Pharmacology Flashcards
1
Q
Phase I reactions
A
oxidation, reduction, hydrolysis, by P450 enzymes or specific enzymes
Products generally more active, potentially toxic,
2
Q
Phase II reactions
A
conjugation, gucuronyl, acetyl, methyl, sulfate groups
Products typically inactive, excreted in urine/bile
3
Q
drugs undergoing significant 1st pass metabolism
A
(Love at first sight - heart related meds)
aspirin
isosorbide dinitrate
GTN
lignoicaine
propranolol
verapamil
isoprenaline
then you have steroids and testosterone
4
Q
Drugs with zero order kinetics
A
(When you lose the girl)
ethanol
MI (aspirin, heparin)
seizures (phenytoin)
5
Q
Drugs dependent on acetylator status
A
(HIgh SPeeD) Hydralazine, Isoniazid, Sulfasalazine, Procainamide, Dapsone.
6
Q
CYP 450 inducers
A
CRAPGPS carbamazepine, rifampicin, alcohol (chronic), phenytoin, griseofulvin, phenobarbitone, sulphonylureas/smoking/St John’s wort
Nevirapine as well
7
Q
CYP450 inhibitors
A
SICKFACES.COM sodium valproate, isoniazid, cimetidine, ketoconazole/fluconazole, fluoxetine/sertraline, alcohol (acute)/allopurinol/amiodarone, ciprofloxacin/chloramphenicol, erythromycin/clarithromycin, sulphonamides, cardiac/liver failure, omeprazole, metronidazole
8
Q
What happens in paracetamol overdose
A
depletion of glutathione stores (would usually conjugate to form non-toxic mercapturic acid), raised toxic NAPQI (from to mixed metabolisation by P450 oxidases). Toxins form covalent bonds with cell proteins, denaturing them, leading to cell dealth in liver + kidney.
9
Q
What is a staggered paracetamol OD?
A
Staggered OD if all tablets not within 1hr
10
Q
Initial Treatment of paracetamol OD
A
NAC (over 1hr) - precursor of glutathione → replenishes glutathione
11
Q
Indications for transplantation in Paracetamol OD
A
Transplant if: pH<7.3 24hrs post-ingestion or all of: PT>100s + Creat>300 + Grade 3 or 4 encephalopathy
12
Q
TCA overdose features and ECG
A
serotonin, noradrenergic, anti-cholinergic, anti-histamine effects. anticholinergic
sx: dry mouth, dilated pupils, agitation, sinus tachycardia, blurred vision
Severe sx: Arrhythmias, seizures, acidosis, coma
ECG: tachy, broad complex, prolonged QT. QRS>100 associated with seizures, QRS >160 assx with arrhythmias.
13
Q
TCA OD Rx
A
Rx: IV bicarbonate (if: pH<7.1, QRS>160, Arrhythmias, hypotension), lipid emulsion
14
Q
What drugs are contraindicated in TCA ODs to treat arrhythmias?
A
Class 1a (quinidine), Class 1c (flecainide), Class III (amiodarone) antiarrhythmics contraindicated as they prolong depolarisation
15
Q
Quinine toxicity/cinchonism features
A
cinchonism - hypotension, acidosis, hypoglycemia (pancreatic insulin secretion stimulated), tinnitus, flushing, visual disturbances, flash pulm oedema, dry skin, abdo pain, AKI - neuro damage permanent, difficult to distinguish from aspirin poisoning.
16
Q
Quinine toxicity ECG features:
A
long QRS, QTc, (Na, K channels blocked)
17
Q
Lithium toxicity is at what level, and when to take this dose?
A
> 1.5, taken 12hrs post-dose
18
Q
Precipitants of lithium toxicity
A
AKI, dehydration, drugs causing those + metronidazole.
19
Q
Lithium toxicity features
A
coarse tremor, hyperreflexia, confusion, polyuria, seizure, coma.
20
Q
Treatment of lithium toxicity
A
mild-mod IVF. Severe: haemodialysis. Sometimes bicarb (increases urinary alkalisation, increases excretion)
21
Q
Carbon monoxide poisoning oxygen dissociation curve shift
A
left shift, reduced oxygen saturation
22
Q
Features of CO poisoning
A
headache, N&V, vertigo, confusion, weakness, pink skin/mucosa, hyperpyrexia, arrhythmias, extrapyramidal sx, coma.
23
Q
Rx for CO poisoning
A
100% high flow oxygen min 6hrs
hyperbaric oxygen (indicated if levels>25%, LOC, neuro sx other than headache, MI, arrhythmia, pregnancy)
24
Q
Cyanide poisoning mechanism
A
inhibits cytochrome c oxidase → cessation of mitochondrial electron transfer chain.
25
Cyanide poisoning features
brick-red skin, bitter almond smell, hypoxia, hypotension, headache, confusion.
Later, ataxia, peripheral neuropathy, dermatitis.
26
Rx for cyanide poisoning
100% oxygen, hydroxocobalamin IV, inhaled amyl nitrite, IV sodium nitrite, IV sodium thiosulfate
27
Ecstasy poisoning features
neuro (agitation, anxiety, confusion, ataxia), cardio (tachy, HTN), hypoNa (SIADH or excessive water), hyperthermia, rhabdomyolysis.
28
Rx for ecstasy poisoning
supportive, dantrolene for hyperthermia if supportive fails
29
Cocaine OD features
blocks dopamine, noradrenaline, serotonin uptake.
CVS: coronary spasm, tachy/bradycardias, HTN, QRS widening, long QT, dissection.
Neuro/psych: seizures, mydriasis, hypertonia, hyperreflexia, agitation, psychosis, hallucinations.
Others: ischaemic colitis, hyperthermia, acidosis, rhabdomyolysis
30
Rx for cocaine OD
benzos
HTN: + nitroprusside
ACS: + GTN + PCI
31
Salicylate OD features
metabolic acidosis + resp alkalosis. Sx: hyperventilation (central stimulation), tinnitus, lethargy, sweating, pyrexia, N&V, hyperglycaemia/hypoglycaemia, seizures, coma.
32
Rx for salicylate OD
urinary alkalisation with IV bicarbonate, haemodialysis (indications: conc>700, acidosis resistant to treatment, AKI, pulmonary oedema, seizures, coma)
33
Ethylene Glycol toxicity features
Stage 1: like ETOH intoxication
Stage 2: metabolic acidosis, high anion gap, high osmolar gap, tachycardia, HTN
Stage 3: AKI.
34
Ethylene Glycol toxicity Rx:
fomepizole (inhibits ETOH dehydrogenase, prevents build up of toxic metaolite), ETOH competes fo ETOH dehydrogenase, haemodialysis
35
Methanol poisoning features
Sx: like ETOH intoxication + visual problems, due to formic acid buildup.
36
Rx for methanol poisoning
fomepizole or ethanol, haemodialysis, cofactor therapy with folinic acid
37
Organophosphate poisoning
DUMBELLS diarrhoea, urination, miosis/muscle weakness, bronchorrhoea/bradycardia, emesis, lacrimation, salivation/sweating.
38
Rx for organophosphate poisoning
atropine
39
Mercury poisoning common cause
lots of tuna
40
Mercury poisoning mechanism
Irreversible inhibition of selenoenzymes
41
Features of mercury poisoning
paraesthesia, visual field defects, hearing loss, irritability, RTAs. (If you can’t see or hear in an RTA, your senses get weird and you get irritable)
42
Local anaesthetic toxicity features
CNS over-activity then depression (initially blocks inhibitory pathways then blocks both inhibitory and activating), with arrhythmias.
43
Lidocaine interactions with drugs
beta blockers, ciprofloxacin, phenytoin.
44
Rx for lidocaine/local anaesthetic toxicity
Lipid emulsion
45
Management for caustic substance ingestion
urgent upper GI surgical referral if perforation. Do not neutralise. High dose IV PPI.
Upper GI endoscopy if symptomatic.
Asymptomatic - discharge after oral fluid trial + observation.
46
Complications of caustic substance ingestion
ulceration, perforation, airway injury/compromise, aspiration, infection, electrolytes (eg hypoCa in hydrofluoric acid ingestion)
Chronic; strictures, fistulae, gastric outlet obstruction, upper GI Ca (1000-3000x risk)
47
Side effect of erythropoietin
pure red cell aplasia
48
Rifampicin SEs:
hepatitis, orange secretions, flu-like sx, CYP450 inducer
49
Isoniazid MoA:
inhibits mycolic acid synthesis
50
Isoniazid SEs:
peripheral neuropathy (give pyridoxine vit b6), hepatitis, agranulocytosis, liver enzyme inhibitor
51
Pyrazinamide MoA:
converted by pyrazinamidase to pyrazinoic acid which inhibits fatty acid synthase (FAS) I.
52
Pyrazinamide SEs:
arthralgia, myalgia, hepatitis
53
Ethambutol MoAs
nhibits arabiosyl transferase which polymerises arabinose to arabian.
54
Ethambutol SEs:
optic neuritis (check visual acuity before and during treatment), renally excreted - dose needs adjusting with renal impairment
55
ODs that can be treated with haemodialysis
BLAST barbiturates, lithium, alcohol (including methanol), salicylates, theophylline (charcoal haemoperfusion preferred)
56
Serotonin syndrome features:
neuromuscular excitation (hyperreflexia, myoclonus, rigidity)
autonomic nervous system excitation
(hyperthermia, sweating)
altered mental state
confusion
57
Serotonin syndrome Rx:
IVF
Benzos
Cyproheptadine
58
Drugs causing thrombocytopenia
HANDQ - heparin, AEDs (carbamazepine, valproate, Abx (penicillins, sulphonamides, rifamipicin), Abciximab, NSAIDs, diuretics, Quinine.
59
Ciclosporin MoA
Reduces IL2 release, forms complex with cyclophilin, inhibits calcineurin, reduces T cell proliferation.
60
Indications for ciclosporin
Organ transplant, Rh Arth, psoriasis, UC, pure red cell aplasia.
61
Is ciclosporin myelotoxic?
No
62
ciclosporin SEs:
renal, liver, everything increased/hyper (fluid, bp, K, hair, gums, glucose, lipids), tremor, infection.
63
When to check ciclosporin level
immediately before dose
64
Tacrolimus MoA
reduces IL2 release, binds to FKBP, complex inhibits calcineurin
65
Compare ciclosporin vs tacrolimus
Tacrolimus more potent, more nephrotoxic, results in more impaired glucose tolerance
66
Gynaecomastia drugs
DISCO (digoxin, isoniazid, spironolactone, cimetidine, oestrogen), finasteride
67
gingival hyperplasia causes
PACC phenytoin, AML, ciclosporin, CCBs.
68
Hydralazine MoA
elevates cGMP, smooth muscle relaxation in arterioles.
69
Hydralazine contraindications
SLE, IHD, CVA.
70
Indication for Hydralazine in HF
Afro-Caribbeans
Only to be given with nitrates
71
Ivabradine MoA
Inhibits funny channels
72
Indication for Ivabradine in HF
LVEF<35%
sinus, rate >75bpm (blocks cardiac pacing channels so contraindicated for lower resting HRs)
73
List some centrally acting anti-HTN meds
methyldopa, moxonidine, clonidine (alpha 2 agonism in vasomotor centre)
74
MoA for bivalirudin
direct thrombin inhibitor
75
Adenosine MoA
A1 agnoism at AV node, inhibits adenylyl cyclase, reduces cAMP, increases K efflux
76
Half-life of adenosine
8-10s
77
Interactions with adenosine (the 2 important ones)
DEAR:
dipyridamole enhances action
aminophylline reduces action
78
Nicorandil MoA
guanylyl cyclase activation, cGMP increase
Acts both as nitrate and non-selective ATP-sensitive K channel activator (in smooth muscles) → hyperpolarisation, relaxation→ increased blood flow to myocardium + reduction of workload
79
Nicorandil SEs:
headache, flushing, anal/GI ulcerations.
80
Nicorandil contraindication
LVF
81
Dipyridamole MoA
non-specific phosphodiesterase inhibitor, antiplatelet (given post CVA/TIA if clopidogrel not tolerated)
Elevates cAMP, reduces intracellular Ca. reduces adenosine uptake, inhibits thromboxane synthase
82
Aspirin MoA
irreversible COX1,2 inhibitor. Thromboxane A2 blocked → reduced pltlt aggregation.
83
Interactions with aspirin
oral hypoglycaemics, warfarin, steroids potentiate action
84
Clopidogrel MoA
P2Y12 inhibitor, irreversible Adenosine diphosphate receptor antagonist on platelets.
85
Clopidogrel and PPIs
Less effective with it but lansoprazole ok
86
Ticagrelor MoA
inhibits adenosine deaminase, inhibits adenosine clearance, causes dyspnoea
87
Tirofiban MoA
anti-GIIb/IIIa → prevents fibrinogen binding → blocks pltlt aggreg (others of same class: abciximab, eptifibatide)
88
Thiazides SE:
hypoK, Na, hyperCa/hypercalciuria, postural hypotension, gout, impotence, impaired glucose tolerance, thrombocytopenia, agranulocytosis, pancreatitis, photosensitivity rash
89
Furosemide SE
hypoNa, Mg, Ca, hypochloraemic alkalosis, ototoxicity, gout, AKI, low bp, hyperglycaemia
90
K sparing diuretics types
Epithelial sodium channel blockers: amiloride (in DCT), triamterene
Aldosterone antagonists: spironolactone, eplerenone
91
Naftidrofuryl MoA
5HT2 antagonist for PAD, vasodilator
92
Cilostazol MoA
PDE III inhibitor - vasodilator, antiplatelet, for PAD
93
Vaughan Williams classification
1: Na channel
2: beta blockers
3: K channel
4: Ca channel
94
Class Ia anti-arrhythmics
increases AP duration: Quinidine/procainamide/disopyramide. SE: quinidine- cinchonism (headache, tinnitus, thrombocytopenia), procainamide- drug-induced lupus
95
Class Ib anti-arrhythmics
reduces AP duration: lidocaine/mexiletine/tocainide
96
class Ic anti-arrhythmics
no AP change: encainide, propafenone
97
Flecainide MoA
Nav1.5 Na channel
98
Flecainide contraindications
post-MI, HF, sinus node dysfunction/AV block, a flutter.
99
Flecainide SE:
negatively inotropic, bradycardia, proarrhythmic (widened QRS, prolonged PR, oral paraesthesia, visual disturbance)
100
Beta blocker SEs:
bronchospasm, fatigue, cold periph, sleep dist
101
Examples of class III anti-arrhythmics
amiodarone, sotalol, ibutilide, bretylium
102
amiodarone half-life
20-100 days
103
What to monitor and when for amiodarone
TFTs, LFTs, U&Es, CXR pre-Rx then TFT, LFT every 6 months
104
Amiodarone SEs:
thyroid, corneal deposits, lungs, liver, periph neuropathy, photosensitivity, slate grey appearance, bradycardia, long QTc, thrombophlebitis
Amiodarone induced hypothyroidism: Wolff-Chaikoff effect. Rx: can continue + give thyroxine
Amiodarone induced thyrotoxicosis:
Type 1: excess iodine-induced thyroid hormone synthesis, goitre present. Rx: carbimazole or potassium perchlorate
Type 2: destructive thyroiditis. Rx: steroids
105
Verapamil SEs/cautions
avoid in VT, HF, constipation, hypotension, bradycardia, flushing
106
Diltiazem SE/Cautions
hypotension, bradycardia, HF, ankle swelling
107
Nifedipine/amlodipine/felodipine SEs:
(dihydropyridine - not an anti-arrhythmic): SE: flushing, headache, ankle swelling
108
Digoxin MoA
inhibition of Na/K ATP-ase pump, stimulates vagus, blocks AV node
109
When to measure digoxin levels
when toxicity suspected,
within 8-12 hrs of last dose
110
ECG features with digoxin toxicity
down-sloping ST depression (reverse tick), flattened T, shortened QT, AV block/bradycardia.
111
Risk factors for digoxin toxicity
hypoK, hypoMg, hyperCa, hyperNa, acidosis, hypothermia, hypothyroid, increasing age, renal failure, MI, amiodarone, quinidine, verapamil, diltiazem, spironolactone (competes for DCT secretion), ciclosporin, thiazides, furosemide. Rx: digibind, correct arrhythmias, monitor potassium
112
Features of digoxin toxicity
lethargy, N&V, anorexia, confusion, yellow-green vision, brady-arrhythmias, gynaecomastia.
113
alpha 1 agonists
phenylephrine (vasoconstriction, GI sm relaxation, salivary secretion, hepatic glycogenolysis). Activates phospholipase C → IP3 → DAG
114
Alpha 2 agonist
clonidine (presynaptic inhibition, inhibits insulin, pltlt aggregation). Inhibits adenylate cyclase
115
Beta 1 agonist
dobutamine (ionotropic + chronotropic). Stimulates adenylate cyclase
116
Beta 2 agonists
salbutamol (bronchodilation, vasodilation, GI sm relaxation). Stimulates adenylate cyclase
117
Beta 3 agonist
(lipolysis). Stimulates adenylate cyclase
118
Adrenaline actions:
induces hyperglycaemia, hyperlactataemia, hypokalaemia, low insulin.
Alpha agonist: inhibits pancreatic insulin secretion, stimulates hepatic and muscular glycogenolysis, stimulates muscular glycolysis.
Beta agonist: stimulates pancreatic glucagon secretion, stimulates ACTH, stimulates lipolysis
119
Accidntal adrenaline injection Rx:
local infiltration of phentolamine (alpha 1+ 2 blocker)
120
Alpha 1 antagonist
doxazosin
Alpha1a: tamsulosin
121
Alpha 2 antagonist
yohimbine
122
Alpha non-selective antagonist
phenoxybenzamine,
phentolamine
123
beta 1 antagoist
atenololb
124
beta non-selective antagonist
propanolol
125
mixed alpha beta blocker
carvedilol, labetalol
126
What is a hybridoma
fusion of myeloma cells + mouse splenic cells
127
What is 'humanising' in making mAbs?
Humanising involves combining variable mouse region with human constant region
128
Infliximab MoA and uses
anti-TNFa
RhArth, Crohns
129
Rituximab MoA and uses
anti-CD20, non-Hodkin’s, Rh Arthr
130
Cetuximab MoA and uses
EGFR, met colorectal Ca, head and neck
131
Erlotinib MoA and uses
EGFR, lung Ca
132
Trastuzumab MoA and uses
(herceptin) Her2/neu receptor, met breast Ca.
133
Trastuzumab caution before use
Must do Echo before due to cardiotoxicity (more common when anthracyclines also used)
134
Alemtuzumab MoA and use
anti-CD52, CLL
135
Abciximab MoA and use
GpIIb/IIIa, IHD for PCI
136
OKT3 MoA and use
anti-CD3 organ rejection
137
Nivolumab MoA and use
anti-PD1, met melanoma, lymphoma (used with ipilimumab)
138
Bevacizumab MoA and use
VEGF, colorectal Ca
139
Crizotinib MoA and use
ALK-1, NSCLC
140
Ipilimumab MoA
CTLA-4
141
Drugs causing urticaria
NAPPi - NSAIDs, aspirin, penicillins, oPiates
142
Heparin MoA
activates antithrombin III.
unfractionated: complex inhibits thrombin, factors 9a, 10a, 11a, 12a.
LMWH: complex inhibits 10a,
143
Heparin SEs:
bleeding, thrombocytopenia (heparin-induced thrombocytopenia: abs vs PF4 + heparin, develops after 5-10 days, actually prothrombotic, may need ongoing anticoagulation with direct thrombin inhibitor/danaparoid), osteoporosis, hyperkalaemia (inhibits aldosterone secretion)
LMWF has lower risk of HIT
144
Penicillin, cephalosporins, carbopenems MoA
inhibits peptidoglycan cross-linking, inhibiting cell wall formation
145
Glycopeptide MoA
inhibits peptidoglycan synthesis
146
Ribosomal 30S subunit inhibitors
aminoglycosides, tetracyclines
147
Ribosomal 50S subunit inhibitors
Macrolides, chloramphenicol, clindamycin, linezolid, streptogrammins
148
Gentamicin SE:
ototoxicity, nephrotoxicity (ATN).
149
Gentamicin contraindication
myasthenia
150
Monitoring of gentamicin
Peak + trouh levels
151
Quinolone MoA
Inhibits topoisomerase II (DNA gyrase) and IV
152
Mechanism of resistance to Quinolones
mutations to DNA gyrase, efflux pumps
153
Quinolones SE:
lowers seizure threshold, tendon damage (increased with steroids), cartilage damage, long QTc.
154
Quinolones contraindications
pregnancy/breastfeeding
G6PD deficiency
155
Metronidazole MoA
damages DNA
156
Sulphonamides, trimethoprim MoA
inhibits folic acid formation
157
Rifampicin MoA
inhibits RNA synthesis
158
ACE inhibitor teratogenecity
renal dysgenesis, craniofacial abnormalities
159
ETOH teratogenecity
craniofacial abnormalities
160
Aminoglycoside teratogenecity
ototoxicity
161
Carbamazepine teratogenecity
NTD, craniofacial abn
162
Chloramphenicol teratogenecity
grey baby syndrome
163
Cocaine teratogenecity
IUGR, preterm labour
164
Diethylstillbesterol teratogenecity
vaginal clear cell adenocarcinoma
165
Lithium teratogenecity
Ebstein's anomaly
166
Maternal DM teratogenecity
Macrosomia, NTDs, polyhydramnios, preterm labour, caudal regression syndrome
167
Smoking teratogenecity
Preterm labour, IUGR
168
Tetracyclines teratogenecity
Discoloured teeth
169
Thalidomide teratogenecity
Limb reduction defects
170
Valproate teratogenecity
NTD, craniofacial abnormalities
171
Warfarin teratogenecity
craniofacial abnormalities
172
Motion sickness Rx
Hyoscine patch> cyclizine/cinnarizine (non-sedating anti histamines)>promethazine
173
Oculogyric crisis features
restlessness, agitation, upward deviation eyes
174
Causes of oculogyric crisis
antipsychotics, metoclopramide, post-encephalitic PD
175
Rx of oculogyric crisis
benztropine, procyclidine
176
Allopurinol. How to use for gout
100mg OD initial dose for gout, to titrate every few wks for serum uric acid <300, with colchicine cover to be considered.
177
SE of allopurinol
derm (severe cutaneous adverse reaction, DRESS, Stevens-Johnson syndrome, East Asians more at risk - HLA-B*5801 screening for high cutaneous risk).
178
HLA type spcific for risk of severe cutaneous reaction to allopurinol
HLA-B*5801 in East Asians
179
Allopurinol interactions
azathioprine (as xanthine oxidase oxidises 6-mercaptopurine to 6-thiouric acid), cyclophosphamide (allopurinol reduces renal clearance), theophylline (inhibits breakdown)
180
DRESS causes
Causes: allopurinol, AEDs, Abx, immunosuppressants, HIV Rx, NSAIDs.
181
DRESS Dx
3 of: hospitalisation, reaction suspected, acute skin rash, fever, lymphadenopathy at least 2 sites, at least 1 internal organ involved, blood abnormalities. Skin biopsy: inflammatory infiltrate
182
Skin manifestations of DRESS
morbilliform rash 80%, exfoliative dermatitis with high fever, vesicles, bullae, erythroderma 10%, mucosal involvement 25%, facial swelling 30%, 2-8wks after starting offending drug
183
Bloods in DRESS
raised/low WCC, eosinophilia 30%>2.0, thrombocytopaenia, anaemia, atypical lymphocyte. Lymphadenopathy 75%
184
Liver in DRESS
hepatomegaly, hepatitis, rarely hepatic necrosis
185
Lungs in DRESS
pneumonitis, pleuritis, pneumonia
186
Kidney in DRESS
10% usually mild kidney disease (interstitial nephritis common)
187
Heart in DRESS
Myocarditis, pericarditis
188
Neuro in DRESS
meningitis, encephalitis
189
GI in DRESS
upset, acute colitis, pancreatitis
190
Endocrine in DRESS
thyroiditis, diabetes
191
Statins SE:
myopathy (simvastatin, atorvastatin>rosuvastatin, pravastatin, fluvastatin), liver impairment
192
Statin monitoring
LFTs at baseline, 3 months, 12 months, stop statin if >3x ULN
193
Statin contraindication:
macrolides
pregnancy
194
Ezetimibe MoA
reduces small intestinal cholesterol absorption.
195
Ezetimibe SE:
headache
196
Nicotinic acid MOA
reduces hepatic VLDL secretion.
197
Nitotinic acid SE
flushing
myositis
198
Fibrates MOA
PPAR-alpha agonist, increases lipoprotein lipase expression.
199
Fibrates SE
myositis
pruritis
cholestasis
VTE
200
Cholestyramine MOA
reduces small intestine bile acid reabsorption, upregulates cholesterol converted to bile acid.
201
Cholestyramine SE
GI upset, cholesterol gallstones, may raise triglyceride levels, reduces absorption of fat soluble vitamins
202
Hypomagnesaemia causes
PPIs, diuretics, TPN, ETOH, diarrhoea (magnesium can also result in diarrhoea when given orally), hypoK, hyperCa (Ca and Mg compete in thick ascending Loop of Henle), Gitelman’s, Bartter’s.
203
HypoMg features
similar to hypoCa. ECG: similar to hypoK. Exacerbates digoxin tox.
204
Causes of agranulocytosis (Drugs)
thyroid drugs (carbimazole, propylthiouracil) atypical antipsychotics (clozapine), AEDs (carbamazepine), Abx (penicillin, chloramphenicol, co-trim), mirtazapine, methotrexate
205
Drug causes of photosensitivity
TANS in Pic Thiazides, tetracyclines, amiodarone, NSAIDs, sulphonamides, psoralens, ciprofloxacin
206
Drug-induced impaired glucose tolerance
TASTIN thiazides, antipsychotics, steroids, tacrolimus/ciclosporin, IFN alpha, nicotinic acid. Beta blockers slight
207
Dopamine receptor agonists examples
ropinirole, apomorphine. Bromocriptine, cabergoline (ergot-derived)
208
Dopamine receptor agonist SE:
(ergot-derived) SE: pulmonary, retroperitoneal, cardiac fibrosis (requires ESR, creatinine, CXR).
General SE: N&V, postural hypotension, hallucinations, daytime somnolence
209
octreotide MoA
long-actin somatostatin analogue, inhibits GH, glucagon, insulin.
210
Octreotide SE:
gallstones (2 to biliary stasis)
211
COCP precaution with abx
none except with rifampicin/rifaximin
212
Muscarinic agonists
Pilocarpine: glaucoma, M1-3 receptors, contraction of ciliary body in eye relieving pressure, miosis. Also induces salivation
213
Muscarinic antagonists
atropine, ipratropium/tiotropium, oxybutynin
214
Nicotinic agonist examples
nicotine, vaerenicicline, suxamethonium
215
Nicotinic antagonist examples
Atracurium, Vecuronium, pancuronium
216
Suxamethonium MOA and uses
depolarising muscle relaxant. Inhibits ACh at NMJ, degraded by acetylcholinesterase and cholinesterase.
Fastest onset, shortest duration of action of all muscle relaxants (best for Rapid Sequence Induction). Produces generalised muscular contraction pre-paralysis.
217
Suxamethonium SE
hyperK, malignant hyperthermia, lack of acetylcholinesterase
218
Atracurium MoA, metabolism
Non-depolarising muscle relaxant. Nicotinic antagonist. Duration of action 30-45mins.
Metabolism: hydrolysis (non-hepatic/renal excretion). Reversed by neostigmine.
219
Atracurium SE
facial flushing, tachycardia, hypotension due to generalised histamine release on administration.
220
Vecuronium action, metabolism
non-depolarising. Duration of action 30-40 mins. Hepatic + Renal metabolism, effects prolonged in organ dysfunction. Reversed by neostigmine
221
Pancuronium action, metabolism
onset 2-3 minutes, duration of action 2 hrs. Reversed with neostigmine.
222
Drugs causing cataracts
steroids
223
Drugs causing corneal opacities
amiodarone
indomethacin
224
drugs causing optic neuritis
ethambutol
amiodarone
metronidazole
225
Drugs causing retinopathy
chloroquine, quinine
226
Sildenafil SE
blue discolouration, non-arteritic anterior ischaemic neuropathy, nasal congestion, flushing, GI upset, headache, priapism
227
Sildenafil contraindication
nitrates/nicorandil, hypotension, recent CVA/MI
228
Drug causing lung fibrosis
CRANE cytotoxics (bleomycin, busulphan), anti-Rheumatoid (methotrexate, sulfasalazine), amiodarone, nitrofurantoin, ergot-derived dopaminergics (bromocriptine, cabergoline, pergolide)
229
Drugs causing urinary retention
NO TAD NSAIDS, Opioids, TCAs, Anticholinergics, Dispyramide.
230
Drugs contraindicated in pregnancy
Abx: tetracyclines, aminoglycosides, sulphonamides (trimethoprim), quinolones
ACEi, ARBs, statins, warfarin, sulfonylureas, retinoids, cytotoxic agents
AEDs are potentially harmful
231
Drugs contraindicated in breastfeeding
cipro, doxy, chloramphenicol, sulphonamides, lithium, benzos, aspirin, carbimazole, methotrexate, sulfonylureas, cytotoxics, amiodarone, high dose steroids
232
Advantages vs disadvantages of progesterone only pill
Advantages: effective, no sex issues, reversible on stopping, can use with breastfeeding, can be used in smokers>35yrs, in women with VTE hx
Disadvantages: irregular periods (most common), functional ovarian cysts, weight gain, breast tenderness, acne, headaches (goes away after first few months)
233
Contraindications in COCP
UKMEC4: age>35yrs + 15cigs/day, migraine with aura, VTE/IHD/CVA hx, breast feeding <6wks post-partum, uncontrolled HTN, current breast Ca, major surgery with prolonged immobilisation, antiphospholipid abs
UKMEC3: >35yrs less than 15 cigs/day, BMI>35, VTE fhx 1st deg relatives <45yrs, uncontrolled HTN, immobility, BRCA1/2/breast Ca gene mutation, current GB disease
234
Propofol
GABA agonist, rapid onset, anti-emetic, moderate myocardial depression, little metabolite accumulation
235
Sodium thiopentone
rapid onset, marked myocardial depression, quick build-up of metabolites, not for maintenance infusion, little analgesic
236
Ketamine
NMDA antagonist, induction of anaesthesia, moderate-strong analgesic, little myocardial depression, may induce dissociative anaesthesia state with nightmares
237
Etomidate
favorable cardiac safety, little haemodynamic instability, no analgesic properties, unsuitable for prolonged sedation, adrenal suppression.
238
Botulinum toxin indications
blepharospasm, hemifacial spasm, focal spasticity, spasmodic torticollis, severe hyperhidrosis (axillae), achalasia
