Pharmacology Flashcards
Which drugs cause impaired glucose tolerance?
TASTINg Sugar (impaired glucose tolerance)
Thiazides Antiphychotics Steroids T cell in inhibitors (tacrolimus |&| cyclosporin) Interferon alpha Nicotinic acid (niacin N3)
What is the MOA of aspirin?
IRreversible inhibition of COX 1 and 2
What does aspirin increase the bodies reaction to? (three other drugs)
oral hypoglycaemics
warfarin
steroids
Tx of cyanide poisoning?
B12 (binds to cyanide to stop it being dangerous)
In paracetamol OD, what marker after 24hrs would make you consider the patient for a liver transplant?
An arterial pH <7.3, 24 hours after ingestion
How ‘staggered’ qualifies a staggered OD?
an overdose is considered staggered if all the tablets were not taken within 1 hour
What is the MOA of metformin?
activation of the AMP-activated protein kinase (AMPK)
What class of medication is metformin in?
Biguanides
What is the MOA of HIT?
antibodies form against complexes of platelet factor 4 (PF4) and heparin
What is the MOA of allopurinol?
AllopurINol = INhibits Xanthine Oxidase
Main troublesome SE of Mg?
Diarrhoea
Causes of low Mg?
HypoMAGNesia
M = metabolic: Gitelmans + Bartters A = alcohol G = gut: diarrhoea N = nutrition: TPN
Also drugs: thiazides
Electrolytes: hypoK, hyperCa
MAGNet
E = electrolytes
T = thiazides/loop/PPIs
Patients at a high risk of severe cutaneous adverse reaction should be screened for what allele?
the HLA-B *5801 allele
What do you need to be careful of co-prescribing with allopurinol and why?
Azathioprine
Because azathioprine breaks down into the active compound 6-mercaptopurine. This is usually further broken down by Xanthine Oxidase. Therefore when allopurinol stops XO working it can lead to v high levels of 6-mercaptopurine.
What other drugs need careful co-prescribing with allopurinol?
Cyclophosphamide
allopurinol reduces renal clearance, therefore may cause marrow toxicity
Theophylline
allopurinol causes an increase in plasma concentration of theophylline by inhibiting its breakdown
SEs of quinolones?
Tendon damage Lengthens QT (think stomachs Ea) LOWERS the seizure threshold in epilepsy
CIs for quinolones?
Pregnancy + G6PD
Lithium therapeutic range?
0.4-1
What can precipitate lithium toxicity?
Not diluted: dehydration
Not excreted: renal failure
drugs: diuretics (especially thiazides), ACEi/ARBs, NSAIDs and metronidazole
Same DAMN drugs are nephrotoxic but with metro rather than metformin
SEs of lithium use and signs of toxicity?
SE: Nausea Fine tremor Weight gain + oedema Polydipsia + polyuria Hypothyroidism
Toxicity: Vomiting Coarse tremor Diarrhoea Slurred speech/ataxia/confusion Convulsions/coma
Treatment of lithium toxicity?
IV fluids
Haemodialysis in severe toxicity
sodium bicarbonate is sometimes used but there is limited evidence to support this
What are the effects of excessive Ach?
DUMBELS Diarrhoea Urination Miosis/muscle weakness Bronchorrhea/Bradycardia Emesis Lacrimation Salivation/sweating
Management of organophosphate poisoning?
Atropine
What is the MOA of sodium bicarb in Tx of lithium toxicity?
Increases urine alkalinity
When is quinine given if not for its antimalarial properties?
Leg cramps
4 hallmark symptoms and two effects of quinine overdose?
Hallmarks are tinnitus, visual blurring (think retinopathy), flushed and dry skin and abdominal pain
Effects: cardiac arrhythmias, hypoglycaemia
Name of quinine OD?
Cinchonism
Adverse effects of ciclosporin?
(note how everything is increased - fluid, BP, K+, hair, gums, glucose) nephrotoxicity hepatotoxicity fluid retention HTN hyperkalaemia hypertrichosis gingival hyperplasia tremor impaired glucose tolerance hyperlipidaemia increased susceptibility to severe infection
How to treat adrenaline induced ischaemia e.g. epipen to the hand?
Adrenaline induced ischaemia - phentolamine (alpha antagonist)
How to remember the general classes of anti-arrhythmic drugs?
Son of a B*tch is Politically Correct 1 Sodium blocker 2 Beta blocker 3 Potassium blocker 4 calcium blocker
How to remember the class 1 anti-arrythmics?
Double Quarter Pounder with Tomato Lettuce Mayo, also Fries Please
Disopyramide Quinidine Procainamide(Ia)/ Tocainide Lidocaine Mexilitine(Ib)/ Flecainide Propafenone (Ic)
Drugs that are CI in pregnancy?
CATS CRAWSS
Abs: Quinolones (ciprofloxacin) Aminoglycosides - Ototoxicity Tetracyclines - Discoloured teeth Sulphonamides + trimethoprim
Cytotoxic agents Retinoids (topical + PO) ACEi/ARBs - renal dysgenesis/CF abnormalities Warfarin - CF abnormalities Statins Sulfonylureas
What is the MOA of cocaine?
cocaine blocks the uptake of dopamine, noradrenaline and serotonin
SEs of cocaine use?
Cocaine - Eric Clapton
E - Elevated BP
R - Rhabdomyolysis
I - Ischaemic Collitis
C - Coronary vasospasm
C - convulsions L - long QT and QRS A - Aortic dissection P - Psychosis Ton - Tone (increases) / reflexes (increases)
Management of cocaine OD? With CP? with HTN?
Benzodiazepines
CP - GTN spray
HTN - Na nitroprusside
MOA of cyclosporin/tacrolimus?
Ciclosporin + tacrolimus: inhibit calcineurin thus decreasing IL-2
What is the MOA of cyanide?
Cyanide inhibits the enzyme cytochrome c oxidase, resulting in cessation of the mitochondrial electron transfer chain.
Think all ‘c’s
Causes of drug induced photosensitivity?
SEE - ciprofloxacin H - hypoglycaemics - sulphonylureas (i) S - sulphonamides T - tetracyclines, thiazides A - amiodarone N - NSAIDs e.g. piroxicam
What would you try if metformin can’t be tolerated in T2 DM?
MR metformin
Two examples of drugs that work on nuclear receptors?
Prednisolone
Levothyroxine
Drugs which can be cleared with haemodialysis?
BLAST
Barbiturate Lithium Alcohol (inc methanol, ethylene glycol) Salicylates Theophyllines (charcoal haemoperfusion is preferable)
What problem in the kidneys can aminoglycosides cause?
Acute tubular necrosis
How quickly can you titrate metformin?
Earliest one week d/t risk of diarrhoea
Treatment for tricyclic OD?
Bicarbonates
TCA OD symptoms?
Anticholinergic: dry mouth, dilated pupils, agitation, sinus tachycardia, blurred vision, urinary retention
Features of severe poisoning include:
arrhythmias (can cause prolonged QT/VT)
seizures + coma
Drugs causing ocular problems?
Cataracts/corneal opacities/optic neuritis/retinopathy
Cataracts: steroids Corneal opacities: amiodarone, indomethacin Optic neuritis: ethambutol amiodarone metronidazole Retinopathy: chloroquine, quinine
SEs of TB drugs?
Rifampicin -> Orange bodily fluids, rash, hepatotoxicity, drug interactions
Isoniazid -> Peripheral neuropathy, psychosis, hepatotoxicity
Pyrazinamide -> Arthralgia, gout, hepatotoxicity, nausea
Ethambutol -> Optic neuritis, rash
RIP: Liver
Drugs causing urticarial rash?
NAPPY Nsaid Aspirin Penicillin o(PY)iates
What may be protective if taken with a paracetamol OD?
Acute alcohol intake
What increases the toxic effect of paracetamol (drugs)?
liver enzyme-inducing drugs (rifampicin, phenytoin, carbamazepine, chronic alcohol excess, St John’s Wort)
Drug induced thrombocytopaenia?
QANADAH quinine abciximab NSAIDs diuretics: furosemide antibiotics: penicillins, sulphonamides, rifampicin anticonvulsants: carbamazepine, valproate heparin
Common drugs to cause DRESS syndrome?
ALLOPURINOL, anti-epileptics, antibiotics, immunosuppressants, HIV treatment and NSAIDS
Symptoms of DRESS syndrome?
extensive skin rash, high fever, and organ involvement, supported by a finding of eosinophilia and abnormal liver function tests
What does DRESS mean?
drug reaction with eosinophilia and systemic symptoms
Drugs that may precipitate an attack of acute intermittent porphyria?
She Has Belly Aches Because Of porphyria: Sulphonamides Halothane Barbiturates Alcohol Benzodiazepines OCP
When to take therapeutic drug levels for lithium, ciclosporin, digoxin and phenytoin?
Phenytoin + ciclosporin - just before dose
Digoxin - 6hrs post-dose
Lithium - 12hrs post-dose
i have a Date @ 6, so i will be Late @ 12.
Call before you check and PHone if in doubt.
SEs of verapamil?
Heart failure Ankle swelling Flushing Headaches CONSTIPATION
How to treat acute dystonic reactions e.g. oculogyric crisis?
benztropine or procyclidine
What is Ethylene glycol?
Antifreeze
Features of antifreeze poisoning?
Stage 1: symptoms similar to alcohol intoxication: confusion, slurred speech, dizziness
Stage 2: metabolic acidosis with high anion gap and high osmolar gap. Also tachycardia, hypertension
Stage 3: acute kidney injury
Management of ethylene glycol poisoning?
Fomepizole
MOA of fomepizole?
competitive inhibition of alcohol dehydrogenase
Other than acidosis, what three factors are needed for liver transplant consideration following paracetamol OD?
All of the following:
prothrombin time > 100 seconds
creatinine > 300 µmol/l
grade III or IV encephalopathy
Which one of the following enzymes is involved in phase I drug metabolism?
Alcohol dehydrogenase
Macrolide SEs?
prolongation of the QT interval
GI side-effects are common. Nausea is less with clarithromycin than erythromycin
cholestatic jaundice: risk may be reduced if erythromycin stearate is used
P450 inhibitor
azithromycin is associated with hearing loss and tinnitus
Drugs that cause photosensitivity?
SEE (C) HiS TAN
cipro hypoglycaemics - sulphonylureas sulphonamides tetracylines, thiazides amiodarone nsaids
Which two medications can be given to prevent alcohol ingestion in alcoholics?
Acamprosate - decreases cravings
Disulfiram - blocks alc metabolism which induces an accumulation of acetaldehyde leading to headaches, flushing and nausea
aCam - cravings
diSul - sick
What is the MOA of benzos?
ENHANCE the effect of the INHibitory GABA neurotransmitter by increasing the FREQUENCY of chloride channels
How do you withdraw benzos if people are dependent on them?
steps of about 1/8 (range 1/10 to 1/4) of the daily dose every fortnight
What is the MOA of Metoclopramide and Domperidone?
Dopamine receptor ANtagonists
Adverse effects of dopamine agonists?
nausea/vomiting
postural hypotension
hallucinations
daytime somnolence
Which electrolyte abnormalities can predispose you to digoxin toxicity?
Low pH, temp, K, magnesium, thyroid
High Ca, Na
Think crisp packets (ie PKT) are always half-filled with air empty (ie MT) MT PKT (empty ie low) - Magnesium, Temp, pH, Potassium (k+), thyroid
Fizzy drinks are always full (or high) and come in a CaN
CaN - Calcium and Sodium (Na)
Digoxin MOA?
Inhibits the Na+/K+ ATPase pump
Treatment of lidocaine toxicity?
IV 20% lipid emulsion
Possible treatment for hyperthermia linked to ecstasy use?
dantrolene may be used for hyperthermia if simple measures fail
How to calculate the anion gap?
[Na+] + [K+]} - {[HCO3-] + [Cl-]
Best anti-sickness for motion sickness?
hyoscine > cyclizine > promethazine
Adverse effect of octreotide?
gallstones (secondary to biliary stasis)
What are patients receiving CHOP chemo particularly at risk of?
Tumour lysis syndrome
Give allopurinol
Which antibiotics lower the seizure threshold?
Quinolones
What is the life-threatening dose of paracetamol?
> 12g (24 tablets)
Ciclosporin side-effects?
everything is increased - fluid, BP, K+, hair, gums, glucose
Blood test to help differentiate between CO and cyanide poisoning?
Very high lactate in cyanide, not in CO
Antibiotics to avoid in renal failure?
tetracycline, nitrofurantoin
What would P450 enzyme inducers do in the event of a paracetamol overdose?
Increase the action of p450, therefore breaking down paracetamol into its toxic metabolites
What is the difference between T1 and T2 amiodarone induced thyrotoxicosis?
T1: Excess iodine-induced thyroid hormone synthesis Goitre
Management: Carbimazole or potassium perchlorate
T2: Amiodarone-related destructive thyroiditis
Absent goitre
Mx: Corticosteroids
What is MOA of tamoxifen?
Selective oEstrogen Receptor Modulator (SERM)
Acts as an oestrogen receptor antagonist and partial agonist
What are the adverse effects of tamoxifen?
menstrual disturbance: vaginal bleeding, amenorrhoea
hot flushes - 3% of patients stop taking tamoxifen due to climacteric side-effects
venous thromboembolism
endometrial cancer
What class of drug is Ondansetron in?
5-HT3 receptor antagonist
Name two 5HT receptor agonists?
Sumatriptan (5-HT1D)
Ergotamine (5-HT1)
What is the role alpha-1 receptor and example of agonists + antagonists?
Mainly post-synaptic
Vasoconstriction
GI SM constriction
Hepatic glycogenolysis
Agonist: phenylephrine
Antagonist: doxazosin (alpha-1a -> tamsulosin)
What is the role alpha-2 receptor and example of agonists + antagonists?
Mainly pre-synaptic
insulin inhibitor
platelet aggregation
Agonist: clonidine
Antagonist: yohimbine
What is the role beta-1 receptor and example of agonists + antagonists?
HEART
Increases HR and force
Agonist: dobutamine
Antagonist: atenolol
What is the role beta-2 receptor and example of agonists + antagonists?
LUNG + SM + SKELETAL MUSCLE
Bronchodilation
Vasodilation
Increased muscle contractions
Agonist: salbutamol
What is the role beta-3 receptor?
Lipolysis
Example of alpha 1+2 antagonist, beta 1+2 antagonist, and generalised alpha and beta antagonist?
Alpha 1+2 antagonist - phenoxybenzamine
Beta 1+2 antagonist - propranolol
Generalised alpha and beta antagonist - carvediolol and labetalol
What occurs in phase 1 drug metabolism, where, and what enzymes are involved?
Oxidation, reduction, hydrolysis
p450 enzymes, alcohol dehydrogenase
Usually occurs in the liver
What occurs in phase 2 drug metabolism and where?
Conjugation
In the liver
Which drugs are excreted by zero order kinetics?
Police Stop Heavy Drinkers
Phenytoin
Salicyclates
Heparin
Alcohol
Which drugs are affected by acetylator status?
SHIP’D
Sulphasalazine Hydralazine Isoniazid Procainamide Dapsone
What interacts with macrolides?
Statins -> increase risk of myopathy/rhabdomyolysis
Amiodarone -> increases QT risk
Drugs causing urinary retention?
Nice TOAD NSAIDs TCAs Opioids Anticholinergics Disopyramide
What is the general action of heparins?
Anti-thrombin 3
How to monitor standard heparins and LMWH?
Heparins -> APTT
LMWH -> Anti-factor Xa
What is the MOA of HIT?
Plts release platelet factor 4
Binds to heparin
Which bind to IgGs forming an immune complex
These are recognised by the FC portion of platelets and leads to both thrombosis and thrombocytopaenia
UKMEC3 (dis>adv) for COCP
>35yrs and smoking <15/day BMI >35 FH of first degree relative with VTE <45yrs Controlled HTN Immobility BRCA1 or 2 positive Current GB disease
UKMEC4 (contraindications) for COCP
>35yrs and smoking >15/day BMI >40 Migraine with aura Hx VTE/stroke/IHD Breastfeeding <6wks post-partum (recent change from 6m to 6w) Uncontrolled HTN Current breast Ca
COCP risk and protective factors?
RISK: IHD, VTE, stroke, breast + cervical Ca
PROTECTIVE: Colorectal + ovarian + endometrial Ca, also PID
