Passmedicine Med Finals Pharmacology Flashcards
What effect can Amiodarone have on the thyroid gland?
It can cause hypothyroidism and thyrotoxicosis.
What are the treatment options for thyrotoxicosis?
- Thionamides (carbimazole, PTU, methimazole)
- Radioiodine
- Surgery
What is the Wolff-Chaikoff effect?
It’s an autoregulatory phenomenon that inhibits organification (thyroglobulin iodination), the formation of thyroid hormones and release into the bloodstream secondary to the ingestion of a large amount of iodine.
How does Amiodarone induce hypothyroidism?
The high iodine context of amiodarone causes a Wolff-Chaikoff effect.
How can Amiodarone induce thyrotoxicosis?
- AIT type 1 involves excess iodine-induced thyroid hormone synthesis, with a goitre present. Carbimazole should be used to treat.
- AIT type 2 involves destructive thyroiditis with an absent goitre. Corticosteroids are used to treat.
What is the brand name for Sildenafil?
Viagra
What are contraindicated in Viagra use?
- Nicorandil (K+ activator with a nitrate component)
- Nitrates
- Recent stroke or MI (wait 6 months according to NICE)
What is the mechanism of action of sildenafil?
It is a phosphodiesterase type V inhibitor
What is sildenafil used for?
Impotence
What are the side-effects of sildenafil?
Blue discolouration of vision, nasal congestion, flushing, GI side-effects and headache.
What medication is used first line in heroin/opioid detoxification?
- Methadone (agonist with less harmful effect)
- Buprenorphine (partial agonist with less harmful effect)
These are both synthetic opioids
What are some features of opioid misuse?
- Rhinorrhoea (runny nose)
- Needle track marks
- Pinpoint pupils
- Drowsiness
- Watery eyes
- Yawning
(Runny nose, runny eyes, drowsiness and yawning, pinpoint pupils and needle track marks)
What are some complications of opioid misuse?
- viral infection secondary to needle sharing (Hep B & C, HIV)
- bacterial infection secondary to injection (infective endocarditis, septic arthritis, septicaemia, necrotising fasciitis)
- VTE
- Respiratory depression and death
What is the emergency management of opioid overdose?
IV or IM naloxone
What drugs are used to treat urinary incontinence?
- Oxybutynin (anticholinergic)
2. Tolterodine
What is loperamide?
It is an opiate agonist used to reduce colonic motility in constipation.
What drug is used to reduce prostatic volume in BPH?
Finasteride (a 5-a-reductase inhibitor)
What drug is used to treat urinary retention?
- Tamsulosin (relaxes detrusor)
2. Finasteride (BPH)
What drugs are used for motion sickness?
Hyoscine (transdermal patch) > cyclizine (non-sedating anti-H1) > promethazine (sedating anti-H1)
What is cocaine derived from?
Alkaloid derived from coco plant
What is the mechanism of action of cocaine?
Blocks the uptake of dopamine, noradrenaline and serotonin.
What are some cardiovascular effects of cocaine?
- MI
- tachycardia and bradycardia
- hypertension
- QRS widening and QT prolongation
- aortic dissection
What are some neurological effects of cocaine?
- seizures
- mydriasis
- hypertonia
- hyperreflexia
What are some psychiatric effects of cocaine?
- agitation
- psychosis
- hallucinations
Are there any abdominal signs with cocaine use?
Ischaemic colitis can follow cocaine ingestion and should be considered if patients complain of abdominal pain or rectal bleeding.
How do you manage cocaine toxicity?
- First line = benzodiazipines
- chest pain = benzo + GTN with possible PCI if MI
- hypertension = benzo + sodium nitroprusside
If ALT and AST are elevated (transaminitis) in the 10,000s, what is the diagnosis likely to be?
Paracetamol overdose
What would the LFT look like with hepatitis A & B?
AST and ALT elevation but not as big as paracetamol overdose.
What does alcoholism look like in LFT?
AST > ALT, chronic alcoholism is reduced albumin and protein levels due to reduced protein synthesis.
What is the management of paracetamol overdose?
- Acetylcysteine (Activated charcoal if ingested <1 hour ago)
- Liver transplantation
What is the criteria for liver transplantation?
Arterial pH<7.3 24 hours after ingestion or creatinine > 300, prothrombin time > 100s or grade3/4 encephalopathy
What is a staggered paracetamol overdose?
If all the paracetamol tablets were not taken within 1 hour
How do you treat salicylate poisoning?
Haemodialysis
How do you treat Benzodiazepine overdose?
Flumazenil
How do you manage warfarin overdose?
Vitamin K and prothrombin
How do you manage heparin overdose?
Protamine sulfate
How do you treat b-blocker overdose?
Atropine if bradycardic. If resistant, Glucagon!
How do you treat carbon monoxide poisoning?
100% oxygen, hyperbaric oxygen.
What is the treatment of cyanide toxicity?
Hydroxocobalamin with amyl nitrate, sodium nitrate and sodium theosulfate
How do you manage organophosphate insecticide poisoning?
Atropine
Why could statins result in muscle pain?
They pose a risk of rhabdomyolysis which would increase creatine kinase levels x5
Which calcium channel blocker can precipitate pulmonary oedema in someone with known heart failure?
Verapamil
What is a major side effect of Ca2+ channel blockers?
Ankle swelling
Which Ca2+ channel blockers can you give to patients in heart failure?
Dihydropiridine - they work on peripheral vasculature so don’t affect the heart
What are the two types of heparin?
- Unfractionated normal heparin
2. Low molecular weight heparin
What factors does unfractionated heparin inhibit?
- thrombin
2. factors 5a, 9a, 11a and 12a
What factor does low molecular weight heparin affect?
Anti-thrombin 3 activity is increased on factor 5a
What are the main side effects of unfractionated heparin (and to a lesser extent, LMW)
- bleeding
- heparin-induced thrombocytopaenia (HIT)
- osteoporosis
What test is used to monitor unfractionated heparin?
APTT
What can heparin do to potassium levels?
Hyperkalaemia
Name some anti-emetics
- cyclizine
- metoclopramide
- ondensantron
- chlorpromazine
- prochlorperazine
- promethazine
What anti-epileptic drugs are safe to prescribe in the first trimester of pregnancy?
- lamotrigine
- carbamazepine
What anti-thyroid drug is safe to prescribe in the first trimester of pregnancy?
PTU
What can precipitate lithium toxicity?
- dehydration
- renal failure
- ACE inhibitors
- diuretics (BFT)
- metronidazole
What are some features of lithium toxicity?
- coarse tremor
- hyperreflexia
- acute confusion
- seizure
- coma
How do you manage lithium toxicity?
Normal saline (and haemodialysis if severe) and there is limited evidence for sodium bicarbonate.
What are the recommended ALS doses for adrenaline?
Anaphylaxis = 0.5ml 1:1000 IM (o.5mg contained)
Cardiac arrest = 1ml 1:1000 IV (1mg of adrenaline contained)
How do you treat accidental injection?
Local infiltration of phentolamine
What are the most likely side effects seen with bendroflumethiazide?
Postural hypotension and hypokalaemia
What is a common side effect of clopidogrel?
GI symptoms
What are the common side effects of ACE inhibitors?
Hypotension, renal dysfunction and a dry cough
What is the MOA of finasteride?
5a-reductase inhibitor
When can you use finasteride?
- BPH
2. Male-pattern baldness
What are some side effects of finasteride?
- impotence
- decreased libido
- ejaculation disorders
- gynaecomastia and breast tenderness
What does finasteride do to serum prostate specific antigen?
It decreases it
What is a common side effect of metformin?
Diarrhoea
What, other than DMII, is metformin used for?
PCOS
How common is it for metformin to cause lactic acidosis?
Rare
What are characteristic features of digoxin toxicity?
Xanthopsia (yellow-tinted vision)
What classically precipitates digoxin toxicity?
Hypokalaemia
How do you manage digoxin toxicity?
Digibind
Correct arrhythmia
Monitor potassium
What is diclofenac?
NSAID used for arthritis
What is contra-indicated for diclofenac?
Cardiovascular disease
What are common side effects of Isoniazid?
Peripheral neuropathy, psychosis and hepatotoxicity
What are common side effects of rifampicin?
Orange bodily fluids, rash, hepatotoxicity
What are common side effects of pyrazinamide?
Arthralgia, gout, hepatotoxicity and nausea
What are common side effects of ethambutol?
Optic neuritis and a rash
What are some examples of drugs which induce P450 in the liver and thus reduce the effectiveness of contraceptives?
Anti-epileptics: phenytoin, carbamazepine
Barbiturates: phenobarbitone
Rifampicin
St John’s Wort
Chronic alcohol intake
Griseofulvin (fungal infection)
Smoking (affects CYP1A2 which is why smokers require more aminophylline)
Tendon damage (e.g. Achilles rupture) is a well known complication of what class of drug?
Quinolones such as cirpo/levofloxacin
Ciclosporin is associated with what side effect?
Hepatotoxicity (and nephron)… Remember… everything is increased! K+, BP, gums, hair, tremor!!!
What is first line in diabetic neuropathic pain?
Duloxetine
What is the first line management of phantom limb pain (neuropathic pain)?
Pregabalin or amitriptyline (orthostatic hypotension is a side effect of amitryptiline)
What is Mefloquine?
Malaria prophylaxis and treatment (consider history of anxiety and depression before administering)
What is the yellow card scheme?
The way to report adverse reactions to medications. Collated by the Medicines and Healthcare products Regulatory Agency (MHRA)
What are the common side effects of Nitrates?
Postural hypotension, headaches and tachycardia
What are the common side effects of b-blockers?
Bronchospasms (asthmatics), fatigue, cold extremities and sleep disturbances
What does verapamil commonly cause (side-effect wise)?
Constipation
What drug commonly causes anal ulceration?
Nicorandil
Describe the drugs that affect the serotonin system.
Agonists include:
- sumatriptain which is a HT1 receptor agonist used to treat acute migraine
- ergotamine is a partial agonist of HT1
Antagonists:
- pizotifen (migraine prophylaxis)
- cyproheptadine (diarrhoea in carcinoid syndrome)
- ondansetron in anti-emesis
What T-score is required to be diagnosed with osteoporosis?
T score of
What is first line for the treatment of osteoporosis?
Alendronate
What are examples of other bisphosphonates if alendronate isn’t well tolerated?
- Risendronate
2. Etidronate
What is a common side effect for patients to experience on alendronate, and is reason for medication review?
GI symptoms
What drugs are available if a patient can’t tolerate bisphosphonates?
- Raloxifene
2. Strontium ranelate
What are the symptoms of digoxin toxicity?
- nausea
- vomiting
- confusion
- yellow-green tinted vision
- arrhythmias such as bradycardia and AV block
- gynaecomastia
What syndrome can St. John’s Wart cause?
Serotonin syndrome
Give some examples of stimulants.
Amphetamines, methamphetamines, MDMA (ecstacy), cocaine, nicotine and caffeine.
Give some examples of depressants.
Alcohol, benzodiazepines, opioids, cannabis.
Give some examples of hallucinogens.
Psilocybin, LSD, phencyclidine, ketamine.
Give some examples of macrolides.
Erythromycin, chlarithromycin, clindamycin
Give some examples of aminoglycosides.
Gentamycin, neomycin, streptomycin
Give some examples of B-lactams.
Penicillins, ampicillin, amoxicillin, cephalosporins
Give some examples of sulphonamides.
Tripethoprim and sulfamethoxazole
Give examples of quinolones.
Floxacins (Cipro/levo/nor)
Give an example of a tetracycline.
Doxycyclin
When would you monitor lithium levels?
Immediately before dose
When would you monitor digoxin levels?
At least 6 hours post-dose
When would you monitor ciclosporin the immunosuppressant?
Immediately before dose
When would you monitor phenytoin?
Not usually unless fear of OD
What is dantrolene?
A drug used to relax muscles in muscle spasm. It may also be used to manage hyperthermia in ecstacy poisoning if simple measures fail.
What are some clinical features of ecstacy poisoning?
It is a stimulant so…
- tachycardia, hypertension
- hyperthermia, hyponatraemia
- agitation, anxiety, ataxia etc…
- rhabdomyolysis
What is the management of ecstacy poisoning?
Supportive, dantrolene may be used for hyperthermia if simple measures fail
In cardiac bypass, a thrombogenic procedure, a large dose of what drug is administered to ensure no clots form?
Heparin
After successful CABG, what drug needs to be administered following coming off cardiac bypass?
Protamine sulphate (reverses heparin).
After successful CABG, what drug needs to be administered following coming off cardiac bypass?
Protamine sulphate (reverses heparin)
What are some common features of carbon monoxide poisoning?
Headache, nausea, vomiting, confusion, vertigo.
What % of carbon monoxide in the blood results in symptoms?
10-30%
What % of carbon monoxide is present in the blood of someone who is severely toxic?
> 30%
What is the % of carboxyhaemoglobin in the blood of a smoker and non-smoker (respectively)?
<10% and <3%
What are some typical side effects of certain antibiotics?
Amoxicillin - rash with infective mononucleosis
Co-amoxiclav & flucloxacillin - cholestasis
Erythromycin - GI upset and QT prolongation
Ciprofloxacin - tendonitis and seizure threshold lowering
Metronidazole - rx with alcohol Doxycycline - photosensitivity
Trimethoprim - rashes, pruritus, suppression of haematopoiesis
Which TB drug inhibits the P450 system?
Isoniazid
Name some other drugs which are P450 inhibitors.
- antibiotics
- amiodarone
- allopurinol
- acute alcohol intake
- omeprazole
- SSRIs
- sodium valproate
What are some side effects of Metformin?
Diarrhoea
Decreased B12 absorption
Lactic acidosis in px with tissue hypoxia
What are some contra-indications of metformin?
- CKD
- lactic acidosis
- alcohol
- iodine X-rays
What drugs must be avoided in renal failure?
- antibiotics such as tetracycline and nitrofurantoin
- NSAIDs
- lithium
- metformin
What drugs are relatively safe for the kidneys?
- antibiotics such as erythromycin and rifampicin
- diazepam
- warfarin
What are alpha blockers used for?
- BPH (e.g. tamsulosin)
2. hypertension
What are the two types of K+-sparing diuretics and give examples of each.
- Aldosterone antagonist: spironolactone or eplenerone
2. Epithelial sodium channel blocker: Amiloride
When can potassium sparing diuretics be used?
- Ascites
- Heart failure
- Conn’s syndrome
- Nephrotic syndrome
How can Amiodarone affect the eyes?
Corneal opacities and optic neuritis
If a patient presents with bilateral ankle swelling secondary to Ca2+ channel blockers, how should this be managed?
By swapping Amlodopine for a second-line anti-hypertensive such as Indapamide.
What factor is an absolute contraindication to the use of regional anaesthesia?
Concurrent administration of therapeutic dose of warfarin (due to the risk of bleeding and the severity of a haematoma within the CNS).
When does warfarin have to be stopped during an operation?
5 days pre-op and substituted with a LMW heparin.
What drugs can cause optic neuritis?
Amiodarone, ethambutol and metronidazole
What drugs can cause corneal opacities?
Amiodarone and indomethacin
What is the main monitoring parameter for statins once prescribed?
LFTs!!! At baseline, 3 months and 12 months!
What is mesalazine?
A drug used to treat IBD e.g. ulcerative colitis
What is the most useful prognostic marker for paracetamol overdose?
Prothrombin time
The concomitant use of both a nitrate and a phosphodiesterase inhibitor can lead to what?
Significant hypotension and precipitation of MI
Tamoxifen is an oestrogen receptor antagonist in breast tissue. It can however act as an agonist in other tissues. Which cancer has an increased risk of being developed with tamoxifen use?
Endometrial cancer
What factors increase the likelihood of developing liver failure in someone who has a paracetamol overdose?
- chronic alcohol
- anorexia
- P450 inducers
What is a common side effect of metformin?
Diarrhoea
What is a common side effect of sulfonylureas?
Hypoglycaemia
What is a common side effect of glitazones?
Weight gain (HF in pio)
What is an oculogyric crisis?
A dystonic reaction to certain drugs or medical conditions. Causes include phenothiazines, metoclopramide, parkinsons…
What drugs should be stopped in someone with kidney failure?
- NSAIDs
- Metformin
- Tetracycline
- Lithium
What drugs are OK in patients with kidney failure?
- Warfarin
- Diazepam
- Erythromycin
What drugs can cause pulmonary fibrosis?
Amiodarone, methotrexate, bromocriptine (ergot derivatives) and cytotoxic agents like bleomycin
What are some side effects of macrolides?
GI effects, P450 inhibitor, cholestatic jaundice
What is the treatment of neuropathic pain?
First line: pregabalin or amitriptyline
Second line: combined
Third line: Tramadol
Diabetic neurophaty: duloxetine
What is the typical presentation of someone who has had a TCA OD?
- dilated pupils
- dry skin
- urinary retention
- confusion etc
(Get anti-sludge as has an effect on blocking cholinergic receptors too) - BIG ONE IS DIVERGENT PUPILS!
How do you treat TCA overdose?
fluids and IV sodium bicarbonate
Hyperreflexia is a classic symptom of what?
Serotonin syndrome (no dry skin)
What is classically seen in an aspirin overdose on ABG?
Initially a respiratory alkalosis due to increased respiratory effort. Following, a metabolic acidosis alongside due directly to the salicylic acid.
What is the treatment of aspirin overdose?
ACB, charcoal. Urinary alkalinisation with sodium bicarb IV. Haemodialysis.
What is the typical presentation of someone with aspirin OD?
Anxiety. Tinnitus. Diaphoresis.
How do you treat acute withdrawal of alcohol?
Benzodiazepines