Pharmacology Flashcards

1
Q

Drugs causing lung fibrosis?

A
  1. Amiodarone
  2. Anti-rheumatoid = Methotrexate, sulfasalazine
  3. Cytotoxic = busulphan, bleomycin
  4. Ergot-derived dopamine receptor agonists = bromocriptine, cabergoline, pergolide
  5. Nitrofurantoin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Most common feature of CO poisoning?

A

Headache

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Features of CO toxicity?

A
  1. Headache
  2. N&V
  3. Vertigo
  4. Confusion
  5. Subjective weakness
  6. Severe toxicity = pink skin and toxicity, hyperpyrexia, arrhythmias, extrapyramidal features, coma, death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Typical carboxyhaemoglobin level?

A
  1. <3% non-smokers
  2. <10% smokers
  3. 10-30% symptomatic = headache, vomiting
  4. > 30% severe toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

CO poisoning Rx?

A
  1. 100% high flow O2 via non-rebreather mask (min 6h, target SpO2 100%, Rx until all symptoms resolved)
  2. Hyperbaric oxygen (if LOC at any point, neurological signs, myocardial ischaemia/arrhythmia, pregnancy)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

TB drugs?

A

Rifampicin
Isoniazid
Pyrazinamide
Ethambutol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Rifampicin mushkies?

A
  1. MOA = inhibits bacterial DNA dependent RNA polymerase, preventing transcription of DNA into mRNA
  2. Potent liver enzyme inducer
  3. Hepatitis, orange secretions
  4. Flu-like symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Isoniazid mushkies?

A
  1. MOA = inhibits mycolic acid synthesis
  2. Peripheral neuropathy = prevent with pyridoxine (Vitamin B6)
  3. Hepatitis, agranulocytosis
  4. Liver enzyme inducer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pyrazinamide mushkies?

A
  1. MOA = converted by pyrazinamidase into pyrazinoic acid which in turn inhibits fatty acid synthase (FAS) I
  2. Hyperuricaemia causing gout
  3. Arthralgia, myalgia
  4. Hepatitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Ethambutol mushkies?

A
  1. MOA = inhibits the enzyme arabinosyl transferase which polymerizes arabinose into arabinan
  2. Optic neuritis = check visual acuity before and during treatment
  3. Dose needs adjusting in patients with renal impairment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Metformin MOA?

A
  1. Activation of AMP-activated protein kinase
  2. Increases insulin sensitivity
  3. Decreases hepatic gluconeogenesis
  4. May reduce gastrointestinal absorption of carbohydrates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Metformin s/e?

A
  1. GI upset intolerable in 20% (nausea, anorexia, diarrhoea)
  2. Reduced Vitamin B12 absorption (rarely a clinical problem)
  3. Lactic acidosis with severe liver disease or renal failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Metformin contraindications?

A
  1. CKD eGFR <30 or Cr > 150
  2. Lactic acidosis during period where there is tissue hypoxia
  3. Iodine-containing X-ray contrast media (discontinue metformin on day of procedure and 48h after)
  4. Alcohol abuse is a relative contraindication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Starting metformin mushkies?

A
  1. Titrated up slowly to reduce incidence of GI side effects
  2. If pts develop unacceptable s/e then modified-release metformin should be considered
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Verapamil mushkies?

A
  1. Angina, hypertension, arrhythmias
  2. Highly negatively inotropic
  3. Should not be given with beta blocker as may cause heart block
  4. S/e = HF, constipation, hypotension, bradycardia, flushing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Diltiazem mushkies?

A
  1. Angina, hypertension
  2. Less negatively inotropic than verapamil but caution should still be exercised when patients have heart failure or are taking beta-blockers
  3. S/e = hypotension, bradycardia, HF, ankle swelling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Nifedipine, amlodipine, felodipine mushkies

A
  1. Dihydropyridines
  2. Hypertension, angina, Raynaud’s
  3. Affects the peripheral vascular smooth muscle more than the myocardium and therefore do not result in worsening of HF but may therefore may cause ankle swelling
  4. Flushing, headache, ankle swelling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Amiodarone s/e?

A
  1. Thyroid (hyper and hypo)
  2. Lung fibrosis
  3. Liver fibrosis
  4. Corneal deposits
  5. Peripheral neuropathy/myopathy
  6. Photosensitivity
  7. Slate-grey appearance
  8. Thrombophlebitis and injection site reactions
  9. Bradycardia
  10. Lengthens QTi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Important amiodarone interactions?

A
  1. Decreased metabolism of warfarin, therefore increased INR
  2. Increased Digoxin levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Statin monitoring?

A

LFTS at baseline, 3m, 12m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

ACEi monitoring?

A

U&E prior to treatment, after increasing dose, annually

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Amiodarone monitoring?

A
  1. TFT, LFT U&E, CXR prior
  2. TFT, LFT every 6m
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Methotrexate monitoring?

A

FBC, U&E, LFTs = before starting, weekly until therapy established, then every 2-3 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Azathioprine monitoring?

A
  1. FBC and LFT before
  2. FBC weekly for first 4w
  3. FBC, LFT every 3m
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Lithium monitoring?
1. U&E, TFT prior to treatment 2. Lithium weekly until stabilised then every 3m 3. TFT, U&E every 6m
26
Sodium valproate monitoring?
1. FBC, LFT before treatment 2. LFT 'periodically' during first 6m
27
Glitazone monitoring?
1. LFT before 2. LFT 'regularly' during treatment
28
PDE5 inhibitor MOA?
Cause vasodilation through an increase in cGMP leading to smooth muscle relaxation in blood vessels supplying the corpus cavernosum
29
PDE5 inhibitor examples?
1. Sildafenil - Viagra = short acting, usually taken 1 hour before sexual activity 2. Tadalafil = Cialis = Longer acting than sildafenil, may be taken on regular basis eg. OD
30
PDE5 inhibitor indications?
Erectile dysfunction and Pulmonary HTN
31
PDE5i contraindications?
1. Nitrates and nicorandil 2. Hypotension 3. Recent stroke or MI (NICE recommend waiting 6m)
32
PDE5i s/e?
1. Visual disturbances = blue discolouration, non-arteritic anterior ischaemic neuropathy 2. Nasal congestion 3. Flushing 4. GI side effects 5. Headache 6. Priapism
33
What is HRT?
Involves the use of a small dose of oestrogen, combined with a progestogen (in women with a uterus), to help alleviate menopausal symptoms
34
HRT indications?
1. Vasomotor symptoms e.g. flushing, insomnia, headaches = most important factor in choosing whether to start, other indications such as reversal of vaginal atrophy should be treated with other agents as first line therapies 2. Premature menopause = should be continued until age of 50 years, most important reason in giving HRT to younger women is preventing the development of osteoporosis
35
HRT choice of hormone?
1. Oestrogens = 'natural' oestrogens such as estradiol, estrone and conjugated oestrogen are generally used rather than synthetic oestrogens such as ethinylestradiol (which is used in the combined oral contraceptive pill) 2. Progestogens = 'synthetic' progestogens such as medroxyprogesterone, norethisterone, levonorgestrel, and drospirenone are usually used. a levonorgestrel-releasing intrauterine system (e.g. Mirena) may be used as the progestogen component of HRT, i.e. a woman could take an oral oestrogen and have endometrial protection using a Mirena coil 3. Tibolone = synthetic compound with both oestrogenic, progestogenic, and androgenic activity
36
HRT route?
1. Can be taken orally or transdermally (via a patch or gel) 2. Transdermal is preferred if the woman is at risk of venous thromboembolism (VTE), as the rates of VTE do not appear to rise with transdermal preparations
37
Why do you need to give progesterone if still have a uterus?
Unopposed oestrogen can increase risk of endometrial cancer
38
Cyclical combined HRT indication?
If their LMP was less than 1 year ago
39
Continuous combines HRT indication?
1. If taken cyclical combined for at least 1 year or 2. It has been at least 1 year since their LMP or 3. It has been at least 2 years since their LMP if they have had a premature menopause
40
Premature menopause age?
< 40 y/o
41
Vasomotor symptom control if unwilling to take HRT?
1. SSRI 2. SNRI 3. Clonidine 4. Gabapentin
42
Cytochrome P450 enzyme induces?
PC BRASSS 1. Phenytoin 2. Carbamazepine 3. Barbiturates 4. Rifampicin 5. Alcohol (chronic) 6. Sulfonylureas 7. St John's Wort 8. Smoking
43
Cytochrome P450 enzyme inhibitors?
AO DEVICES GR 1. Allopurinol, antifungals, amiodarone 2. Omeprazole 3. Disulfiram 4. Erythromycin 5. Valproate 6. Isoniazid 7. Clarithromycin, ciprofloxacin 8. Ethanol (acute) 9. Sulphonamides, SSRIs 10. Grapefruit juice 11. Ritonavir
44
Yellow-green vision?
Digoxin
45
Gentamicin s/e?
1. Ototoxocity = due to auditory or vestibular nerve damage 2. Irreversible
46
Nephrotoxocity s/e?
1. Accumulates in renal failure 2. This toxicity is secondary to ATN 3. Concomitant use of furosemide increases risk 4. Lower doses and more frequent monitoring is required
47
Gentamicin C/I?
Myasthenia gravis (can cause clinically significant muscle weakness in myasthenia patients resulting in respiratory depression)
48
Gentamicin dosing?
1. Peak (1 hour after administration) and trough levels (just before the next dose) are measured 2. If the trough (pre-dose) level is high the interval between the doses should be increased 3. If the peak (post-dose) level is high the dose should be decreased
49
What classically predisposed to digoxin toxicity?
Hypokalaemia
50
Digoxin MOA?
1. Cardiac glycoside 2. Mainly used for rate control in AF 3. As has positive inotropic properties sometimes used for improving symptoms, but not mortality, in pts with HF 4. Decreases conduction through AVN which slows the ventricular rate in AF and flutter 5. Increases force of cardiac muscle contraction due to inhibition of the Na/K ATPase, also stimulates vagus nerve 6. Has a narrow therapeutic index
51
Digoxin monitoring?
1. Not monitored routinely, except in suspected toxicity 2. If toxicity is suspected, digoxin concentrations should be measured within 8-12 hours of the last dose
52
Digoxin toxicity plasma concentration?
Plasma concentration alone does not determine whether a patient has developed digoxin toxicity. Toxicity may occur even when the concentration is within the therapeutic range. The BNF advises that the likelihood of toxicity increases progressively from 1.5 to 3 mcg/l.
53
Digoxin toxicity features?
1. Generally unwell, lethargy, N&V, anorexia, confusion, yellow-green vision 2. Arrhythmias (AV block, bradycardia) 3. Gynaecomastia
54
Precipitating factor for digoxin toxicity?
1. Hypokalaemia 2. Age 3. Renal failure 4. MI 5. Hypo = magnesium, albumin, thermia, thyroidism 6. Hyper = calcium, sodium, acidosis
55
Digoxin toxicity management?
1. Digibind 2. Correct arrhythmias 3. Monitor potassium
56
Finasteride indications?
1. BPH 2. Male-pattern baldness
57
Finasteride s/e?
1. Impotence 2. Decreased libido 3. Ejaculation disorders 4. Gynaecomastia and breast tenderness
58
Finasteride effect on PSA?
Lowers it
59
Abx contraindicated in pregnancy?
1. Tetracyclines 2. Aminoglycosides 3. Sulphonamides and trimethoprim 4. Quinolones
60
Drugs contraindicated in pregnancy?
1. ACEi, ARB 2. Statins 3. Warfarin 4. Sulfonylureas 5. Retinoids (including topical) 6. Cytotoxic agents
61
ACEi teratogen?
1. Renal dysgenesis 2. Craniofacial abnormalities
62
Alcohol teratogen?
Craniofacial abnormality
63
Aminoglycoside teratogen?
Ototoxicity
64
Carbamazepine teratogen?
1. Neural tube defects 2. Craniofacial abnormalities
65
Chloramphenicol teratogen?
'Grey baby' syndrome
66
Cocaine teratogen?
1. IUGR 2. Preterm labour
67
Diethylstilbesterol teratogen?
Vaginal clear cell adenocarcinoma
68
Lithium teratogen?
Ebstein's anomaly (atrialisation of the RV)
69
Maternal DM teratogen?
1. Macrosomia 2. NTDs 3. Polyhydramnios 4. Preterm labour 5. Caudal regression syndrome
70
Smoking teratogen?
1. IUGR 2. Preterm labour
71
Tetracycline teratogen?
Discoloured teeth
72
Thalidomide teratogen?
Limb reduction defects
73
Valproate teratogen?
1. NTD 2. Craniofacial abnormalities
74
Warfarin teratogen?
Craniofacial abnormalities
75
P450 system Isoniazid?
Isoniazid inhibits
76
How slowly should metformin be titrated?
At least 1 week before increasing dose to reduce risk of developing GI side effects
77
St John's Wort mushkies?
1. Shown to be as effective as TCAs in the treatment of mild-moderate depression 2. MOA = similar to SSRIs (although SNRI also been demonstrated)
78
St John's Wort adverse effects?
1. Can cause serotonin syndrome 2. Inducer of P450 system, therefore decreased levels of drugs such as warfarin, ciclosporin. The effectiveness of the combined oral contraceptive pill may also be reduced
79
Drugs causing corneal opacities?
Amiodarone and Indomethacin
80
Drug causing cataracts?
Steroids
81
Drugs causing optic neuritis?
1. Ethambutol 2. Amiodarone 3. Metronidazole
82
Drugs causing retinopathy?
1. Chloroquine 2. Quinine
83
Beta blocker overdose Rx?
1. If bradycardic then atropine 2. In resistant cases glucagon may be used
84
Drugs causing photosensitivity?
1. Thiazides 2. Tetracyclines, sulphonamides, ciprofloxacin 3. Amiodarone 4. NSAIDs e.g. piroxicam 5. Psoralens 6. Sulphonylureas
85
Aspirin OD bloods?
Mixed respiratory alkalosis and metabolic acidosis
86
Aspirin OD features?
1. Hyperventilation (centrally stimulated respiration) 2. Tinnitus 3. Sweating, pyrexia 4. N&V 5. Hyper and hypoglycaemia 6. Seizures 7. Coma
87
Salicylate OD Rx?
1. General = ABC, charcoal 2. Urinary alkalinisation with IV sodium bicarbonate = enhances elimination of aspirin in urine 3. Haemodialysis
88
Indications for haemodialysis in salicylate OD?
1. Serum concentration >700mg/L 2. Metabolic acidosis resistant to treatment 3. Acute renal failure 4. Pulmonary oedema 5. Seizures 6. Coma
89
Cocaine MOA?
Blocks uptake of DA, NA, and HT
90
Cocaine effect classification?
1. Cardiovascular = coronary artery spasm, tachycardia and bradycardia, hypertension, QRS widening and QT prolongation, aortic dissection 2. Neurological = seizures, mydriasis, hypertonia, hyperreflexia 3. Psychiatric = agitation, psychosis, hallucinations 4. Others = ischaemic colitis, hyperthermia, metabolic acidosis, rhabdomyolysis
91
Cocaine toxicity Rx?
1. Benzodiazepines 2. Chest pain = Benzodiazepines + GTN, if MI develops then primary PCI 3. HTN = Benzodiazepines + Sodium nitroprusside
92
When should NAC be given for Paracetamol OD?
1. If staggered overdose or there is doubt over time of the paracetamol ingestion, regardless of the plasma paracetamol concentration 2. If the plasma paracetamol concentration is on or above a single treatment line joining points of 100 mg/L at 4 hours and 15 mg/L at 15 hours, regardless of risk factors of hepatotoxicity
93
NAC administration mushkies?
1. Infused over 1 hour to reduce risk of s/e 2. Commonly causes an anaphylactoid reaction (non-IgE mediated mast cell release) --> stop infusion and restart at a slower rate
94
King's College Hospital criteria for liver transplantation (paracetamol liver failure)?
1. Arterial pH < 7.3, 24 hours after ingestion 2. Or all of the following = PT > 100s, Cr > 300, Grade III/IV encephalopathy
95
Staggered OD definition?
If all the tablets were not taken within 1 hour
96
When should plasma paracetamol levels be taken?
Minimum of 4 hours after ingestion
97
Aspirin MOA?
Aspirin works by blocking the action of both cyclooxygenase-1 and 2. Cyclooxygenase is responsible for prostaglandin, prostacyclin and thromboxane synthesis. The blocking of thromboxane A2 formation in platelets reduces the ability of platelets to aggregate which has lead to the widespread use of low-dose aspirin in cardiovascular disease.
98
Aspirin indication?
First line for all pts with IHD
99
Aspirin potentiates?
1. Oral hypoglycaemics 2. Warfarin 3. Steroids
100
First line Rx following ischaemic stroke and PAD?
Clopidogrel (although NICE still states aspirin + dipyridamole)
101
Most common s/e of sildafenil?
Headache
102
Drug-induced thrombocytopenia?
1. Quinine 2. Abciximab 3. NSAIDs 4. Furosemide 5. Abx = penicillins, sulphonamides, rifampicin 6. Anticonvulsants = carbamazepine, valproate 7. Heparin
103
Adrenaline indications?
Anaphylaxis and cardiac arrest
104
Anaphylaxis adrenaline dose?
0.5ml 1:1000 IM
105
Cardiac arrest adrenaline dose?
1. 10ml 1:10,000 IV 2. 1ml 1:1000 IV
106
Management of accidental injection of adrenaline?
Local infiltration of phentolamine
107
Adrenaline actions on alpha adrenergic receptors?
1. Inhibits insulin secretion by pancreas 2. Stimulates glycogenolysis in the liver and muscle 3. Stimulates glycolysis in myscle
108
Adrenaline action on beta adrenergic receptor?
1. Stimulates glucagon secretion in the pancreas 2. Stimulates ACTH 3. Stimulates lipolysis by adipose tissue
109
Drugs causing urinary retention?
1. TCAs = Amitryptiline 2. Anticholinergics = antipsychotics, antihistamines 3. Opioids 4. NSAIDs 5. Disopyramide
110
Opioid OD Rx?
Naloxone
111
Benzodiazepine OD Rx?
1. Majority are managed with supportive care only due to risk of seizures with flumazenil 2. It is generally only used with severe or iatrogenic doses
112
TCA OD Rx?
1. IV bicarbonate may reduce risk of seizures and arrhythmias in severe toxicity 2. Dialysis
113
Lithium OD Rx?
1. Mild-moderate toxicity may respond to volume resuscitation with normal saline 2. Haemodialysis may be needed in severe toxicity 4. Sodium bicarbonate is ometimes used but there is limited evidence to support this. By increasing the alkalinity of the urine it promotes lithium excretion
114
Warfarin OD Rx?
Vitamin K, PCC
115
Heparin OD Rx?
Protamine sulphate
116
BB OD Rx?
1. If bradycardic then atropine 2. In resistant cases glucagon may be used
117
Ethylene glycol OD Rx?
1. Fomepizole first line 2. Ethanol 3. Haemodialysis in refractory cases
118
Methanol OD Rx?
1. Fomepizole or ethanol 2. Haemodialysis
119
Organophosphate poisoning Rx?
1. Atropine 2. Role of pralidoxime unclear
120
Iron OD Rx?
Desferrioxamine
121
Lead OD Rx?
1. Dimercaprol 2. Calcium edetate
122
Cyanide OD Rx?
1. Hydroxocobalamin 2. Combination of amyl nitrite, sodium nitrite and sodium thiosulfate
123
Sulfonylurea side effect?
1. Hypoglycaemic episodes 2. Increased appetite and weight gain 3. SIADH 4. Liver dysfunction (cholestatic)
124
Glitazone s/e?
1. Weight gain 2. Fluid retention 3. Liver dysfunction 4. Fractures
125
Gliptins s/e?
Pancreatitis
126
Features of opioid misuse?
1. Rhinorrhoea 2. Needle track marks 3. Pinpoint pupils 4. Drowsiness 5. Watering eyes 6. Yawning
127
Rx of opioid dependence?
1. Specialist drug dependence clinics/GPSI 2. Maintenance therapy or detoxification 3. Methadone or buprenorphine first line in detox 4. Compliance monitored using urinalysis 5. Detoxification should last up to 4 weeks in an inpatient/residential setting and up to 12 weeks in the community
128
When is diclofenac contraindicated?
1. IHD 2. PAD 3. Cerebrovascular disease 4. Congestive HF This advice does not apply to topical diclofenac
129
Lithium toxicity precipitants?
1. Dehydration 2. Renal failure 3. Drugs = diuretics (esp. thiazides), ACEi, ARBs, NSAIDs, Metronidazole
130
Lithium toxicity features?
1. Coarse tremor (fine tremor seen in therapeutic levels) 2. Hyperreflexia 3. Confusion 4. Polyuria 5. Seizure 6. Coma
131
Mefloquine use?
Prophylaxis and treatment of certain types of malaria
132
Mefloquine mushkies?
1. Nightmares or anxiety may be prodromal of a more serious neuropsychiatric effect 2. Suicide and DSH have been reported 3. Adverse reactions may continue for several months 4. Should not be used in pts with Hx of anxiety, depression, schizophrenia or other psychiatric disorders
133
Which TB medication can cause gout?
Pyrazinamide
134
Which TB medication can cause rash?
Ethambutol
135
Is routine digoxin monitoring required?
No, only in suspected toxicity, which if suspected should be measured 8-12 hours since last dose
136
Amoxicillin s/e?
Rash with infectious mononucleosis
137
Co-amoxiclav s/e?
Cholestasis
138
Flucloxacillin s/e?
Cholestasis (usually develops several weeks after use)
139
Erythromycin s/e?
1. GI upset 2. Prolongs QTi
140
Ciprofloxacin s/e?
1. Lowers seizure threshold 2. Tendonitis
141
Metronidazole s/e?
Reaction following alcohol ingestion
142
Doxycycline s/e?
Photosensitivity
143
Trimethoprim s/e?
1. Rashes, including photosensitivity 2. Pruritis 3. Suppression of haematopoiesis
144
Allopurinol MOA?
Inhibits xanthine oxidase
145
Initiating allopurinol prophylaxis?
1. Commencement of ULT (urate lowering therapy) is best delayed until inflammation has settled as ULT is better discussed when the patient is not in pain 2. Initial dose of 100 mg od, with the dose titrated every few weeks to aim for a serum uric acid of < 300 µmol/l. Lower initial doses should be given if the patient has a reduced eGFR 3. Colchicine cover should be considered when starting allopurinol. NSAIDs can be used if colchicine cannot be tolerated. The BSR guidelines suggest this may need to be continued for 6 months
146
Allopurinol indication?
1. To all patients after first attack of gout 2. Particularly recommended if: >=2 attacks in 12 months, tophi, renal disease, uric acid renal stones, prophylaxis if on cytotoxics or diuretics 3. Pts with Lesch-Nyhan syndrome for life
147
Allopurinol adverse effects?
1. Severe cutaneous adverse reaction (SCAR) 2. DRESS 3. Stevens-Johnson Syndrome
148
Allopurinol indications?
1. Azathioprine = can lead to very high levels of 6-mercaptopurine, a 25% dose must therefore be used if the combination cannot be avoided 2. Cyclophosphamide = reduces renal clearance, therefore may cause marrow toxicity 3. Theophylline = increases plasma conc of theophylline by inhibiting its breakdown
149
What medications can exacerbate HF?
1. Thiazolidinediones e.g. pioglitazone c/i as it causes fluid retention 2. Verapamil = -ve inotropic effect 3. NSAIDs/glucocorticoids = can cause fluid retention 4. Class I antiarryhthmics = fleicanide (negative inotropic and proarryhthmic effect)
150
Metformin renal consideration?
NICE recommend that the dose of metformin should be reviewed if the creatinine is > 130 micromol/l (or eGFR < 45 ml/min) and stopped if the creatinine is > 150 micromol/l (or eGFR < 30 ml/min)
151
Ecstasy (MDMA) poisoning features?
1. Neurological = agitation, anxiety, confusion, ataxia 2. CVS = tachycardia, hypertension 3. Hyponatraemia 4. Hyperthermia 5. Rhabdomyolysis
152
Ecstasy OD management?
1. Supportive 2. Dantrolene may be used for hyperthermia if simple measures fail
153
Amiodarone thyroid dysfunction prevalence?
1 in 6 pts taking amiodarone
154
Amiodarone induced hypothyroidism mushkies?
The pathophysiology of amiodarone-induced hypothyroidism (AIH) is thought to be due to the high iodine content of amiodarone causing a Wolff-Chaikoff effect. Amiodarone may be continued if this is desirable
155
Amiodarone induced thyrotoxicosis types?
1. AIT Type I = Excess iodine-induced thyroid hormone synthesis, goitre present, Rx with carbimazole or potassium perchlorate 2. AIT Type II = Amiodarone-related destructive thyroiditis, goitre absent, Rx with corticosteroids 3. Unlike in AIH, amiodarone should be stopped if possible in patients who develop AIT
156
What is the Wolff-Chaikoff effect?
An autoregulatory phenomenon where thyroxine formation is inhibited due to high levels of circulating iodide
157
Why avoid nitrofurantoin in pts with CKD Stage II or higher?
Significant risk of treatment failure and occurrence of side effects due to drug accumulation
158
Drugs to avoid in renal failure?
1. Abx = tetracyclines, nitrofurantoin 2. NSAIDs 3. Lithium 4. Metformin
159
Quinolone MOA?
Inhibit DNA synthesis (inhibit topoisomerase II (DNA gyrase) and topoisomerase IV) and are bactericidal in nature, e.g. ciprofloxacin and levofloxacin
160
Quinolone adverse effects?
1. Lowers seizure threshold in pts with epilepsy 2. Tendon damage incl. rupture 3. Cartilage damage in animal models (therefore generally avoided in children) 4. Prolongs QTi
161
Quinolone contraindications?
1. Avoided in pregnant/breastfeeding women 2. Avoid in G6PD
162
Macrolide MOA?
Post-transcriptional methylation of the 23S bacterial ribosomal RNA. Macrolides act by inhibiting bacterial protein synthesis by blocking translocation. If pushed to give an answer they are bacteriostatic in nature, but in reality this depends on the dose and type of organism being treated.
163
Macrolide examples?
Erythromycin, clarithromycin, azithromycin
164
Macrolide adverse effects?
1. QT prolongation 2. GI s/e (nausea less common with clarithromycin than erythromycin) 3. Cholestatic jaundice 4. P450 inhibitor 5. Azithromycin associated with hearing loss and tinnitus
165
Macrolide common interaction?
Statins - should be stopped whilst taking a course of macrolides. Macrolides inhibit the cytochrome P450 isoenzyme CYP3A4 that metabolises statins. Taking macrolides concurrently with statins significantly increases the risk of myopathy and rhabdomyolysis
166
Tamoxifen adverse effects?
1. Menstrual disturbance = vaginal bleeding, amenorrhoea 2. Hot flushes = 3% stop taking due to climacteric s/e 3. VTE 4. Endometrial cancer
167
How long is tamoxifen usually used for?
For 5 years following removal of the tumour
168
Sildafenil and stroke?
Contraindication = recent stroke or MI --> NICE recommend waiting 6m
169
ACEi s/e?
Cough and hyperkalaemia
170
Bendroflumethiazide s/e?
1. Gout 2. Hypokalaemia, hyponatraemia 3. Impaired glucose tolerance
171
Calcium channel blocker s/e?
1. Headache 2. Flushing 3. Ankle oedema
172
BB s/e?
1. Bronchospasm (especially in asthmatics) 2. Fatigue 3. Cold peripheries
173
Doxazosin s/e?
Postural hypotension
174
If metformin not tolerated due to GI side effects?
Try a modified release formulation
175
Vancomycin class?
Glycopeptide
176
Tetracycline s/e?
Phototoxicity and IIH
177
Carbamazepine P450 enzyme?
An inducer of the P450 --> increases the metabolism of itself = auto-induction