Clinical Pharmacology Flashcards

Question

what class of antiarrhythmia is Flecanide?

Answer 1

Flecainide is a Vaughan Williams class 1c antiarrhythmic.

Answer 2

It slows conduction of the action potential by acting as a potent sodium channel blocker (specifically the Nav1.5 sodium channels). This may be reflected by widening of the QRS complex and prolongation of the PR interval.

Answer 3

atrial fibrillation SVT associated with accessory pathway e.g. Wolf-Parkinson-White syndrome

Answer 4

post myocardial infarction structural heart disease: e.g. heart failure sinus node dysfunction; second-degree or greater AV block atrial flutter

Answer 5

negatively inotropic bradycardia proarrhythmic oral paraesthesia visual disturbances

Answer 6

Mnemonic - Class 1 antiarrhythmics (Na channel blockers); 'Double Quarter Pounder, Lettuce Mayo, Fries Please' 1a - Disopyramide, Quinidine, and Procainamide 1b - Lidocaine and Mexiletine 1c - Flecainide and Propafenone

Answer 7

Quinolones are a group of antibiotics which work by inhibiting DNA synthesis and are bactericidal in nature. Examples include: ciprofloxacin levofloxacin Mechanism of action inhibit topoisomerase II (DNA gyrase) and topoisomerase IV

Answer 8

Adverse effects lower seizure threshold in patients with epilepsy tendon damage (including rupture) - the risk is increased in patients also taking steroids cartilage damage has been demonstrated in animal models and for this reason quinolones are generally avoided (but not necessarily contraindicated) in children lengthens QT interval Contraindications Quinolones should generally be avoided in women who are pregnant or breastfeeding avoid in G6PD

Answer 9

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

Answer 10

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 phosphatase that activates various transcription factors in T cells

Answer 11

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

Answer 12

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

Answer 13

local infiltration of phentolamine

Answer 14

responsible for the fight or flight response released by the adrenal glands acts on α 1 and 2, β 1 and 2 receptors acts on β 2 receptors in skeletal muscle vessels-causing vasodilation increases cardiac output and total peripheral resistance causes vasoconstriction in the skin and kidneys causing a narrow pulse pressure

Answer 15

inhibits insulin secretion by the pancreas stimulates glycogenolysis in the liver and muscle stimulates glycolysis in muscle

Answer 16

stimulates glucagon secretion in the pancreas stimulates ACTH stimulates lipolysis by adipose tissue

Answer 17

Phentolamine, a short acting alpha blocker, may be used in this situation. It is normally used mainly to control blood pressure during surgical resection of phaeochromocytoma

Answer 18

Features bradycardia hypotension heart failure syncope Management if bradycardic then atropine in resistant cases glucagon may be used Haemodialysis is not effective in beta-blocker overdose

Answer 19

primary and secondary immunodeficiency idiopathic thrombocytopenic purpura myasthenia gravis Guillain-Barre syndrome Kawasaki disease toxic epidermal necrolysis pneumonitis induced by CMV following transplantation low serum IgG levels following haematopoietic stem cell transplant for malignancy dermatomyositis chronic inflammatory demyelinating polyradiculopathy

Answer 20

Monoclonal antibodies have an increasing role in medicine. They are manufactured by a technique called somatic cell hybridization. This involves the fusion of myeloma cells with spleen cells from a mouse that has been immunized with the desired antigen. The resulting fused cells are termed a hybridoma and act as a 'factory' for producing monoclonal antibodies.

Answer 21

**infliximab (anti-TNF):** used in rheumatoid arthritis and Crohn's **rituximab (anti-CD20):** used in non-Hodgkin's lymphoma and rheumatoid arthritis **cetuximab (epidermal growth factor receptor antagonist): **used in metastatic colorectal cancer and head and neck cancer **trastuzumab (HER2/neu receptor antagonist):** used in metastatic breast cancer **alemtuzumab (anti-CD52)**: used in chronic lymphocytic leukaemia **abciximab (glycoprotein IIb/IIIa receptor antagonist): **prevention of ischaemic events in patients undergoing percutaneous coronary interventions **OKT3 (anti-CD3):** used to prevent organ rejection****

Answer 22

Ciprofloxacin

Answer 23

Arterial pH < 7.3, 24 hours after ingestion or all of the following: prothrombin time > 100 seconds creatinine > 300 µmol/l grade III or IV encephalopathy

Answer 24

Lithium range = 0.4 - 1.0 mmol/l take 12 hrs post-dose Ciclosporin trough levels immediately before dose Digoxin at least 6 hrs post-dose Phenytoin levels do not need to be monitored routinely but trough levels, immediately before dose should be checked if: adjustment of phenytoin dose suspected toxicity detection of non-adherence to the prescribed medication

Answer 25

aspirin penicillins NSAIDs opiates

Answer 26

Promotes gastric emptying. Erythromycin, a macrolide antibiotic, acts as a motilin receptor agonist in the stomach. Motilin is a hormone that increases gastrointestinal motility and stimulates gastric emptying, which is beneficial in conditions like gastroparesis where there is delayed gastric emptying.

Answer 27

prolongation of the QT interval gastrointestinal side-effects are common. Nausea is less common with clarithromycin than erythromycin cholestatic jaundice: risk may be reduced if erythromycin stearate is used P450 inhibitor (see below) azithromycin is associated with hearing loss and tinnitus

Answer 28

Macrolides inhibit the cytochrome P450 isoenzyme CYP3A4 that metabolises statins. Taking macrolides concurrently with statins significantly increases the risk of myopathy and rhabdomyolysis.

Answer 29

Aminophylline is a bronchodilator used in the management of symptoms of asthma and COPD. It works by relaxing the muscles around the airways so that they open up and breathing becomes easier. The action of aminophylline can be reduced by smoking because tobacco smoke induces hepatic enzymes, particularly CYP1A2, which metabolises aminophylline, leading to a decrease in its serum levels and hence reducing its effectiveness.

Answer 30

Oxidising agents, e.g. hydrogen peroxide, sodium hypochlorite (found in household bleach) Strong alkali, e.g. sodium hydroxide, potassium hydroxide (found in dishwasher cleaner, industrial cleaners) -> liquefactive necrosis, more commonly resulting in oesophageal injury Strong acid, e.g. hydrochloric, nitric acid (found in car batteries, WC cleaner) -> coagulative necrosis, more commonly resulting in gastric injury

Answer 31

A-E approach look for airway swelling/compomise, peri-oral oedema Urgent Upper GI surgery referral f signs of perforation Neutralisation of ingested substance should be avoided (the resulting exothermic reaction will release heat and may cause further injury) High dose IV PPI Early endoscopy and risk stratification is important in patients with symptomatic caustic ingestion - Extensive injury on endoscopy should prompt consideration of urgent surgical exploration Asymptomatic ingestion can usually be discharged after a trial of oral fluid and a period of observation

Answer 32

Acute Upper GI ulceration, perforation Upper airway injury and compromise Aspiration pneumonitis Infection Electrolyte disturbance (e.g. hypocalcaemia in hydrofluoric acid ingestion) Chronic Strictures, fistulae, gastric outlet obstruction Upper GI carcinoma (estimated 1000-3000 fold increased risk)

Answer 33

Drug-induced thrombocytopenia (probable immune-mediated) quinine abciximab NSAIDs diuretics: furosemide antibiotics: penicillins, sulphonamides, rifampicin anticonvulsants: carbamazepine, valproate heparin

Answer 34

Adrenaline induces hyperglycemia, hyperlactatemia and hypokalaemia. Because insulin secretion is suppressed by alpha adrenergic stimulation, plasma concentration of insulin remains low. Hyperglycemia is induced by an increase in glucose production caused by an increase in hepatic glycogenolysis and an increase in gluconeogenesis. There is also a marked increase in oxygen consumption. In skeletal muscle, epinephrine increases glycolysis and glycogenolysis, inducing an upsurge in lactate. Muscular lactate serves as a substrate for hepatic neoglucogenesis (Cori cycle).

Answer 35

Heparin-induced thrombocytopaenia - antibodies form against complexes of platelet factor 4 (PF4) and heparin

Answer 36

Pilocarpine is a muscarinic agonist his results in ciliary contraction (contraction of the iris), which will increase aqueous humour outflow, miosis, and accommodation - used in glaucoma

Answer 37

Metformin should be titrated slowly, leave at least 1 week before increasing dose This is because a common side effect of metformin is diarrhoea and this can be worse if it is increased too soon.

Answer 38

more than 35 years old and smoking more than 15 cigarettes/day migraine with aura history of thromboembolic disease or thrombogenic mutation history of stroke or ischaemic heart disease breast feeding < 6 weeks post-partum uncontrolled hypertension current breast cancer major surgery with prolonged immobilisation positive antiphospholipid antibodies (e.g. in SLE)

Answer 39

Drugs to avoid in renal failure antibiotics: tetracycline, nitrofurantoin NSAIDs lithium metformin

Answer 40

most antibiotics including penicillins, cephalosporins, vancomycin, gentamicin, streptomycin digoxin, atenolol methotrexate sulphonylureas furosemide opioids

Answer 41

Drugs which are known to cause impaired glucose tolerance include: thiazides, furosemide (less common) steroids tacrolimus, ciclosporin interferon-alpha nicotinic acid antipsychotics ## Footnote Beta-blockers cause a slight impairment of glucose tolerance. They should also be used with caution in diabetics as they can interfere with the metabolic and autonomic responses to hypoglycaemia

Answer 42

Quinoloes - ciprofloxacin

Clinical Pharmacology Flashcards

(67 cards)