Student Formulary Drugs Flashcards
When would you prescribe Activated Charcoal
Paracetamol overdose or aspirin (salicylate) overdose- if <1hr since ingestion
What would you treat a paracetamol overdose with?
- Activated charcoal (if less than 1hr since taking overdose)
- N-acetylcysteine if 4hr paracetamol level is above treatment line or if below normal treatment line but considered high risk
(High risk = on p450 inducer medications (phenytoin, carbamazepine, rifampicin, St Johns wart), alcoholic, HIV+ or malnourished (glutathione depletion))
What would you treat an aspirin overdose with?
- Activated charcoal if less than 1hr since overdose
- Alkalinise urine using sodium bicarbonate +/- potassium chloride - often no longer used
- Haemodialysis - 1st line if pulmonary oedema /severe poisoning
On an ABG what would an aspirin overdose look like?
Metabolic acidosis with respiratory alkalosis for compensation pH <7.35 PaO2 high PaCO2 low Bicarb low BE low
Patient arrives in A&E breathing extremely rapidly. You do an ABG. These are the results: pH 7.1 PaO2 12 PaCO2 2.65 Bicarb 4.7 BE -29.2 What do you suspect?
Metabolic acidosis with respiratory alkalosis for compensation. Potentially a salicylate overdose
Docusate sodium - MOA?
When is it contraindicated
Stimulate laxative - increases intestinal motility
CI: bowel obstruction
What are examples of stimulant laxatives?
When are they CI?
Docusate sodium Glycerin (PR) Senna Picosulfate CI: bowel obstruction
What is a glycerin enema used for? MOA? CI?
constipation
stimulant laxative
CI: bowel obstruction
Senna
stimulant laxative
CI: bowel obstruction
Picosulfate
stimulant laxative
CI: bowel obstruction
Bran. MOA? SE? CI?
Bulking agent - increase faecal mass and therefore increase peristalsis
SE: bloating
CI: bowel obstruction
Ispaghula. MOA?SE? CI?
Bulking agent - increase faecal mass and therefore increase peristalsis
SE: bloating
CI: bowel obstruction
Examples of bulking agents used in constipation?
Bran
Ispaghula
What are examples of osmotic laxatives? When are they contraindicated?
Lactulose Macrogel Phosphates Mg Salts CI: bowel obstruction
What is lactulose? What is it used for?
Osmotic laxative - increases water content of stools. Used in: - constipation - hepatic encephalopathy (CI: bowel obstruction)
What is an example of a stool softener?
liquid paraffin
What is liquid paraffin?
What are its side effects
stool softener. used in constipation.
SE: decreased absorption of ADEK vitamins (Fat soluble)
Granulomatous reactions
What is a phosphate enema used for? How does it work?
Constipation. It is an osmotic laxative - increasing the water content of the stool
What is gaviscon and when is it used?
Gaviscon = alginate
Used in GORD
Decreases reflux by increasing the viscosity of the stomach contents. It forms a raft on top of stomach contents
Can be bought OTC
What are examples of antacids and when are they used?
Mg Trisilicate
Al hydroxide
They are used in dyspepsia, GORD and PUD. They neutralise gastric acid.
Take when symptoms occur / are expected - PRN
They can interfere with drug absorption
Constipation is a side effect of which antacid
Al hydroxide
Diarrhoea is a side effect of which antacid
Mg trisilicate
Movicol - what is it ? How does it work? When should you not give it?
Osmotic laxative + potassium chloride, sodium chloride and sodium bicarbonate. Comes in a sachet that you mix with water and drink.
Works by increasing the water content in the stool.
Should not be given if you suspect bowel obstruction - so if patient is distended, constipated, severe pain, vomiting etc..
Omeprazole, lanzoprazole, pantoprazole. How do they work?
Proton pump inhibitors Activated in acidic pH Irreversibly inhibit H+/K+ ATPase More effective than H2 antagonists such as ranitidine May mask symptoms of gastric cancer
Side effects of PPIs
Headache
GI disturbance
What do PPIs interact with
p450 inhibitors e.g. many antibiotics, isoniazid, cimetidine, sodium valproate, chloramphenicol
Ranitidine, cimetidine. MOA?
H2 receptor antagonist
Decrease gastric parietal cell H+ secretion
Cimetidine. SE? Interactions?
GI disturbance
Interact with p450 inhibitors e.g. isoniazid, chloramphenicol, sodium valproate
May mask symptoms of gastric cancer
What is often given with NSAIDs to prevent PUD?
Misoprostol - prostaglandin analogue
Acts on parietal cells to decrease H+ secretion.
Common SE : diarrhoea
ACEI - ramipril, lisinopril, enalapril. What are they used for?
HF HTN Post-MI Angina Diabetic nephropathy
What are the SEs of ACEI
hypotension renal failure increased potassium Dry cough: 10-20% - due to increased bradykinin Angioedema (~0.1%)
When are ACEI contraindicated?
Bilateral renal failure
Angioedema/hypersensitivity to ACEI
Salt substitutes (containing K+)
Pregnancy
What does ramipril interact with?
Increased risk of RF in patients on NSAIDs
Diuretics, TCAs and antipsychotics - risk of hypotension
Caution with drugs that increase K+ e.g. spironolactone
What needs to be monitored on ACEI?
U&Es - an increase in creatinine >30% -stop
titrate dose
avoid in young women likely to become pregnant - consider beta-blocker.
decrease dose in renal failure
What is the MOA of losartan
Angiotensin receptor blocker - do not inhibit bradykinin breakdown so no cough
What are the SE of ARBs
Same as ACEI: Hypotension Increased K+ Renal failure Angioedema (~0.1%)
Contraindications of ARBs
Caution in RF
Do not use in pregnancy
Interactions of losartan?
Hypotension- risk with diuretics, TCAs and antipsychotics
Increased risk of renal failure with NSAIDs
Caution when using in patients on drugs that increase K+ e.g. spironolactone
Patient has recently been started on a new drug and begins to find breathing more difficult and swelling of his tongue. What would you prescribe?
High flow oxygen through a non-rebreathe mask
Adrenaline 0.5ml of 1:1000
Chloramphenamine 10mg IV
Hydrocortisone 200mg IV
Nebulisers: salbutamol 5mg and ipratropium 0.5mg
Bendroflumethiazide - MOA?
Thiazide diuretics - acts in distal convoluting tubule.
Inhibits NaCl transporter and therefore increases excretion of NaCl
Name thiazide diuretics
Bendroflumethiazide
Metolazone
Chlortalidone
SEs of thiazide diuretics e.g. bendroflumethiazide
low K+ low Na+ high calcium high urate (gout) (as compete for the same transporter) postural hypotension increased glucose and DM
Contraindications to thiazide diuretics
Gout
Refractory hypokalaemia
Severe renal failure
Interactions of thiazides
increase toxicity of digoxin and lithium
What are nifedipine and amlodipine? When are they used?
Dihydropyridine Calcium channel blockers
Used in treatment of HTN, angina, prinzmetals angina and raynauds
How does nifedipine work?
Blockers of calcium channels mainly in arterial smooth muscle Cause vasodilatation (including of coronary arteries) (particularly of pre-capillary arterioles) Decrease total peripheral resistance so increase sympathetic tone and therefore increase HR
What are side effects of amlodipine and nifedipine
flushing headache ankle oedema (amlodipine) dizziness hypotension gingival hypertrophy (nifedipine)
Contraindications to dihydropyridine CCBs?
cardiogenic shock
unstable angina
significant AS
within 1month of MI
What do dihydropyridine CCBs interact with?
alpha / beta blockers - > hypotension
grapefruit juice increases dose (p450 inhibitor)
rifampicin, CMZ and phenytoin decrease dose (p450 inducers)
nifedipine only - increases function of digoxin
What are diltiazem and verapamil
Non-dihydropyridine CCBs
How does diltiazem work?
Block calcium channels
Mainly cardiac effect
-ve inotrope
(verapamil also slows conduction at SA and AV node)
some activity at arterial SM (<dihydropyridines)
What are SEs of verapamil and diltiazem
headache flushing ankle oedema AV block HF Hypotension constipation gynacomastia (verapamil)
When are verapamil and diltiazem contraindicated?
HF (2nd/3rd degree AV block)
What do verapamil and dilitiazem interact with
Beta blockers - risk of AV block, HF and asystole
increase function of digoxin
function of verapamil increased by grapefruit juice or macrocodes (p450 inhibitors)
simvastatin - increased risk of myopathy
when are non-dihydropyridines used?
Angina,
HTN
arrhythmias (verapamil)
Clopidogrel
irreversible adenosine receptor antagonist
inhibits ADP-induced fibrinogen binding to GPIIb/IIIa
SEs clopidogrel
bleeding GI upset dyspepsia / PUD TTP (rare) blood dyscrasias (rare)
When should clopidogrel not be used?
With warfarin
Amiodarone. MOA?
Class III - K+ channel blocker
Increases refractory period - increases QT interval
When is amiodarone used?
Ventricular and supra ventricular tachycardias and WPW syndrome.
BUT can cause arrhythmias (torsades de points)
Aspirin. MOA?
Irreversible non selective COX inhibitor
Prevents formation of thromboxane A2 and therefore decreases platelet adhesion and aggregation.
Relatively platelet specific at low doses 75mg-150mg
Side effects of aspirin?
Gastritis
Gastric ulceration
Bleeding
Bronchospasm
Rarer:
renal failure
gout
ototoxic in overdose: tinnitis
Contraindications to aspirin
<10ml/min
Pregnancy
Caution in asthma & uncontrolled hypertension
What does aspirin interact with?
Other anti-coagulants and anti-platelets -> bleeding
Increases function of sulphonylureas and methotrexate
When should aspirin be stopped before a surgery which may involve significant bleeding?
7 days
Digoxin. MOA?
Cardiac glycoside - bind to Na/K ATPase & cause build up of intracellular calcium
Anti-arrythmic agent
Increase contractility of myocytes
When is digoxin prescribed?
AF/flutter
SVT
(HF)
What are SEs of digoxin
Due to Toxicity:
Arrhythmias
Nausea
Xanthopsia (yellow tint)
Chronic SE:
gynaecomastia
“reverse tick” ECG - not a sign of toxicity
Contraindications to taking digoxin
Complete heart block
VF/VT
HOCM
SVTs secondary to WPW
What does digoxin interact with?
Digoxin function increased by:
CCB (esp verapamil)
Diuretics (loop / thiazide due to decreased K)
Amiodarone (halve digoxin dose)
Decreased digoxin absorption:
antacids
cholestyramine
Side effects of amiodarone
EYE - corneal microdeposits
Thyroid - hyper/hypo
Lung - pulmonary fibrosis
GI/Liver - increased LFTs, N/V
Neuro - peripheral neuropathy
Skin - photosensitivity, blue/grey discolouration, phlebitis (give centrally)
Side effects of methotrexate
Myelosuppression
Liver cirrhosis
Pneumonitis
Side effects of sulfasalazine
Rashes
Oligospermia (low sperm count)
Heinz body anaemia
stevens- Johnson syndrome
Side effects of leflunomide
Liver impairment
Interstitial lung disease
Hypertension
What is methotrexate ?
Antifolate (Inhibits dihydrofolate reductase and thymidylate synthesis)
Commonly used in rheumatoid arthritis
What is leflunomide
Dmard
Pyramiding synthesis inhibitor
What is hydroxychloroquine? What are it’s side effects?
Antimalarial (used in RA)
Retinopathy
Corneal deposits
What are the side effects of prednisolone?
Cushingoid (centripetal weight gain, moon face, buffalo hump) Osteoporosis Decreased glucose tolerance Hypertension Cataracts
What is a side effect of gold
Proteinuria
Side effects of penicillamine
Proteinuria
Exacerbation of myasthenia gravis
Ethanercept - TNF inhibitor
Side effects?
Demyelination
Reactivation of Tb
Infliximab (TNF mab) side effects?
Reactivation of Tb
Adalimumab (TNF mab) side effects
Reactivation of Tb
Rituximab - anti cd20 side effect?
Infusion reactions common
Dipyridamole. MOA?
Class I anti-arrhythmic
Phosphodiesterase inhibitor - increased cAMP inhibits platelet aggregation
Thromboxane A2 synthetase inhibitor
SE of dipyridamole?
Headache
What does dipyridamole interact with?
enhances effects of adenosine
When is dipyridamole used?
May be used with aspirin in secondary prevention of stroke
When is dipyridamole contraindicated?
Myasthenia gravis
How does bumetanide work?
Loop diuretic (like furosemide)
Inhibits Na/K/Cl transporter in ascending limb of loop of Henle
Increases NaCl excretion
SEs of loop diuretics?
Low Na Low K Low Ca Low Mg High Urate Postural hypotension Tinnitus / deafness (rare)
(monitor U&Es)
(May add K+ sparing diuretic to decrease K loss)
What are contraindications to taking loop diuretics?
Refractory hypokalaemia
Anuric renal failure
What do loop diuretics interact with
Increase toxicity of:
- digoxin (due to decreased K)
- NSAIDs
- Gentamicin
- Li
Nicorandil. MOA?
K(ATP) channel activator & nitrate component
Arterial and venous dilator
Used as an anti-anginal in uncontrolled angina
SEs Nicorandil
Flushing
Headache
Dizziness
GI ulcers (rare)
When is nicorandil contraindicated
Cardiogenic shock
What does nicorandil interact with
Sildenafil (decreases BP)
GTN. MOA?
NO donor with rapid onset and short duration (30 mins)
Used for angina
cause release of nitric oxide in smooth muscle, increasing cGMP which leads to a fall in intracellular calcium levels
in angina they both dilate the coronary arteries and also reduce venous return which in turn reduces left ventricular work, reducing myocardial oxygen demand
Isosorbide mononitrate -MOA?
Long acting nitrate - used for angina
Is an active metabolite of ISDN
Mononitrate avoids unpredictable first pass metabolism of denitrate
Tolerance develops quickly: need 8h drug free period (usually at night)
SEs of nitrates?
Hypotension
Headache
syncope
dizziness
flushing
reflex tachycardia
CIs to nitrates
Atrial stenosis and Mitral stenosis Hypotension Constrictive pericarditis Tamponade HOCM Low Hb Glaucoma (closed) Hypovolaemia Increased ICP
What do nitrates interact with?
sildenafil, tadakafil and vardenafil -> low BP
Decreased function of heparins if given IV
prothrombin complex concentrate- MOA
combination of blood clotting factors II, VII, IX and X, as well as protein C and S
prepared from fresh-frozen human blood plasma
used to reverse the effects of oral anticoagulation therapy (warfarin) when bleeding occurs
when INR >8
also used in deficiencies of clotting factors e.g. congenital, haemophilia, or liver disease
Spironolactone / eplerenone. MOA?
Aldosterone receptor antagonist
K+ sparing diuretic
Increase Na excretion
Decrease H and K excretion
Side effects of spironolactone
Increased K
Gynacomastia
Contraindications to spironolactone
increased K
Pregnancy
Addisons
Spironolactone interacts with which drugs?
Digoxin and lithium - increases their toxicity
Amiloride. MOA?
Typically used in combination with K+ wasting diuretics.
Block Na channels in collecting tubules
- increase Na excretion
- decrease K and H excretion
SE: include increased K+ and GI upset
Statins. MOA?
Lipid lowering therapy HMG-CoA reductase inhibitors - block the rate limiting step in cholesterol synthesis - decrease hepatocyte cholesterol - increase hepatic LDL receptors - decrease LDL cholesterol - increase HDL - decrease triglycerides (mild)
SEs of statins
Myositis
- stop if CK 5x ULN
- can cause rhabdomyolysis & ATN
Deranged LFTs
GI upset
Contraindications to statins
Pregnancy ( contraception needed during use and for 1 month after)
L
When are statins indicated
any known CVD
DM (age >40)
10yr CVD risk >20%
AIM: TC<4mM
What do statins interact with
Increased risk of myositis with:
- fibrates
- macrolides
- azoles
- grapefruit juice
- protease inhibitors
- ciclosporin
- nicotinic acid
What time of day should statins be taken? What should be monitored on statins?
LFTs and CK
Take nocturnally as increased cholesterol synthesis overnight
What are examples of alpha receptor blockers?
Alfuzosin
Doxazosin (alpha1)
Tamluzosin
(phenoxybenzamine and phentolamine are non selective alpha receptor blockers)
How does doxazocin work?
alpha 1 receptor blocker
systemic vasodilatation - antihypertensive
relaxation of internal urethral sphincter
Side effects of alpha blockers
postural hypotension dizziness headache urinary incontinence (esp women) blurred vision
What do alpha blockers interact with?
diuretics
Beta blockers
CCBs
Phentolamine - what is it & what is it used for
Non selective alpha receptor blocker
SHort acting - used to control BP in phaeochromocytoma
Phenoxybenzamine. MOA. USE?
Alpha receptor blocker
Long acting
Used to maintain alpha blockade in phaeochromocytoma once BP is controlled
When are doxazosin and tamulosin used? MOA
Alpha 1 receptor blockers
used in treatment of benign prostatic hypertrophy
Name cardioselective beta blockers
bisoprolol
atenolol
metoprolol
name non-selective beta blockers
propranolol
carvedilol
sotalol
labetolol
How do beta blockers work?
act via B1 receptors to decrease CO
- decrease HR
- decrease contractility
- small decrease in BP: central effect due to decreased renin
Effects:
increase diastolic perfusion
decrease o2 demand
decrease afterload
Side effects of beta blockers
Bronchospasm
Peripheral vasoconstriction - cold extremities - worsens Raynauds and peripheral vascular disease
Lethargy / fatigue
Nightmares
Metabolic - decrease HDL, increase triglycerides, increase risk of new onset DM
What do beta blockers interact with
Verapamil and diltiazem - risk of AV block and decreased HR
Enhanced decreased BP with other anti-HTN drugs
Block symptoms of decreased glucose with insulin
When is amiodarone prescribed
SVT
AF/flutter
pre-excited AF
ventricular arrhythmias (incl VF)
When is amiodarone contraindicated
Thyroid disease
Sinus bradycardia
increased QT interval - causes torsades de pointes
What does amiodarone interact with
Beta blockers and CCB - increase risk of heart block
Increased levels of digoxin, warfarin and phenytoin
Increase risk of ventricular arrhythmias with class III/IIa antiarrhythmics, TCAs, antipsychotics, eryhtromycin
What is ipratropium. what does it do?
Short acting muscarinic antagonist
3-6hrs
bronchodilation
decreases mucus secretion
SE: dry mouth
Caution: with close angle glaucoma & prostatic hypertrophy
What is tiotropium?
Long acting muscarinic antagonist
aka Spiriva
bronchodilatation
decreased mucus secretion
SE: dry mouth
Caution with closed angle glaucoma and prostatic hypertrophy
Salbutamol
short acting beta agonist
act on bronchial B2 receptors
SM relaxation
decrease mucus secretion
SE of salbutamol
Tachycardia
Tremor
low K+ in high doses with corticosteroids, loop/thiazide diuretics or theophylline
Salmeterol
Long acting beta agonist
12-18 hrs
Chloramphenamine
Antihistamine
Piriton
H1 receptor inverse agonist
SE of chloramphenamine
Hypotension
arrhythmia (increase QT interval)
Drowsiness
Anti-AChM
When is chloramphenamine contraindicated
severe hepatic disease
Use with caution in:
Long QT
BPH
Closed angle glaucoma
Beclometasone
Inhaled corticosteroids
act over weeks to decrease inflammation
decrease cytokine production
decrease prostaglandin / leukotriene synthesis
decrease IgE secretion
decrease leukocytes recruitment
prevent long term decrease in lung function
SE of inhaled corticosteroids
oral candidiasis
high doses may cause typical steroids SEs
Budesonide
Pulmicort
Inhaled corticosteroids
act over weeks to decrease inflammation
decrease cytokine production
decrease prostaglandin / leukotriene synthesis
decrease IgE secretion
decrease leukocytes recruitment
prevent long term decrease in lung function
Fluticasone
Inhaled corticosteroids
act over weeks to decrease inflammation
decrease cytokine production
decrease prostaglandin / leukotriene synthesis
decrease IgE secretion
decrease leukocytes recruitment
prevent long term decrease in lung function
Symbicort
Budesonide (inhaled corticosteroid) and formoterol (long acting beta agonist)
Seretide
fluticasone (inhaled corticosteroid) + salmeterol (long acting beta agonist)
Nicotine replacement therapies
Nicotine patches, acuhalers, gum
Buproprion - decrease cravings (noradrenaline, dopamine reuptake inhibitor)
SE: increase risk of epileptic seizures if epileptic
What are the main SEs of metformin
GI side effects
lactic acidosis
What are the main SEs of glimepiride
Glimepiride is a sulphonylurea used in the treatment of diabetes.
SE: hypoglycaemic episodes increased appetite and weight gain SI ADH liver dysfunction (cholestatic) photosensitivity peripheral neuropathy
What are the SEs of pioglitazone
Pioglitazone is a glitazone used in the treatment of diabetes.
SE include: weight gain
fluid retention
liver dysfunction
fractures
What are examples of atypical antipsychotics?
Olanzapine
Clozapine
Quetiapine
Risperidone
What is quetiapine?
Atypical antipsychotic
Dopamine antagonists
What are the side effects of olanzapine?
weight gain
DM
sedation
What are the side effects of clozapine?
agranulocytosis
weight gain
DM
(atypical antipsychotic used in the treatement of refractory schizophrenia)
What are the side effects of quetiapine
atypical antipsychotic - dopamine antagonist
SE: sedation
What are the side effects of risperidone?
atypical antipsychotic - dopamine antagonist
SE: increased weight, increased prolactin
Lithium. SEs:
Mood stabiliser
SEs: polyuria and polydipsia nephrotoxic GI upset fine tremor hypothyroidism
TOXICITY: coarse tremor, cerebellar signs, AKI, hyper-reflexia, coma
Lithium interacts with?
NSAIDS, diuretics and ACEI/ARB increase the toxicity of lithium
What are examples of benzodiazepines?
chlordiazepoxide diazepam lorazepam midazolam temazepam
How do benzodiazepines work?
Promote GABA binding to GABAa receptors
SEs of chlordiazepoxide?
benzodiazepine SEs:
sedation
respiratory depression
withdrawal
Levels of benzodiazepines increased by:
Antipsychotics
Azoles
Macrolides
How would you treat a benzodiazepine overdose?
Flumazenil
What are examples of typical antipsychotics
chlorpromazine
haldol
sulpiride
zuclopenthixol
(dopamine antagonists)
Side effects of typical antipsychotics
sedation anti-AChM EPSEs - extrapyramidal side effects neuroleptic malignant syndrome Increase QT postural hypotension increased prolactin sexual dysfunction increased weight
Cocodamol. what is it?
Mix of paracetamol and codeine
Paracetamol = antipyretic & analgesic Codeine = weak opioid (via mu receptor)
Co-dydramol. what is it
Mix of dyhydrocodeine tartrate & paracetamol
Dyhydrocodeine = weak opioid
What are side effects of opioids?
CNS SEs: Resp depression sedation n/v euphoria meiosis anti-tussive dependence
Non-CNS constipation urinary retention pruritis bradycardia, hypotension
TREAT OVERDOSE WITH NALOXONE
decrease dose in renal impairment, hepatic impairment & elderly
Gabapentin SEs:
MOA unknown
sedation
cerebellar function
dizziness
peripheral oedema
What are examples of opioids
Strong opioids: morphine fentanyl pethidine diamorphine oxycodone buprenorphine
weak opioids
dihydrocodeine
tramadol
Examples of TCAs
Amitriptylline Nortroptyline lofepramine clomipramine imipramine doxepin
How does amitriptyline work
TCA
inhibit 5HT and NA uptake
SEs of TCAs?
alpha 1: postural hypotension, sedation
H1: drowsiness, weight gain
Anti-AChM
Arrhythmias - especially Heart block
What do tricyclics interact with?
MAOIs -> hypertension and CNS excitation
Levels increased by SSRIs
Increased risk of arrhythmias with amiodarone
Lower seizure threshold - decrease effect of anti-epileptics
increase function of antipsychotics
Contraindications to TCAs
Recent MI / arrythmia
Mania
Caution:
glaucoma
BPH
What drugs cause urticaria
Immune: penicillins, cephalosporins
Non-immune: contrast, opiates, NSAIDs
What drugs cause erythema nodosum
sulphonamides
penicillins
phenytoin
OCP
What drugs cause erythema multiforme
sulphonamides NSAIDs allopurinol phenytoin penicillin
what drugs cause photosensitivity reactions to the skin
amiodarone
thiazides
sulfonylureas
doxycycline
what drugs cause lupus like reactions to the skin
hydralazine
isoniazid
penicillamine
What drugs cause fixed eruptions to the skin
erythromycin
sulphonamides
Cyclizine. MOA
anti-emetic
H1 receptor antagonist
Contraindications to cyclizine
severe HF
MOAIs (can increase cyclizine’s anti-AchM function)
Indications for prescribing cyclizine?
Pnt on opioids
Vestibular
Examples of D2 receptors antagonists?
Metoclopramide
Prochlorperazine
Domperidone
Anti-emetics
Side effects of metoclopramide?
D2 receptor antagonist (like prochlorperazine and domperidone)
SEs: Extrapyramidal SEs (EPSEs) - dystonias, oculogyric crisis
Drowsiness
Rash
allergy
Increased prolactin
metoclopramine - interactions?
Increased risk of EPSEs with antipsychotics, TCAs and SSRIs
domperidone does not cross the BBB and therefore has less EPSEs than the others
Indications for prochlorperazine?
And other D2-receptor antagonists used as anti-emetics
GI causes - esp GORD Chemo Morning after pill Opiates PD Migraine Vestibular
Levodopa. MOA
Dopamine pro-drug
crosses BBB and converted into dopamine by dopa-decarboxylase
give with peripheral dopamine decarboxylase inhibitor e.g. carbidopa (co-careldopa) or benserezide (co-beneldopa)
short T1/2 therefore at least TDS
Side effects of levodopa
Dyskinesia On-off phenomena Psychosis ABP decreased Mouth dryness Insomnia N/V EDS
COntraindications to levodopa
glaucoma (closed)
MAOIs -> hypertensive crisis
Melanoma
Interactions of levodopa
Function decreased by antipsychotics
Hypertensive crisis with non-selective MOAIs
Food affects absorption
Synthetic dopamine agonists used in parkinsons disease?
ropinerole
rotigotine
pramipexole
Selegiline
example of a selective MOA-B inhibitor used in parkinsons
rasagiline
prevent intraneuronal degradation of dopamine
Used alone to delay need for L-dopa. Adjunct to L-dopa to decrease end of dose effects
Entacapone
COMT inhibitor (like tolcapone) used in PD Inhibit peripheral Da degradation
SEs: reddish-brown urine, GI, dyskinesias
Ondansetron
5HT3 receptor antagonist
anti-emetic
used post-op or after chemo
Interactions of ondansetron
Levels decreased by rifampicin, CBZ, phenytoin
Avoid with drugs that increase QT interval
Phenytoin
Anti-epileptic
Na channel blocker
Use dependent
Inhibit action potential generation
SEs phenytoin
Acute:
drowsiness
cerebellar symptoms - DANISH
rash
Chronic gingival hypertrophy hirsuitism & acne decreased folate -> megaloblatstic anaemia peripheral neuropathy lymphadenopathy
Idiosyncratic fever rashes, incl toxic epidermal necrolysis hepatitis Dupuytren's contracture aplastic anaemia drug-induced lupus
Teratogenic
associated with cleft palate and congenital heart disease
Phenytoin has many interactions as is a cytochrome P450 inducer. Contraindications?
Don’t give IV if cardiac dysrhythmias
Caution: DM, hypotension, pregnancy
Sodium valproate. SEs
Valproate Appetite increases Liver failure Pancreatitis Reversible hair loss Oedema Ataxia Teratogenicity, Tremor, thrombocytopenia Encephalopathy
Sodium valproate
first line for primary generalised epilepsy
Cytochrome p450 inhibitor
Monitor FBC, LFTs
Name SSRIs
Paroxetine
Citalopram
Fluoxetine
sertraline
SEs SSRIs
N/V Insomnia Headache Sexual dysfunction SIADH Withdrawal effects
Fluoxetine - interactions?
SSRI Interactions:
It is a p450 inhibitor so increases levels of TCAs, benzos, clozapine, haldol, cbz, phenytoin
SSRI+MOAI -> serotonin syndrome
increased risk of bleeding with aspirin
Venlafaxine
SNRI
2nd line anti-depressant
Zopliclone
used to treat insomnia
non-benzo
Pioglitazone. What is it? how does it work?
Thiazolidinediones are a new class of agents used in the treatment of type 2 diabetes mellitus.
They are agonists to the PPAR-gamma receptor and reduce peripheral insulin resistance.
Rosiglitazone was withdrawn in 2010 following concerns about the cardiovascular side-effect profile.
Gabapentin. MOA? SEs?
MOA unknown
SE: sedation, cerebellar dysfunction, dizziness and peripheral oedema
What is the function of gabapentin affected by?
decreased by: antidepressants
antimalarials
What is cephalexin
1st generation cephalosporin antibiotic- beta lactam Abx
Used for UTIs
Bactericidal - inhibit bacterial transpeptidase enzyme required for cell wall construction.
increasing generations have increasing activity against gram -ve organisms
Cefuroxime
2nd generation cephalosporin
Bactericidal beta lactam abx - inhibit transpeptidase required for cell wall construction. Gram -ve activity
Used for Mod/Severe CAP, GI sepsis, Pre-op
Cefotaxime / ceftriaxone
Cephalosporin - 3rd generation
Bactericidal
Inhibit bacterial transpeptidase enzyme. Required for cell wall construction.
Used in meningitis, epiglottis, gonorrhoea, SBP
SEs cephalosporins?
1st gen- cephalexin
2nd gen - cefuroxime
3rd gen - cefotaxime, ceftriaxone
SE: GI upset
CI: hypersensitivity reactions
Ciprofloxacin MOA. Use?
Fluroquinolone
Bactericidal - inhibit DNA synthesis. Inhibit topoisomerase II.
Broad spectrum
especially gram -ve GI infections: campylobacter, shigella, pseudomonas (esp in CF), prostatitis, PID, protozoa (giardia)
SEs fluoroquinolones?
Ciprofloxacin, Moxifloxacin, levofloxacin
increased QT interval GI upset Tendonitis + rupture: e.g. achilles tendon rupture reduced seizure threshold photosensitivity
CI: pregnancy
Interactions of fluoroquinolones
P450 inhibitor
Decreased absorption with antacids
Cyclophosphamide. Adverse effects
Acute myeloid leukaemia Bladder Cancer Haemorrhagic cystitis Infertility Bone marrow suppression Alopecia
Used as an immunosuppressant - cancer treatment, glomerulonephritis / tubulointerstitial nephritis, autoimmune conditions
Cyclophosphamide MOA
Metabolite (converted from pro-drug by ctyochrome p450 enzymes) phosphamide mustard forms cross links with DNA -> elimination of T cells
Drugs to avoid in renal failure
- antibiotics: tetracycline, nitrofurantoin
- NSAIDs
- lithium
- metformin
How to treat a TCA overdose
Management
IV bicarbonate may reduce the risk of seizures and arrhythmias in severe toxicity
arrhythmias: class 1a (e.g. Quinidine) and class Ic antiarrhythmics (e.g. Flecainide) are contraindicated as they prolong depolarisation. Class III drugs such as amiodarone should also be avoided as they prolong the QT interval. Response to lignocaine is variable
correction of acidosis is the first line in management of tricyclic induced arrhythmias
dialysis is ineffective in removing tricyclics
Management of Lithium overdose
mild-moderate toxicity may respond to volume resuscitation with normal saline
haemodialysis may be needed in severe toxicity
sodium bicarbonate is sometimes used but there is limited evidence to support this. By increasing the alkalinity of the urine it promotes lithium excretion
Rx warfarin overdose
Vit K
Prothrombin complex
Rx heparin overdose
protamine sulphate
Rx Beta blocker overdose
If bradycardic - atropine
If resistant - glucagon may be used
Rx ethylene glycol
Fomepizole = first line
Ethanol
Haemodialysis in refractory cases
Methanol poisoning treatment
Ethanol or fomepizole
Haemodialysis in refractory cases
Rx organophosphate insecticides
atropine
the role of pralidoxime is still unclear - meta-analyses to date have failed to show any clear benefit
Rx digoxin overdose
Digoxin specific antibody fragments
Rx iron overdose
Desferrioxamine, a chelating agent
Rx lead overdose
Dimercaprol, calcium edetate
Rx cyanide overdose
Hydroxocobalamin; also combination of amyl nitrite, sodium nitrite, and sodium thiosulfate
Dicobalt edentate
SEs sildenafil
PDE V inhibitor - impotence
SEs: blue discolouration of vision non-arteritic anterior ischaemic neuropathy nasal congestion flushing gastrointestinal side-effects headache
Gentamicin. MOA
aminoglycoside - bacteriocidal (amino-acyl site of 30s subunit)
other examples of amino glycosides include amikacin, streptomycin, neomycin
When is gentamicin used?
Used for gram negative sepsis
Neutropenic sepsis
Otitis externa
Anti-pseudomonal
SEs Gentamicin
nephrotoxic
Ototoxic
Toxicity of gentamicin affected by?
Toxicity increased by: furosemide cephs vanc ciclosporin
Carbapenams. MOA? Examples?
Imipenam
Meropenam
Ertapenam
Bacteriocidal - inhibit bacterial transpeptidase enzyme required for cell wall construction
V broad spectrum (gram -,+ and anaerobes & pseudomonas)
Imipenam is rapidly inactivated by the kidney and must be given with cilastatin which blocks its metabolism
When are carbapenams used?
all gram + except MRSA
most gram -ves
neutropenic sepsis
SE carbapenams
GI upset
Examples of macrolide antibiotics
clarithromycin
erythromycin
azithromycin
Bacteriostatic (50s subunit)
When is clarithromycin used?
penicillin allergies
atypical pneumonia
chlamydia
H.Pylori
SEs macrolides?
Increased QT interval
Dry skin
cholestatic hepatitis
GI prokinetic action
Interactions of macrolides
p450 inhibitor (increased dose of warfarin) Increased dose digoxin
Metronidazole
Inhibits DNA synthesis
Used for anaerobes GI sepsis Aspiration pneumonia AAC (antibiotic-assoc colitis) H.Pylori PID Protozoa: Giardia
SEs metronidazole
Metallic taste
GI upset
gynaecomastia
peripheral neuropathy
AVOID ALCOHOL - disulfiram-like reaction
as aldehyde dehydrogenase inhibitor
amphotericin B. what is it? what is it used for
anti-fungal
interacts with ergosterol -> pore formation -> fungicidal
used for severe systemic fungal infections IV such as cryptococcal meningitis, pulmonary aspergillosis, systemic candidiasis
SEs amphotericin B
nephrotoxic (monitor Cr)
IV reaction (after 1-3h) - fever, hypotension, n/v
(PO version is non-toxic)
Fluconazole. MOA
anti-fungal
blocks ergosterol synthesis by inhibiting 14 alpha-demethylase -> decreased membrane fluidity
inhibits replication
prevents hyphae formation
broad spectrum
fungistatic
When is fluconazole used
oral/vag/oesophagus candida
alternative to amphotericin B for systemic infections
(P450 inhibitor)
nystatin
anti-fungal
interacts with ergosterol -> pore formation -> fungicidal
used for candidiasis: cutaneous, vaginal, mucosal, oesophageal
toxic if given IV
Amoxicillin. MOA. USES
Inhibits bacterial transpeptidase enzyme required for cell wall construction
bactericidal
broad spectrum
USES: pneumococcus, listeria, E.coli, enterococci
Co-amoxiclav
amoxicillin
clavulinic acid
used for severe CAP , UTIs
Tazocin
piperacillin + tazobactam
severe HAP
neutropenic sepsis
Flucloxicillin
MSSA
penicillinase-resistant
Penicillin V Penicillin G (IV)
Streps
N.meningitides
syphilis
SEs of penicillins
hypersensitivity reaction: rash, anaphylaxis
GI upset
mac pap rash with EBV
Interactions of penicillins
may decrease dose of OCP
dose increased by probenecid
trimethoprim
folate antagonist
bacteriostatic
Used for UTIs, PCP, toxoplasmosis
SE: blood dyscrasias, nephro and hepato-toxicity
Vancomycin
glycopeptides
bactericidal
(inhibit cell wall synthesis)
used for aerobic and anaerobic Gm + MRSA HAN Infective endocarditis Antibiotic-assoc colitis
SE vancomycin
nephrotoxic
ototoxic (tinnitus, SNHL)
hypersensitivity rash
neutropenia
MUST MONITOR LEVELS
Bleomycin SE
degrades preformed DNA
SE: lung fibrosis
Doxorubicin. MOA? SE?
Stabilizes DNA-topoisomerase II complex inhibits DNA & RNA synthesis
SE:Cardiomyopathy
Fluorouracil MOA? SE?
Pyrimidine analogue inducing cell cycle arrest and apoptosis by blocking thymidylate synthase (works during S phase)
SEs:
Myelosuppression
mucositis
dermatitis
Vincristine / vinblastine MOA? SE?
Inhibits formation of microtubules
SE vincristine: Peripheral neuropathy (reversible) , paralytic ileus
SE vinblastine: myelosuppresion
Cisplatin MOA? SE?
Causes cross-linking in DNA
SE:
Ototoxicity
peripheral neuropathy
hypomagnesaemia
SE GTN spray?
Hypotension
Tachycardia
Headache
Flushing
Tolerance may develop
Clozapine SE
agranulocytosis
neutropenia
reduced seizure threshold
FBC monitoring essential during treatment
Osteoporosis drug causes
Heparin
Corticosteroids
Pioglitazone
Warfarin SE
haemorrhage
teratogenic, although can be used in breast-feeding mothers
skin necrosis: when warfarin is first started biosynthesis of protein C is reduced. This results in a temporary procoagulant state after initially starting warfarin, normally avoided by concurrent heparin administration. Thrombosis may occur in venules leading to skin necrosis
purple toes
Factors that potentiate warfarin
Factors that may potentiate warfarin
liver disease
P450 enzyme inhibitors, e.g.: amiodarone, ciprofloxacin
cranberry juice
drugs which displace warfarin from plasma albumin, e.g. NSAIDs
inhibit platelet function: NSAIDs
Atoraquone. What is it?
Often combined with progaunil (malarone)
Anti-malarial
take 1-2days before travel and for 7 days after
Atoraquone and Proguanil SE?
GI upset
Chloroquine SE. CI?
Anti-malarial (take 1 wk before and 4 wks after)
Taken weekly
Headache
CI: epilepsy
Doxycycline SE?
anti-malarial
Photosensitivity
Oesophagitis
Mefloquine. SE? CI?
Aka Larium
Anti-malarial (take 2-3wks before and 4 wks after)
SE: dizziness
Neuropsychiatric disturbance
CI: epilepsy
NSAIDs SE?
Abnormal LFTs (raised bilirubin &ALT) PUD decreased renal function
CI: asthma
Drug causes of pancreatitis
azathioprine ARVs prednisolone sulphasalazine didanosine bendroflumethiazide furosemide pentamidine sodium valproate
Ciclosporin SE?
Ciclosporin is an immunosuppressant which decreases clonal proliferation of T cells by reducing IL-2 release. It acts by binding to cyclophilin forming a complex which inhibits calcineurin, a phosphotase that activates various transcription factors in T cells
Adverse effects of ciclosporin (note how everything is increased - fluid, BP, K+, hair, gums, glucose) nephrotoxicity hepatotoxicity fluid retention hypertension hyperkalaemia hypertrichosis gingival hyperplasia tremor impaired glucose tolerance hyperlipidaemia increased susceptibility to severe infection
Interestingly it is ‘virtually non-myelotoxic’.
Ciclsporin indications
following organ transplantation rheumatoid arthritis psoriasis (has a direct effect on keratinocytes as well as modulating T cell function) ulcerative colitis pure red cell aplasia
What would you use to treat a patient who has taken an antiemetic and now presents with protruding tongue, spasm of jaw, uncontrolled facial grimacing and torticollis?
Benztropine
to treat an acute dystonic reaction to dopaminergic antagonists.
blocks striatal cholinergic receptors, leading to rebalancing of cholinergic and dopaminergic activity in the brain.
Name 3 anti-protozoal drugs
artesunate
quinine
chloroquine
Gliclazide
Sulphonylurea
Insulin secretagogues
Block hyperpolarising K+ channel on β cells
→ depolarisation and insulin release
Used in treatment of DM
Examples of sulphonylureas
Gliclazide
tolbutamide
glipizide
Glibenclamide
SEs sulphonylureas
Hypoglycaemia
Weight gain
GI upset
Headache
Gliclazide excretion and interactions?
Renally excreted
fx ↑d by:
- sulphonamides
- trimethoprim
- NSAIDs
- warfarin
- fibrates
Metformin
biguanide
Insulin sensitizer
- ↓ gluconeogenesis
- ↑ peripheral glucose use
- ↓ LDL and VLDL
SE metformin
and CI?
GI upset
Lactic acidosis
Renally excreted
Caution in renal or
hepatic impairment
CI:
Contrast media
General anaesthesia
Recent MI
Pioglitazone
Thiazolidinedione
Peripheral insulin sensitizer
PPAR gamma ligand (nuclear receptor
involved in glucose and lipid homeostasis)
Pioglitazone SEs?
Thiazolidinedione
SE: Wt. gain Fluid retention Hepatotoxicity May exacerbate HF Bladder cancer Fractures
Nateglinide
Repaglinide
SE?
Meglitinides
Insulin secretagogues
Block hyperpolarising K+ channel
SE: hypoglycaemia
Exenatide
Liraglutide
Insulin secretagogue
GLP-1 analogue
- ↑ insulin secretion and sensitisation
SC injection
Sitagliptin
Vildagliptin
Insulin secretagogues
Dipeptidylpeptidase-4 inhibitor
DPP-4 breaks down endogenous GLP-1
Acarbose
Intestinal α-glucosidase inhibitor
Delays carb absorption → ↓ post-prandial
blood glucose
Little effect on fasting glucose
SE:Flatulence
Loose stools/diarrhoea
Abdo pain / bloating
Hepatotoxicity (rare)
Levothyroxine
In elderly pts. c¯ subclinical heart failure thyroxine can
ppt. acute worsening: palpitations, angina, MI
-> Introduce thyroxine gradually
Excessive thyroxine → osteopaenia and AF
Carbimazole SE?
Used to treat hyperthyroidism Thionamides - thyroperoxidase inhibitors - prevent iodination of tyrosine - → ↓ T4/T3 synthesis Carbimazole is a pro-drug - converted to methimazole
SE: Agranulocytosis - often transient and benign Hypersensitvity: rash, pruritis hepatitis
Propythiouracil is reserved for those
intoleant of carbimazole due to risk of
hepatitis
Ezetimibe MOA? SE?
Used in hypercholesteraemia
Decrease cholesterol absorption in the small intestine
SE: headache
Fibrates MOA? SEs?
Agonist of PPAR-alpha therefore increases lipoprotein lipase expression
SEs: Myositis pruritis cholestasis
nicotinic acid
decreases VLDL secretion
flushing
myositis
Finasteride
Finasteride is an inhibitor of 5 alpha-reductase, an enzyme which metabolises testosterone into dihydrotestosterone
Indications
benign prostatic hyperplasia
male-pattern baldness
Adverse effects impotence decrease libido ejaculation disorders gynaecomastia and breast tenderness
Finasteride causes decreased levels of serum prostate specific antigen
