxanthine-guanine phosphoribosyltransferase what drug?
Mercaptopurine
56
Which antibiotics are most strongly associated with c dif/pseudomembranous colitis?
Cephalosporins ( eg cephalexin, cefuroxime) is strong
| Also common with clindamycin, ampicillin and amoxicillin
57
How does acute Vit A toxicity present?
Signs of raised ICP
58
Vincristine can have neurotoxicity side effects T/F
True - these can manifest as mobility issues, limb or back pain or cranial nerve neuropathies
Can also cause constipation, change in sensation, headaches
59
What type of drug is levomepromazine?
Antiemetic
Note: drowsiness is a side effect
60
Which is a stronger steroid HCT or prednisolone? How to convert HCT to pred
Prednisolone
Pred dose is 25% of the total dose of HCT. eg if on 25mg HCT this would be 25mg/4.
61
TB medication that can cause seizures in infant?
Isoniazid
62
Hoarse voice is a side effect of inhaled steroid use T/F
T - they deposit in the vocal cords leading to change in timbre
63
Coma is a feature of severe salicylate overdose T/F
F - can cause delirium or confusion but not typically coma
64
Sweating is a feature of salicylate overdose T/F
T - can interfere with the CNS autonomic function and increase basal metabolic rate leading to sweating
65
Common side effect of Efavirenz?
Depression (in those with no prior history of mental health problems)
Note: Rilpivirine can cause depression too but it is more likely in those which a hx of mental health problems
66
Common side effect of Rilpivirine?
Depression (more likely in those which a hx of mental health problems)
67
Most common side effect of Emtricitabine?
Rash and darkening of palms and sole
68
What lab abnormality does Cimetidine cause?
Elevation of creatinine without changing real GFR
69
What is the mechanism of cough due to ACE inhibitors?
Increased bradykinin
70
When given IV cotrimoxazole should be given as a slow IV bolus or an infusion?
As an infusion, preparation is very alkaline and hence can be caustic if given as a bolus
Note: although preferable to give via a central line can be given via a peripheral if it is diluted enough
71
Gentamycin gram + or gram -ve coverage?
Gram -ve only
72
Typical anticholinergic side effects?
Tachycardia
Pupil dilatation (mydriasis)
Dry mucus membranes
Urinary retention
73
HypoNa in MDMA ingestion can be due to SIADH T/F
True - can also be due to excessive fluid intake
74
HypoNa is the most common cause of death in MDMA overdose T/F
F - arrhythmia is most common
75
What are indications for hyperbaric O2 in carbon monoxide poisoning?
1. CV dysfxn
2. Pregnant (esp if carboxyHb >10%)
3. CarboxyHb > 20%
4. Unconscious / episode of syncope
5. Neuro/psych features (excluding HA)
76
Is bradycardia a characteristic feature of opioid overdose?
Yes
77
2 drugs that can cause hyperventilation in overdose?
Theophyline
| Salicylates
78
LSD is associated with serotonin syndrome T/F
F - LSD is not
Note: MDMA is assoc with serotonin syndrome
79
Typical features of serotonin syndrome?
```
Sweating
Agitation
Tachycardia
Dilated pupils
Muscle rigidity
Nausea, diarrhoea
In severe cases: seizures, clonus
```
80
Mechanism of action of loop diuretic is on the Na-K-Cl co transporter or the Na-Cl symporter
Na-K-Cl co transporter
81
Mechanism of action of thiazide diuretic is on the Na-K-Cl co transporter or the Na-Cl symporter
Na-Cl symporter
82
Seizures occur in about 50% of patients presenting with an NSAID overdose T/F
F - occurs in about 10-20%. It is more common in patients who have taken mefenamic acid
83
What are the main side effects of NSAID overdose?
Common: mild GI - epigastric tenderness, nausea, emesis and diarrhoea (due to inhibition of cycle-oxygenase mostly)
Large overdoses can also have drowsiness, coma , cerebellar signs and seizures. AKI and cardiorespiratory arrest, hypothrombinaemia
84
Desferrioxamine IV is a chelator used for what type of poisoning?
Significant iron overdose
85
Common side effects of cyclosporin?
Chronic interstitial nephritis
Hypertrichosis
Gum hypertrophy
Note: phenytoin also causes gum hypertrophy
86
In a patient starting on MTX NSAIDs use should be avoided, why?
NSAIDs can result in AKI or just mildly decreased kidney function. MTX relies on renal excretion and hence even a small decrease in kidney function can result in increased toxicity
87
In terms of teratogenic effects thalidomide causes phocomelia T/F
T - aka abnormalities of the limbs
88
What drug is known to cause chondrodysplasia punctata in the foetus?
Warfarin - these are skeletal abnormalities with punctate calcification of the cartilage of the epiphyses, larynx and trachea
89
What is the MOA of bosentan?
Endothelin receptor antagonist
Nore: endothelin is a potent vasoconstrictor, it is a polypeptide
90
What TB drug is known to cause red/orange discolouration of bodily fluids?
Rifampacin
91
What HIV medications are closely associated with fat loss/lipoatrophy?
Zidovudine, stavudine (nucleoside RTIs)
92
How should amiodarone be administered to a neonate
IV (ideally via a central line) diluted in 5% glucose
Note: it is incompatible with NaCl ; needs to be diluted as it is alkaline and can cause pain and inflammation on infusion if not
Oral abs in the neonatal period is unpredictable and in general abs is very slow
93
What labs are the best markers of severity in paracetamol overdose?
INR
pH
Serum Creatinine
94
What is the mechanism of action of terlipressin?
Vasopressin analogue - hence causes vasoconstriction of the splanchnic blood vessels.
95
What is the mechanism of action of activated charcoal in treatment of drug overdose?
Interrupts a drug's enterohepatic circulation
96
What is the main reaction involved in the normal metabolism of paracetamol?
Glucuronidation
Note: when this pathway becomes overwhelmed in overdose cyto p450 pathway is used
97
What is the appropriate mgmt of a patient with an elevated gent trough and why?
```
trough = renal clearance
peak = drug dose
```
--> keep dosing the same but less often so as to allow drug to still reach therapeutic peak and also give enough time to clear
98
What is a good inotrope to use if you do not want to increase HR?
Phenylephrine as it is purely alpha adrenergic and hence raises BP without effect on HR
99
What is the mechanism of action of dobutamine?
Pure beta 1 adrenergic --> increases HR and force of contraction
Note: good for cardiogenic shock
100
Why should codeine be used with caution in those < 6 yrs old/avoided if possible?
It metabolises v quickly to morphine
101
Which atypical antipsychotic has particularly high likelihood to cause the side effect of hyperprolactinaemia?
Risperidone
Note: other SEs: dyslipidaemia, abnormal LFTs, insulin resistance, increased BP, prolonged QTc, fatigue, lethargy, increased appetite, drooling
102
Statins block de novo cholesterol synthesis T/F
T - hmg CoA reductase inhibitor
103
What is the MOA of sildenafil?
Inhibits breakdown of cGMP (guanosine monophosphate) --> increasing cGMP
104
How does glucagon function in treatment of beta blocker overdose?
Increases cAMP (adenosine monophosphate) by direct stimulation of adenylate cyclase in the cardiac mycytes --> increasing rate and force of cardiac contraction
Note: mode of action is independent of the blocked beta receptors
105
What is the MOA of aminophylline and theophylline?
Phosphodiesterase inhibitor and adenosine antagonist
106
Leucopenia is a side effect of lithium T/F
F - leucocytosis
107
Leucocytosis is a side effect of lithium T/F
T
108
Acetazolamide can cause what acid base abnormality?
Met acidosis
Note: loop, thiazides cause alkalosis
109
Paracetamol is a non selective inhibitor of COX1 and 2 enzymes. T/F
F - inhibits cox 1 --> resulting in reduced prostaglandin synthesis
110
Dosing of mannitol and hypertonic saline for treatment of cerebral oedema
Mannitol 1g/kg (20%)
2.5 -5ml/kg hypertonic saline
Both over 10-15 minutes
111
On what cells do PPIs work?
Parietal cells
Blocks the H/K ATP pump
112
Where does mannitol act?
Entire loop of henle
113
For a child weighing 35kg the dose of NAC is 150mg/kg in 100ml 5% glucose T/F
T - for a child weighing 20-39kg this is the dose
114
For a child weighing 10kg what is the dose of NAC
150mg/kg in 3ml 5% glucose
This is the dose for a child < 20 kg
115
For a child weighing 45kg the dose of NAC is 150mg/kg in 100ml 5% glucose T/F
F - the NAC should be in 200ml, this is the dosing for anyone > 40kg (adult dosing)
116
NAC works in paracetamol overdose by reducing the formation or the circulation of toxic metabolites?
It reduces the circulation
117
Gum hypertrophy is a side effect of nifedipine T/F
T
118
Supportive care and antipyretics are the mainstay of treatment of serotonin syndrome T/F
F - supportive care is the mainstay of treatment but anti pyretics do not work (as the hyperthermia results from increased muscular activity)
Note: benzo and a serotonin antagonists (such as cyproheptadine) may help
119
What is flunitrazepam also known as?
Rohypnol
Drug class: benzo. Not approved for us in the US and it's import is banned
Note: GHB (gamma hydroxybutyrate) is another date rate drug)
120
In gynaecomastia caused by exogenous steroid use what is the prolactin level?
Prolactin is normal
121
Phencyclidine and heroin overdose can both cause coma, what is the clinical difference?
PCP coma does not have associated respiratory depression
122
What is the treatment of clonidine overdose?
Supportive
123
Presentation of clonidine overdose?
CNS and resp depression, hypotension, bradycardia and pinpoint pupils
Similar to opioid toxicity but would not expect as much hypotension with opioid overdose
124
What medication can be used to treat tics in those with ADHD?
Clonidine or guanfacine
Note : treatment of ADHD with stimulants may unmask an underlying tic disorder or worsen existing tics. It stimulant is working, continue it and add clonidine or guanfacine
125
Features of ingestion of synthetic cathinones?
| Tx?
AKA bath salts
Features - sympathomimetic syndrome with stimulant and hallucinogenic properties. Diaphoresis, tachycardia, mydriasis with anxiety, agitation, paranoid delusions and seizure.
Benzos for pyschomotor agitation
126
Excessive salivation, involuntary tongue and limb movements, anxiety and laryngospasm are adverse effects of what drug abuse?
Ketamine
127
Slurred speech, lacrimation, salivation, perioral rash and stupor - what drug abuse?
Inhalant
Note: also associated with pneumothorax and pneumomediastinium
128
Warfarin leads to a reduction in protein c and s T/F
T - also prothrombin (F2), F7, F9, F10
129
Features of in utero methotrexate exposure?
Craniosynostosis and/or skeletal abnormalities such as limb defects
Can be mis diagnosed as trisomy 18
130
Features of in utero phenytoin exposure?
```
Dysmorphic features such as arched eyebrows, hypertelorism and a short upturned nose
Orofacial cleft
Shortened digits with hypo plastic nails
VSD
GU defects
```
131
In utero exposure to retinoid acid is associated with facial nerve palsy T/F
T
Also associated with microcephaly, external auditory canal anomalies, cardiac defects, thymic hypoplasia and GU malformations
132
What is the MOA of organophosphate poisoning?
Inhibits anticholinestarase --> prevents the degradation of acetylcholine
133
Clinical features and tx of organophosphate poisoning?
```
DUMBBELLS
Diarrhoea
Urination
Myosis
Bradycardia
Bronchospasm
Emesis
Lacrimation
Lethargy
Salivation/Seizures
```
Tx: atropine and pralidoxime
134
Brown recluse vs black widow spider bite?
Black widow: typically the bite is painful and then due to neurotoxin develop muscle rigidity and pain (local or spreads to abdo and back); can also have vomiting malaise and HTN
Brown recluse: bite typically not noticed; haemorrhagic blister that turned into a necrotic ulcer. Rarely can have systemic side effects such as fever, nausea, emesis and haemolysis.
Tx for both is supportive
135
Features of TCA overdose?
ECG changes such as QRS widening and conduction delays
Hypotension
Anticholingeric features - hyperthermia, flushing dilated pupils, urinary retention, ileus
Seizures, hyperactive reflexes, myoclonus
136
In a drowning event with asystole, children submerged in warm water have a better change of survival T/F
F - those submerged in water < 10 C (50 F) have a better change of survival
137
In a downing event both submersion time > 10 minutes and time to resus > 10 min are associated with poor prognosis T/F
T
Note: other factors assoc with poor prognosis asystole and resus time >25 min
138
Duration of cardiac monitoring after TCA ingestion?
Min 6 -8 hours
| If symptomatic/abnormal need monitoring until 24 hrs post normalisation
139
A scorpion sting usually results in a small painful vesicle T/F
F - usually leaves not mark but is painful
140
Clinical presentation of a scorpion sting?
Pain at site of sting (but no mark) most commonly
More severe features - muscle fasciculation and rapid dyscongugate eye movement (can be mistaken for seizure); agitation; salivation; response distress and extreme tachycardia
141
At what age doe the highest rate of child maltreatment occur?
Birth - 1 yr old
142
What finding on UA is consistent with ethylene glycol (antifreeze) ingestion?
Ca oxalate crystals
Note: oxalic acid is a metabolite of ethylene glycol
143
Which is associated with rhabdomyolysis, PCP or LSD?
PCP
144
Contra indications to ketamine?
Age < 3 months (and relative CI to age < 12 months)
Psychosis
Note: does not cause hypotension
145
How long does it typically take a drug to reach therapeutic steady state (> 95%) if no loading dose is given?
5 doses
Eg if half life is 6 hours it will take 30 hours (5 x 6)
146
Levothyroxine should be take with breakfast T/F
F - should be taken on an empty stomach as requires an acidic environment to be absorbed.
Most azole antifungals and Fe should also be taken on empty stomach
147
In what situation can an involuntary drug test be done?
In a emergency - such as after an accident
Attempted suicide
Unexplained seizure
148
Propofol is CI in those with what allergies?
Soy or egg
149
PPIs lead to an increased risk of what?
Pneumonia
C diff
HypoMg
