Correct Answer c chlorothiazide D

Which of the following drugs causes the greatest raise in urinary pH?

• 
  A frusemide
  
• 
  B acetazolamide Correct Answer
  
• 
  C chlorothiazide
  
• 
  D phenobarbitone
  

Explanation

It is apparent within 30min and has its maximal effect at 2hrs. Its effect persists for 12hrsafter a single dose. Drugs that decreases urine PH are ammonium chloride, thiazide diuretics, and methenamine mandelate

Question 2

Regarding fosamax, which of the following best describes it's mechanism of action?
Your answer was not correct

• 
  A Formation of hydroxyappatite crystal Correct Answer
  
• 
  B Increasing calcium resorption
  
• 
  C Decrease in phosphate excretion
  
• 
  D Increasing osteoblast activity Your Answer
  

Explanation

The real mechanism is selective inhibition of bone resorption. Fosomax retards formation and dissolution of hydroxyapetite crystals within and outside of the skeleton.

Question 3

Which of the following drugs does not interact with warfarin?
Your answer was correct

• 
  A Phenobarbitone
  
• 
  B Loop diuretic
  
• 
  C Benzodiazepine Correct Answer
  
• 
  D Cepholosporins
  

Explanation

Phenobarbitone is an enzyme inducer thus increasing metabolism of warfarin which will decrease the INR.

Cephalosporins decrease bacteria in gut that produce vitamin K which will increase the anticoagulant effect of warfarin and increase the INR

Frusemide displaces warfarin from its plasma protein binding site increasing its plasma concentration and anticoagulant effect thus increasing the INR

Question 4

Regarding intracellular signalling, which of the drugs listed below has a different mode of action from the others?
Your answer was correct

• 
  A PTH
  
• 
  B Insulin Correct Answer
  
• 
  C Glucagon
  
• 
  D ACTH
  

Explanation

Insulin mode of action involves tyrosine kinase A. The rest of the drugs involve a secondary mechanism camp

Question 5

Which drug and side effect are incorrectly matched?
Your answer was not correct

• 
  A Sodiumvalpraote and idiosyncratic hepatic toxicity
  
• 
  B Phenytoin and gum hypertrophy Your Answer
  
• 
  C Phenobarbitol and enzyme induction
  
• 
  D Ethosuximate and hirsutism Correct Answer
  

Explanation

Phenytoin causes gum hyperplasia

Question 6

All of the drugs listed produce similar effects except?
Your answer was correct

• 
  A Muscarine
  
• 
  B Acetylcholine
  
• 
  C Hyoscine Correct Answer
  
• 
  D Methacholine
  

Explanation

Hyoscine is the only anticholinergic drug in this group

Question 7

Which of the following drugs can cause hypoprothrombinemia?
Your answer was correct

• 
  A Cefuroxime
  
• 
  B Cefotetan Correct Answer
  
• 
  C Cefazolin
  
• 
  D Cefaclor
  

Explanation

Cephalosporins that contain a methylthiotetrazolegroup (e.g. cefamandole, moxalactam, cefmetazole, cefotetan, cefoperazone) frequently cause hypoprothrobinaemia. Administration of 10mg vitamin K twice weekly can prevent this.

Question 8

Which of the following drugs does not cause constipation?
Your answer was not correct

• 
  A Chlorpromazine Your Answer
  
• 
  B Codeine
  
• 
  C Verapamil
  
• 
  D Digoxin Correct Answer
  
• 
  E Imipramine
  

Explanation

Question 9

Which of the following drugs can cause alopecia?

• 
  A Warfarin
  
• 
  B Heparin Correct Answer
  
• 
  C Verapamil
  
• 
  D Digoxin
  

Explanation

Question 10

Which of the following drugs can causes methaemaglobinemia?

• 
  A lignocaine Your Answer
  
• 
  B prilocaine Correct Answer
  
• 
  C bupivicaine
  
• 
  D benzocaine
  

Explanation

Question 11

Which of the following DOES NOT have its metabolism inhibited by limiting liver blood flow?

• 
  A Propoxyphene
  
• 
  B Verapamil
  
• 
  C Lignocaine Your Answer
  
• 
  D Trimethoprim Correct Answer
  

Explanation

All the drugs listed below (except trimetoprim) have their metabolism inhibited by limiting blood flow. Other drugs with the same problem include: alprenolol, amitriptyline, imipramine, INH, labetalol, lignociane, morphine, propanolol and meperidine

Question 12

Which of the following is the proposed mechanism of N-Acetylcysteine?
Your answer was correct

• 
  A Decreased glutathione availability and release
  
• 
  B Direct binding to NAPQI Correct Answer
  
• 
  C Provision of inorganic nitrate
  
• 
  D Induction of NAPQI back to paracetamol
  

Explanation

NAC prevents NAPQI induced hepatotoxicity when given within 8 hrs of a paracetamol overdose. NAC ameliorates the clinical course of toxicity. Four possible mechanism are described: increased glutathione availability, direct binding to NAPQI, provision of an inorganic substrate and the reduction of NAPQI back to paracetamol.

Note: in Katzung it states "that NAC acts as a glutathione substitute, binding the toxic metabolite as it is being produced"

Question 13

Which drug has a half life of 6 hours?

• 
  A Atenolol Correct Answer
  
• 
  B Aspirin
  
• 
  C Lignocaine
  
• 
  D Adenosine
  

Explanation

Aspirin-3-5hrs, lignociane-2hrs, and adenosine -10s

Question 14

All of the following drugs can cause hyperkalaemia EXCEPT?
Your answer was correct

• 
  A Methyldopa Correct Answer
  
• 
  B Potassium supplement
  
• 
  C Spironolactone
  
• 
  D ACE inhibitor
  

Explanation

Question 15

Regarding allopurinol, which of the following is incorrect?

• 
  A It should be avoided in patients with renal impairment Correct Answer
  
• 
  B It can cuase an acute attack of gout
  
• 
  C It inhibits the metabolism of anicoagulants
  
• 
  D It is used as an antiprotzoal agent Your Answer
  

Explanation

Allopurinol is often the first urate lowering drug used. Its most rational indications are: chronic tophaceous gout, in patients whose 24 urinary uric acid exceeds 600-700mg, when probenocid and sulfinpyrazone cannot be used, recurrent reanl stones and in patients with renal functional impairment.

It causes an acute attack of gout early in treatmentt when urate crystals are being withdrawn from the tissues and plasma levels are below normal. 

It inhibits the metabolism of anticoagulants and probenocid. Chemtherapeutic agents must be reduced by 75%. 

It is used as an antiprotozoal agent

Question 16

Elderly people have reduced hepatic clearance of which of the following drugs?

• 
  A Salicylate
  
• 
  B Warfarin Your Answer
  
• 
  C Prazosin
  
• 
  D Tolbutamide Correct Answer
  

Explanation

Reduced hepatic clearance of certain drugs in the elderly include: alprazolam, barbiturates, diazepam, imipramine, propanolol, quinidine, theophylline, meperidine. No age related difference: ethanol, INH, lignociane, lorazepam, salicylate, warfain, nitrazepam, oxazepam, parzocin

Question 17

Neonates have which of the following?
Your answer was correct

• 
  A An increased total body water Correct Answer
  
• 
  B An increased clearance of drugs by glomerular filtration
  
• 
  C Increased hepatic enzymes
  
• 
  D Increased protein binding
  

Explanation

Neonates have a decreased clearance of drugs by glomerular filtration; decreased hepatic enzyme concentration and a decreased protein binding capacity

Question 18

Which of the following drugs is safest in pregnancy?
Your answer was correct

• 
  A Phenytoin
  
• 
  B Warfarin
  
• 
  C ACE inhibitor
  
• 
  D Heparin Correct Answer
  

Explanation

Thalidomide causes phocomella-shortend or absent long bones and internal malformations. Alcohol causes fetal alcohol syndrome and neurobehavioural abnormalities. Valproate causes neural tube defects, cardiac and limb malformations. Warfarin causes hypoplastic nasal bridge and chondrodysplasia in the 1st trimester, CNS malformations in the 2nd trimester, and an increased risk of bleeding in the 3rd trimester. Enoxaprin can be used in the second trimester but it is not as safe as heparin. Lithium causes Ebstein’s anomaly. Phenytoin causes fetal hydantoin syndrome. Streptomycin causes eighth nerve toxicity

Question 19

Regarding drugs in the elderly, which of the following statements is correct?
Your answer was not correct

• 
  A The elderly have higher serum albumin
  
• 
  B Phase II biotransformation is much poorer Your Answer
  
• 
  C The elderly have an increased lean body mass
  
• 
  D Side effects are proportional to the amount of medication Correct Answer
  

Explanation

The increased effects of the drugs are due to a greater change in pharmocokinetics than pharmacodynamics. There is a greater change is phase one reactions. Phase one reactions are hydration, oxidation and reduction. Phase two reactions are glucuronidation, acetylation, glutathione conjugation, glycine conjugation, sulfate conjugation, methylation, and water conjugation. They have a reduced body mass but an increase in fat percentage. The elderly have a decrease in albumin concentration

Question 20

Which of the following drugs is the safest in pregnancy?
Your answer was correct

• 
  A Heparin Correct Answer
  
• 
  B Lithium
  
• 
  C Phenytoin
  
• 
  D strptomycin
  

Explanation

Thalidomide causes phocomella-shortend or absent long bones and internal malformations. Alcohol causes fetal alcohol syndrome and neurobehavioural abnormalities. Valproate causes neural tube defects, cardiac and limb malformations. Warfarin causes hypoplastic nasal bridge and chondrodysplasia in the 1st trimester, CNS malformations in the 2nd trimester, and an increased risk of bleeding in the 3rd trimester. Enoxaprin can be used in the second trimester but it is not as safe as heparin. Lithium causes Ebstein’s anomaly. Phenytoin causes fetal hydantoin syndrome. Streptomycin causes eighth nerve toxicity

Question 21

In which option is the agent correctly matched with the teratogenic effect?
Your answer was not correct

• 
  A Lithium - Epstein anomaly Correct Answer
  
• 
  B ACE inhibitors - hydronephrosis Your Answer
  
• 
  C Warfarin - neural tube defects
  
• 
  D Sodium valproate - cleft palate
  

Explanation

Thalidomide causes phocomella-shortend or absent long bones and internal malformations. Alcohol causes fetal alcohol syndrome and neurobehavioural abnormalities. Valproate causes neural tube defects, cardiac and limb malformations. Warfarin causes hypoplastic nasal bridge and chondrodysplasia in the 1st trimester, CNS malformations in the 2nd trimester, and an increased risk of bleeding in the 3rd trimester. Enoxaprin can be used in the second trimester but it is not as safe as heparin. Lithium causes Ebstein’s anomaly. Phenytoin causes fetal hydantoin syndrome. Streptomycin causes eighth nerve toxicity

Question 22

Which of the following drugs is safest in pregnancy?
Your answer was correct

• 
  A Heparin Correct Answer
  
• 
  B Warfarin
  
• 
  C Enoxaparin
  
• 
  D Aspirin
  

Explanation

Thalidomide causes phocomella-shortend or absent long bones and internal malformations. Alcohol causes fetal alcohol syndrome and neurobehavioural abnormalities. Valproate causes neural tube defects, cardiac and limb malformations. Warfarin causes hypoplastic nasal bridge and chondrodysplasia in the 1st trimester, CNS malformations in the 2nd trimester, and an increased risk of bleeding in the 3rd trimester. Enoxaprin can be used in the second trimester but it is not as safe as heparin. Lithium causes Ebstein’s anomaly. Phenytoin causes fetal hydantoin syndrome. Streptomycin causes eighth nerve toxicity

Question 23

Regarding drug toxicity and the foetus, which drug-effect pairing is correct
Your answer was correct

• 
  A ACE inhibitors - renal failure Correct Answer
  
• 
  B Thalidomide - neural tube defects
  
• 
  C Alcohol - Ebstein's anomaly
  
• 
  D Sodium valproate - cleft palate
  

Explanation

Thalidomide causes phocomella-shortend or absent long bones and internal malformations. Alcohol causes fetal alcohol syndrome and neurobehavioural abnormalities. Valproate causes neural tube defects, cardiac and limb malformations. Warfarin causes hypoplastic nasal bridge and chondrodysplasia in the 1st trimester; CNS malformations in the 2nd trimester and increased risk of bleeding in the 3rd trimester. Enoxaprin can be used in the second trimester but it is not as safe as heparin. Lithium causes Ebstein’s anomaly. Phenytoin causes fetal hydantoin syndrome. Streptomycin causes eighth nerve toxicity

Question 24

Regarding ethanol metabolism which of the following statements is correct?
Your answer was not correct

• 
  A The MEOS system is the main pathway
  
• 
  B The alcohol dehydrogenase pathway is inducible Your Answer
  
• 
  C It obeys zero order kinetics Correct Answer
  
• 
  D Most alcohol dehydrogenase is found in the stomach
  

Explanation

The main pathway of ethanol metabolism is: alcohol is oxidized by alcohol dehydrogenase to acetaldehyde, which is in turn metabolized by aldehyde dehydrogenase to acetyl CoA. Both steps involve the reduction of NAD to NADH. Metabolism follows zero order kinetic which means that a constant amount is of ethanol is metabolized per unit time. Most of the alcohol dehydrogenase is found in the liver

Question 25

A 30 year old male patient presents with an acute myocardial infarction. Which drug has most likely caused this?
Your answer was correct

• 
  A Alpha-1 effect of cocaine Correct Answer
  
• 
  B Increased adrenalin production due to heroin
  
• 
  C Increased serotonin due to fluoxetine
  
• 
  D Monoamineoxidase inhibition by amphetamine derivative
  

Explanation

The sympathomimetic effects of cocaine are due to the blockade of presynaptic catecholamine re-uptake and can result in vascular dissection, intracranial haemorrhage and acute cardiomyopathy. Vasospasm and endothelial fissuring result in acute coronary syndrome

Question 26

Regarding Marijuana, which of the following statements is correct? 
Your answer was correct

• 
  A It causes miosis
  
• 
  B Hydroponic indoor-grown varieties are not more potent than soil grown
  
• 
  C It causes conjunctival hyperaemia and tachycardia Correct Answer
  
• 
  D Has antipsychotic properties
  

Explanation

Cananbinoids are a powerful psychoactive compound (highly lipid soluble). They act on a protein coupled cannabinoid receptor. THC causes disinhibition of dopamine neurons; mainly by the presynaptic inhibition of GABA neurons in the VTA. The most prominent effects are euphoria and relaxation. Two characteristic physiological sings are increased pulse rate and reddening of the conjunctiva. Pupil sizes do not change

Question 27

Regarding cannabinoids, which of the following statements is correct?
Your answer was correct

• 
  A They produce tachycardia Correct Answer
  
• 
  B They have an antipsychotic action
  
• 
  C They act on a number of non-specific receptors
  
• 
  D They constrict the pupils
  

Explanation

Cananbinoids are a powerful psychoactive compound (highly lipid soluble). They act on a protein coupled cannabinoid receptor. THC causes disinhibition of dopamine neurons, mainly by the presynaptic inhibition of GABA neurons in the VTA. The most prominent effects are euphoria and relaxation. Two characteristic physiological signs are increased pulse rate and reddening of the conjunctiva. Pupil sizes do not change

Question 28

Regarding methanol intoxication, which of the following statements is correct?
Your answer was correct

• 
  A It is partly due to the inhibition of aldehyde dehydrogenase
  
• 
  B It is due to formation of oxalic acid
  
• 
  C It is treated in part with activated charcoal
  
• 
  D It can be treated with 4 methylpyrazole Correct Answer
  

Explanation

Methanol is metabolized in the liver by alcohol dehydrogenase to formaldehyde, which in turn is metabolized by aldehyde dehydrogenase to formic acid. Ethanol/fomepizole competitively inhibits alcohol dehydrogenase so that methanol cannot be metabolized to formaldehyde. GIT decontamination is not recommended

Question 29

Yet another overdose presents to your ED. You examine them and find them to have: blurred vision, urinary retention, dilated pupils and to be very agitated. What have they taken?
Your answer was correct

• 
  A MDMA
  
• 
  B cocaine
  
• 
  C TCA Correct Answer
  
• 
  D Morphine
  

Explanation

TCA overdose cause anticholinergic features which are represented in the question. A good way to remember all of them are: blind as a bat- mydriases, mad as a hatter- delirium, red as a beet-flushing and vasodilatation, dry as a chip- anhydrosis”. Other important features are urinary retention and constipation

Question 30

Regarding cocaine, which statement is incorrect?
Your answer was correct

• 
  A It has local anaesthetic effects
  
• 
  B It inhibits monoamine oxidase Correct Answer
  
• 
  C It blocks uptake of catecholamines
  
• 
  D It has central and peripheral effects
  

Explanation

Cocaine’s sympathomimetic effects are due too the blockade of presynaptic catecholamine re-uptake. It also has a sodium channel blockade effect and local anaesthetic effect. CNS effects results in excitation, seizure and in sever cases hyperthermia

Question 31

Regarding ethylene glycol overdose, which of the following statements is correct?
Your answer was not correct

• 
  A Toxicity is due to polycyclic hydrocarbon ring structure Your Answer
  
• 
  B It causes formic acid crystals in urine
  
• 
  C It causes metabolic alkalosis
  
• 
  D Fomepizole is used as a temporising antidote Correct Answer
  

Explanation

Ethylene glycol toxicity results in a severe metabolic acidosis secondary to the accumulation of glycolic acid and lactate.  Calcium oxalate crystals form in the tissues, including the renal tubules, myocardium, muscles and brain. Hypoclacaemia follows and acute renal failure occurs. Haemodialysis is the definitive treatment. Ethanol and fomepizole is used as a temporizing agent

Question 32

Which opioid analgesic has the longest duartion of action?
Your answer was not correct

• 
  A Morphine
  
• 
  B Codeine
  
• 
  C Buprenorphine Correct Answer
  
• 
  D Methadone Your Answer
  

Explanation

Morphine= 4-5hrs

Codeine= 3-4hrs

Buprenorphine= 4-8hrs

Methadone= 4-6hrs

Question 33

Regarding naloxone, which of the following statements is correct?

• 
  A It has a half life of between 3 and 4 hours
  
• 
  B It has a half life of less than one hour Your Answer
  
• 
  C It has a half life of between 2 and 3 hours
  
• 
  D It has a half life of between 1 and 2 hours Correct Answer
  

Explanation

Naloxone has a half life of 1-2 hours when given by injection and 10 hours when taking via the oral route.  Although naloxone is well absorbed via the oral route it undergoes rapid first pass metabolism. There is no tolerance to the antagonistic action of these agents, nor does withdrawl after chronic administration precipitate an abstinence syndrome

Question 34

Regarding ibuprofen, which of the following statements is correct?
Your answer was not correct

• 
  A It is a strong organic acid
  
• 
  B It has a half life 2 hours Correct Answer
  
• 
  C Urinary excretion of unchanged drug is 20% Your Answer
  
• 
  D Eating the drug with food significantly lowers its bioavailability
  

Explanation

Ibuprofen, like most NSAIDS is absorbed well orally and food does not substantially change its bioavailability. All but one are weak organic acids- nabumetone. Ibuprofen has a half life of 2hrs and is urinary excretion of unchanged drug is <1%. Interestingly, Ibuprofen in doses <600mg QID has analgesic and no anti-inflammatory properties.

Question 35

To which of the following does opioid tolerance not occur?
Your answer was not correct

• 
  A Cough suppression effect
  
• 
  B Hypotensive effect
  
• 
  C Miotic effect Correct Answer
  
• 
  D Respiratory depression effect Your Answer
  

Explanation

Opioid tolerance developes to the analgesic, sedating and respiratory depressant effects. Tolerance also develops to the antidiuretic, emetic, cough suppression and hypotensive effects but not to the miotic, convulsant and constipating actions

Question 36

Regarding Methadone, which of the following is true?