13. Random Flashcards

Question

What causes galactorrhoea 4x What suppresses

Answer 1

Haloperidol Cimetidine Opioid Spirinolactone may cause galactorrhoea. Bromocriptine supresses

Answer 2

intracellular divalent cation, 1 reducing the systemic vascular resistance (vasodilation). 2 It has anticonvulsant properties, bronchodilation, and it reduces hypoxic pulmonary vasoconstriction. 3 It is used in the management of acute severe asthma and should be considered if inhaled bronchodilators have been ineffective. Explain the reduced muscle tone high plasma levels of deep tendon reflexes (not increased). The change in deep tendon reflexes is used to titrate magnesium therapy in pre-eclampsia. Cross - placenta - fetal side effects may be treated using calcium gluconate. Potentiate - effects on non-depolarising muscle relaxants, and smaller doses of relaxant should be given to patients on magnesium.

Answer 3

Acetylcholine receptors consist of five subunits (not seven) and are arranged in a pentameric structure around a central ion channel or ionophore. The subunits are known as α, β, δ and ε (alpha, beta, delta and epsilon) and all receptors contain two α-subunits and one δ, β and ε unit. There is no Ω subunit. In the fetus, γ (gamma) replaces ε. They are found in high concentrations on the crests of the postjunctional folds (not pits). The entrance of ionophore is 4 nm in diameter (not 20 nm).

Answer 4

Gentamicin & aminoglycosides affecting cochlear and vestibular systems, whereas vancomycin mostly affects the cochlear apparatus. Furosemide like other loop diuretics may rarely cause vestibular damage. Minocycline also can infrequently cause vestibular damage. Clopidogrel unlike salicylates is not ototoxic and aciclovir is also not ototoxic.

Answer 5

Monoamine oxidase (MAO) enzymes are present in the mitochondria of most tissues (not cytoplasm) including both central and peripherally located catecholamine secreting nerve endings. They catalyse the inactivation of amines (not formation) by oxidative deamination to aldehyde derivatives. Two distinct types have been identified (not three): type A mainly inactivates (not synthesizes) norepinephrine (or noradrenaline) and 5-hydroxytryptamine, and type B mainly inactivates tryptamine and phenylethylamine. Dopamine and tyramine are inactivated by both enzymes. Both types A and B are found in the liver and brain, and type B predominates in the basal ganglia.

Answer 6

= ([Na+] + [K+] + [Ca2+] + [Mg2+]) - ([Cl-] + [lactate] + [SO42-]

Answer 7

``` Convulsions Supraventricular tachycardia (SVT) and Ventricular tachyarrhythmia (VT). A respiratory alkalosis is typical due to hyperventilation, but metabolic acidosis can occur due to convulsions and hypotension. ``` Hot flushes are not a feature.

Answer 8

Glucocorticoids and steroids, may cause ``` Iatrogenic Cushing's with Thin skin Easy bruising Glucose intolerance and diabetes Hypertension Hypokalaemia Hirsutism Osteoporosis and may result in hypogonadotrophic hypogonadism (hence amenorrhoea). ``` Glucocorticoid therapy may also be associated with aseptic necrosis of the femoral

Answer 9

Midazolam is ionised (water soluble) in solution at pH 4, changes to an unionised (lipid soluble) ring structure at physiological pH. Atracurium consists of 10 stereoisomers, as it has 4 chiral centres. Cisatracurium is the most potent. Atracurium does not display tautomerism. The solubility of thiopental depends on transformation from the keto to the enol form, which occurs in an alkaline solution. Morphine also displays the keto-enol transformation. Nitrous oxide exists in two forms, with dynamic interchange between N+=N-=O and N-≡N+-O.

Answer 10

Loperamide is a synthetic piperidine derivative used to treat diarrhoea. It is a substrate for the P-glycoprotein efflux transporter in the gut wall causing antiperistalsis. Its oral bioavailability is only 0.3%. Morphine is well absorbed by the gastrointestinal (GI) tract but has relatively low oral bioavailability of 30-40% because of first pass metabolism by the liver. The aminoglycoside neomycin is poorly absorbed by the GI tract but can be given orally to alter gut flora in a patient with hepatic encephalopathy. Paracetamol absorption is negligible in the stomach because of low pH (pKa value is 9.5). In the alkaline environment of the small intestine the absorption of paracetamol is very rapid and complete. Oral bioavailability approaches 100%. Sodium cromoglycate is a mast cell stabiliser and is poorly absorbed by the GI tract having a bioavailabilty of 1-2%.

Answer 11

Aspirin like most NSAIDs acts through inhibition of cyclo-oxygenase. Rofecoxib is a selective COX-II inhibitor and is used specifically as it is not associated with the inhibition of COX-I responsible for the production of mucosal protection in the stomach. Clopidogrel is an ADP receptor antagonist and responsible for inhibtion of platelet aggregation through this route. Losartan is an angiotensin antagonist. Domperidone is a dopamine antagonist.

Answer 12

Warfarin and sulphonamides are highly bound to plasma proteins and aspirin displaces them which increases their unbound proportion and potentiates their effect. Asprin can cause hypoglycaemia by potentiating the effect of chlorpropamide. Diazepam and the tetracyclines are unaffected by aspirin.

Answer 13

numerous receptors including dopamine receptors antagonistic at muscarinic, 5-hydroxytryptamine (5-HT), histamine and alpha (1 and 2) adrenoceptors. Its sedative effects are known as neurolepsy which are accompanied by a reduction in motor activity and muscle tone. The EEG shows a pattern characteristic of sleep and this sedative side effect limits chlorpromazine's use as an antiemetic. Side effects include extrapyramidal symptoms such as dystonias, akathisia and tardive dyskinesia, but it does not commonly cause parkinsonian features (rigidity, akinesia and tremor). Chlorpromazine has a local anaesthetic effect by stabilising cell membranes and reducing the tendency of nerves to depolarise. It is extensively metabolised in the liver and many metabolites may be detected in the urine up to 18 months after administration.

Answer 14

Hydralazine is metabolised by N-acetyl transferase and slow acetylators are more likely to develop side effects, particularly drug-induced systemic lupus erythematosus. Suxamethonium is metabolised by cholinesterase and variation in metabolic characterisitics may produce prolonged neuromuscular paralysis.

Answer 15

Drugs which inhibit dihydrofolate reductase include: Methotrexate Pyrimethamine Trimethoprim. Drugs which interfere with the absorption and storage of folate include: Phenytoin Primidone Oral contraceptives. Tetracyclines, vitamin B12 and ibuprofen do not interfere with folic acid metabolism.

Answer 16

Carbonic anhydrase is a zinc containing enzyme which is found in ``` Erythrocytes (not plasma) The nephron Pulmonary endothelium Gut Pancreas Cardiac and skeletal muscle. ``` Seven isoenzymes have been identified to date. Isoenzyme IV is found in the in the brush border of the proximal convoluted tubule and isoenzyme II is found within the luminal cells. It is inhibited by acetazolamide, which is used as prophylaxis against mountain sickness and in the management of glaucoma. Spironolactone is an aldosterone antagonist and is classed as a potassium sparing diuretic.

Answer 17

1 cisplation ethacyrnic acid gent / aminogly fruse

Answer 18

movement sub across conc gradient requires expend energy - affect hypoxia temp active tport system characterised max tport rate