Pharmacology Flashcards
What is the mechanism of action of cocaine?
Blocks uptake of dopamine, noradrenaline and serotonin
What is the first line management of cocaine induced MI?
Benzodiazepines + GTN
What is the mechanism of action of sildenafil?
Phosphodiesterase-5 inhibitors (enzyme that regulates blood flow in the penis and lungs)
What medications can cause hyperkalaemia if given with potassium-sparing diuretics?
ACE-I
What type of medication is amiloride?
Potassium-sparing diuretics
What immune changes can clozapine cause?
Neutropenia due to agranulocytosis
What immune cell changes can prednisolone cause?
Neutrophilia (promotes neutrophil maturation), reduced eosinophils
Give an example of a natural and a pharmacological mineralocorticoid
Aldosterone
fludrocortisone
Give an example of a natural and pharmacological glucocorticoid
Cortisol
Hydrocortisone, prednisolone
What are the features of a tricyclic overdose?
Convulsions, altered mental state, widened QRS, dilated pupils, dry, hot skin
What can be given in a TCA overdose?
Sodium bicarbonate
What can be given in a benzodiazepine overdose?
Flumazenil
What are the features of an benzodiazepine overdose?
hypotension, bradycardia, respiratory depression and coma
What medication can be used to reverse the effects of DOACs?
Andexanet alfa (modified factor Xa protein)
Which antibiotics lower the seizure threshold?
Quinolones - cipro and levofloxacin
What are the side effects of rifampicin?
Hepatitis, orange secretions, flu-like symptoms
What are the side effects of isoniazid?
Peripheral neuropathy, hepatitis, agranulocytosis
What are the side effects of ethambutol?
optic neuritis - and colour blindness (stop meds if this occurs)
What are the side effects of pyrazinamide?
hyperuricaemia, arthralgia, myalgia, hepatitis
What is the mechanism of action of metoclopramide?
dopamine agonist (reduces nausea), crosses BBB and causes hyperprolactinaemia
How do vasopressin analogues help in bleeding?
They cause vasoconstriction and increased systemic vascular resistance
What tests should be done before starting amiodarone?
TFT, LFT, U&E and CXR
What is the management of anaphylactic reaction to blood transfusion?
Transfusion termination, IM adrenaline, antihistamines, corticosteroids, bronchodilators and supportive care
What is the mechanism of action of alendronate?
It decreases osteoclastic bone resorption by binding to hydroxyapatite and causing apoptosis of osteoclasts
What is the action of 5-alpha reductase inhibitors?
block conversion of testosterone to dihydrotestosterone, can take time to improve prostate symptoms
(example - finasteride)
When does renal impairment occur in patients starting rampiril?
In those with bilateral renal artery stenosis
Give examples of some vitamin D analogues
Calcitriol and tacalcitol
Why are vitamin D analogues used in psoriasis?
They decrease cell division and differentiation, which decreases epidermalproliferation
Can you use topical vitamin D analogues in pregnant women?
NO
Which antiemetic is best for vertigo and dizziness?
Prochlorperazine
Which antiemetic is used to treat nausea and motion sickness?
Cyclizine or promethazine
What do TNF-alpha inhibitors do?
Immunosuppression
What side effect are you mainly worried about in those taking hydroxychloroquine?
Bull’s eye (central) retinopathy
Which medications commonly cause gingival hyperplasia?
phenytoin, ciclosporin, CCB (nifedipine)
What is the action of infliximab and etanercept?
TNF alpha inhibitor - for crohns or rheumatoid
What is the action of imatinib?
tyrosine kinase inhibitor - For GI tumours and CML
How long after taking digoxin should you measure blood concentration levels?
At least 6 hours after last dose
How long after taking lithium should you measure blood concentration levels?
12 hours post-dose
Which medications cause urinary retention?
opioids, tricyclics, anti-cholinergics and NSAIDs
What are the side effects of ciclosporin?
^ fluid, BP, K+, hair, gums, glucose
nephrotoxicity and hepatotoxicity
What is the characteristic symptom of digoxin toxicity?
yellowing of vision - xanthopsia, and reduced acuity (can get confusion, nausea and lethargy) and gynaecomastia
What is the main adverse effect of hydroxychloroquine?
Bull’s eye retinopathy
How does atropine work?
blocks parasympathetic action of the heart - increases HR and CO
What type of anaemia does methotrexate cause?
megaloblastic macrocytic - due to folate deficiency
Which calcium channel blockers are rate limiting and which are longer acting?
RL: verapamil or diltiazem
Longer acting: amlodipine, nifedipine
Which other heart medication should not be prescribed with beta blockers?
Rate limiting CCBs such as verapamil
How should bisphosphonates be taken?
with plenty of water while sitting or standing, on an empty stomach - at least 30 mins before breakfast, should be upright for 30 mins after taking
What are some side effects of SGLT-2 inhibitors?
recurrent urine infections, necrotising fasciitis
Name some somatostatin analogues
octreotide, lanreotide
Name some cortisol synthesis inhibitors
ketoconazole, metyrapone
What type of medication is indapamide?
thiazide-like diuretic
What are the features of a type A drug reaction?
Augmented reactions - dose related, common, predictable, related to pharmacology, unlikely to be fatal
What are the features of type B drug reactions?
B = Bizarre
not dose related, uncommon, unpredictable, not related to pharmacology, often fatal
What are the features of a type C drug reaction?
Chronic
uncommon, related to cumulative dose
What are the features of a type D drug reaction?
Delayed
uncommon, usually dose related, occurs after some time using the drug
What are the percentages for common, very common, uncommon and rare reactions?
Very common > 10%
Common 1%-10%
Uncommon 0.1% - 1%
Rare 0.01% - 0.1%
How does loperamide work?
It stimulates opioid receptors, but does not have systemic effects as is not absorbed through the gut
What are pharmacodynamics?
The effect of a Drug on the body or on another drug
What are pharmacokinetics?
The effect of the body on the drug
What can be caused by cocomitant use of aminoglycosides and loop diuretics?
Ototoxicity - effects are additive
What does Cytochrome P450 do?
It is involved in the metabolism and removal of drugs from the body
Which common medications induce CY P450?
Anticonvulsants, corticosteroids, some antimicrobials, St John’s Wort, cigarette smoke
What are some common inhibitors of CYPs?
Fluconazole, miconazole, erythromycin, grapefruit and cranberry juice, SSRIs, Omeprazole, erythromycin, ciprofloxacin
When can you not use eGFR?
In under 18s and pregnant people
Or people who’s kidney function is changing rapidly
When should you use creatinine clearance instead of eGFR?
-aged over 75
- on nephrotoxic drugs
- at extremes of muscle mass
- on medicine with a narrow therapeutic index
- on DOACs
Which drugs should be stopped in AKI?
ACEi, ARBs, NSAIDs, contrast, aminoglycosides and diuretics
What fluids should you use in AKI?
crystalloids - Hartmann’s unless hyperkalaemia
Sodium bicarbonate if serum bicarb < 20
Which type of diuretic should be used in fluid overload in AKI?
Loop diuretics - furosemide
Name some typical and atypical antipsychotics
typical: haloperidol, chlorpromazine
atypical: clozapine, risperidone, olanzapine
What are the side effects experienced with typical antipsychotics?
Parkinsonism, acute dystonia (torticollis, oculogyric crisis), akathisia (severe restlessness), tardive dyskinesia (late onset abnormal, involuntary movements).
antimuscarinic, weight gain, raised prolactin
What medication can be used to treat acute dystonia?
procyclidine
How late can you take a POP without it being an issue?
desogestrel - 12 hrs
traditional POP - 3 hrs
What medication should be started when taking an SSRI with an NSAID?
PPI
Which drugs should you not take with an SSRI?
- NSAIDS (okay with PPI), warfarin, heparin, aspirin, triptans (risk of SS), MAOIs (risk of SS)
Which antibiotics should not be used in those with stage 4 kidney disease?
Tetracyclines like doxycycline
What are the adverse effects of methotrexate?
pneumonitis
myelosuppresion
lung and liver fibrosis
What should be co-prescribed with methotrexate?
5mg folic acid once weekly
What do antipsychotics increase the risk of in the elderly?
Stroke and VTE
How much body weight is made up of water?
60% in males
55% in females
Percentage also decreases with age
How much fluid is in each body compartment?
Intracellular: 2/3rds
Extracellular: 1/3rd (75% interstitial, 25% intravascular)
What does an isotonic solution mean?
The osmolarity of the fluid is similar to that of blood (hartmanns, 0.9% NaCl)
Which solutions are hypertonic?
NaCl 3%, mannitol
When you give sodium chloride 0.9% which body spaces does the volume go?
25% to intravascular
75% to interstitial
none to cells
When you give glucose 5% where does it distribute to in the body?
It goes into all fluid spaces relative to their contributions of total body water
When you give a colloid fluid, where in the body does it distribute to?
It stays in the intravascular compartment
How much water should be given per day for maintenance?
25-30 ml/kg/day
20-25 ml/kg/day if frail or HF
Diarrhoea causes the loss of which electrolytes?
sodium, potassium and bicarb
Vomiting causes the loss of which electrolytes?
potassium, chloride and hydrogen
What is the minimum urine output you should aim for when giving maintenance fluids?
0.5ml/kg/hr
How often should you review fluids?
after each bolus in shock
every 12hrs in >3L fluids
daily in stable patients
What is the maximum infusion rate for potassium?
10nmol/hour
Which percentage of sodium chloride solution is closest to plasma?
0.18%
Which types of fluids are used for resuscitation fluids?
0.9% sodium chloride, Hartmann’s. plasma-lyte 148
What is the guidance for when someone needs resuscitation fluids?
NEWS2 > 5
urine output <0.5ml/kg/hr
CRT > 2
lactate > 2
HR > 100
BP < 100
Which medication can be used in severe pulmonary oedema?
Nitrates - reduce preload
What is the first line medication for cellulitis?
Flucloxacillin
What commonly causes high neutrophils?
bacterial infection, inflammation, steroids
What commonly causes low neutrophils?
Viral infection, chemo, radiotherapy, clozapine, carbimazole
What commonly causes high lymphocytes?
viral infections, lymphoma
Which drugs cause hypokalaemia?
loop and thiazide diuretics
Which drugs cause hyperkalaemia?
potassium sparing diuretics and ACE-I
What are the common features of getamicin and vancomycin toxicity?
ototoxicity and nephrotoxicity
What does a high INR mean?
Big INR = bleed
What neutrophil count indicates neutropenic sepsis?
< 1
Which group of people are beta blockers contraindicated in?
Asthmatics
What type of drug is diltiazem?
CCB
When should metformin be stopped?
In any circumstance with acute tissue ischaemia as can cause metabolic acidosis - MI, sepsis, AKI, dehydration
Contraindicated in BMI > 30
What are the features of ecstasy (MDMA) toxicity?
Hyperthermia, agitation, hyponatraemia, tachycardia, rhabdomyolysis
How do you measure therapeutic efficacy in heparin and warfarin?
Warfarin - wars outside - extrinsic pathway - PT (play tennis)
Heparin - stay in - intrinsic pathway - APTT (table tennis inside)
LMWH - no monitoring
what is the management of a beta blocker overdose?
glucagon
Tramadol increases the effect of which medication?
sSRIs - increased risk of serotonin syndrome
What do you need to monitor on carbimazole?
TFT and FBC - agranulocystosis
Which two common medications are taken at night?
Statins and amitriptyline
Which diabetes medication should be stopped in AKI?
Metformin
What is the mechanism of action of aspirin?
non-reversible COX-1 and COX-2 inhibitor
What are the most common side effects of CCBs?
Headache, flushing, ankle oedema
Which anticlotting drug do you use in severe renal impairment?
unfractionated heparin
What type of laxative should you give with opioid induced constipation?
Osmotic laxative - lactulose, macrogol
Name 3 LMWH
Enoxeparin, dalteparin, tinzaparin
How fast should you give IV glucose 10% infusion for hypoglycaemia?
Over less than 15 mins
Which medications need to be held when there is poor oral intake?
ACE-Is: Rampiril (AKI risk), ARBs
Metformin (acidosis)
How long before surgery are antiplatelets (such as aspirin) stopped?
7 days
How long before surgery should warfarin be stopped?
5 days - Vit K agonist if INR > 1.5 (see oral anticoagulants treatment summary)
What do you expect to see after starting Ramipril?
A small rise in creatinine < 20%
How should insulin doses be written on a prescription?
UNITs - in full words
What is the first line CCB used for hypertension?
Amlodipine
Which opioid is better in renal impairment?
Oxycodone (mild impairment) and fentanyl or buprenorphine in severe impairment
Is prednisolone safe to take when breastfeeding?
Yes
What are the common side effects of ACE-Is?
Angioedema, dry cough, hyperkalaemia
What are the features of serotonin syndrome?
everything up. hyperreflexia, rigidity, myoclonus, sweating, hyperthermia, confusion, dilated pupils, onset over hours
What is the management of serotonin syndrome?
IV fluids, benzodiazepines.
if severe: chlorpromazine (serotonin antagonists),
Which medications can precipitate lithium toxicity?
NSAIDs, ACE-I, ARBs, diuretics, metronidazole
Which medications commonly cause low magnesium?
diuretics, PPIs, diarrhoea, alcohol, hypokalaemia and hypercalcaemia
What are the LFTs in a paracetamol overdose?
Significantly raised AST and ALT
What is the management of a beta-blocker overdose?
Step on the GAS. Glucagon, atropine, saline
What is the action of aspirin?
COX-1 and 2 inhibitor, inhibits the production of thromboxane A2
Which drugs can cause serotonin syndrome?
ecstasy (and amphetamines), SSRI, MAOI
why do you get hyponatraemia when taking ecstasy?
SIADH or excess water consumption during taking ecstasy
What is the management of Carbon monoxide poisoning?
100% high flow oxygen through non-rebreather mask or hyperbaric oxygen
What are the common side effects of CCBs?
peripheral oedema due to arteriolar vasodilation, flushing, heart failure, hypotension
