Respiratory ( 5% ) Flashcards
- Salbutamol
- a. Is useful for prophylaxis of asthma.
- b. Results in decreased cAMP in smooth muscle cells.
- c. Has no significant beta side effects
- d. May cause arrythmias in excessive doses
- e. Is as effective orally as inhaled.
d. May cause arrythmias in excessive doses
- a. Is useful for symptomatic relief of asthma only, due to its short DOA
- b. Results in increased cAMP in smooth muscle cells (B2 = Gs).
- c. Has significant beta side effects including tachycardia, arrhythmia, tremor, and hypokalaemia
- e. Is less effective orally as inhaled due to significant first pass metabolism
- The beta 2 sympathomimetic with the longest duration of action is
- a. Salbutamol
- b. salmeterol
- c. Sotalol
- d. Terbutaline
- e. Isoproteronol
b. salmeterol
- 12 hours*
- Salbutamol is 4 hours*
- Sotalol is a beta-blocker and type III (K blocker) antiarrhythmic*
- Isoproteneronol is a non-selective beta agonist*
- Terbutaline beta-agonist (reliever) up to 6 hours*
- All of the following cause direct bronchodilation EXCEPT:
- a. Atropine
- b. Adrenaline
- c. Salbutamol
- d. Theophylline
- e. Disodium cromoglycate
e. Disodium cromoglycate
Mast-cell stabiliser
Others are all either beta agonists or anticholinergics
- Salbutamol may cause all of the following EXCEPT:
- a. Hyperkalemia.
- b. A low pO2 initially
- c. Skeletal muscle tremor
- d. Nervousness
- e. Weakness
a. Hyperkalemia.
Causes Hypokalemia
Can initially cause a low pO2 as its vasodilatory effects can create a V/Q mismatch, where under-ventilated portions of the lung being getting perfused (as the hypoxic vasoconstriction is overcome)
- Which of the following has been shown to inhibit both mediator release from lung tissue and relax respiratory smooth muscle tissue?
- a. Beta agonists
- b. Disodium cromoglycate
- c. Histamine H1 antagonists
- d. Histamine H2 antagonists
- e. Corticosteroids
a. Beta agonists
- Salbutamol
- a. Stimulates adenylyl cyclase in smooth muscle cells
- b. Rarely causes tachycardia
- c. Is a beta 1 selective adrenoceptor agonist.
- d. Should be used with caution in hyperkalaemic patients.
- e. Rarely results in tolerance through high use
e. Rarely results in tolerance through high use
Tachyphylaxis has not been shown
- a. Stimulates cAMP in smooth muscle cells (B2 is a Gs receptor)
- M3 stimulates adenylyl cyclase (Gq) - MOA of ipratropium)
- b. often causes tachycardia
- c. Is a beta 2 selective adrenoceptor agonist.
- d. Should be used with caution in hypokalaemic patients.
- Used as a treatment for hyperkalaemic patients
- Which of the following relaxes the respiratory smooth muscle and inhibits release of bronchoconstricting mediators from mast cells?
- a. Disodium cromoglycate
- b. Beta agonists
- c. Corticosteroids
- d. Ipratropium bromide
- e. Histamine H1 antagonists
b. Beta agonists
- The following side effects typically occur with beta agonists EXCEPT:
- a. Skeletal muscle tremor
- b. Initial decrease in PaO2
- c. Urinary retention.
- d. Weakness
- e. Tachycardia
c. Urinary retention.
Although note that it physiologically could (SNA -> contracts internal urethral sphincter. No role in urination normally, only exists to prevent retrograde ejaculation. But could still theoretically cause retention)
To add to Nicks note above - there is a single case report of urinary retention in a child receiving oral salbutamol, that I could find.
- ipratropium
- a. effects as good as beta agonist
- b. effects last up to 4 hours
- c. half life is 1 hour.
- d. well absorbed.
b. effects last up to 4-5 hours.
(same as salbutamol)
- a. effects not as good as beta agonist -
- Generally less effective, as the M3 receptors play a varying role in bronchoconstriciton in different people, so there is a range of effects. Useful as an adjunctive treatment however.
- c. half life is 2 hours.
- d. Poorly absorbed - quaternary amine, so minimal systemic effects
- Regarding ipratropium bromide
- a. Peak onset is 10min post inhalation
- b. Gives rise to tolerance
- c. Has CNS effects
- d. May precipitate narrow angle glaucoma
a. Peak onset is 10min post inhalation
- c. Has CNS effects*
- d. May precipitate narrow angle glaucoma*
I feel a) is most correct. c) was given as the anser. Another piss-poor question. Main message is that anticholinergic effects of inhaled antimuscarinics are uncommon because the drugs are poorly absorbed into systemic circulation (recall they are quaternary amines and hence highly polar). CNS effects such as headache are uncommon, as is acute angle glaucoma. C is listed as correct answer but given its wording, D is better. Furthermore, quaternary amines can’t cross BBB, making CNS effects even less likely
Other questions note that peak onset is in 10min, and there are a range from 1-20min given, so a) is probably the answer
Onset is 20min, with a peak at 60min.
- Regarding ipratropium
- a. It can cause severe effects which last for 4 hours
- b. It causes miosis.
- c. It is well absorbed orally.
- d. It inhibits mast cells.
- e. It readily enters the CNS.
a. It can cause severe effects which last for 4 hours.
Unusual wording, as is generally less effective than SABAs. May cause severe effects if vagal hyperactivity is a main cause of the patient’s bronchoconstriction (implicated in non-atopic asthma)
- b. It causes Mydriasis (anticholingergic)
- c. It is poorly orally absorbed
- d. It does not inhibit mast cells.
- Mast cells are activated by antigen, not vagus nerve
- Salbutamol does have an anti-mast cell effect however
- e. It does not enters the CNS easily, as it is highly charged
- Ipratropium bromide is useful in the treatment of asthma because it
- a. Inhibits phosphodiesterase
- b. Stimulates beta 2 receptor
- c. Inhibits the release of mast cell mediators
- d. Stimulates cholinergic receptors
- e. None of the above
e. None of the above
Salbutamol stimulates B2
Theophylline inhibits phosphodiesterase
Salbutamol inhibits release of mast cell mediators (or at least has an effect on them)
Ipratropium antagonises M3 receptors
- Ipratropium
- a. Causes miosis
- b. Is well absorbed orally
- c. Inhibits mast cells
- d. Readily enters CNS
- e. Onset of effect within 10 minutes
e. Onset of effect within 10 minutes
Nick had 10min onset in his notes, ERexam says 15min, wiki stats 15-30min, and another paper states 20min, iMeducate states 3-5min (changed from 1-3min as per them),so I am not sure the expected description of onset. Another question had ‘10min peak onset’ which was listed as wrong. Onset 1-20min, peak about 60min is probably the takeaway, and be aware the range might be slightly off, but other options are probably more wrong.
- a. Causes mydriasis (anticholinergic)
- b. Is poorly absorbed orally
- c. Inhibits mast cells - beta agonists do this
- d. Does not easily enters CNS
- The use of steroids in asthma
- a. Inhibits the phospholipase C pathway
- b. Does not suppress the adrenocortical axis if used long term.
- c. Inhibits the formation of catecholamines.
- d. Inhibits the formation of prostaglandins and leukotrienes
- e. Are useful in acute attacks.
d. Inhibits the formation of prostaglandins and leukotrienes
- b. Can suppress the adrenocortical axis if used long term - hence the need for a slow taper
- e. Are not particularly useful in acute attacks.
- Oral steroids used for severe acute asthma but in general inhaled corticosteroids are a preventer medication -> D is a better answer
- Need to keep a general rather than ‘ED’ mindset for this.
- With regard to theophylline, which is INCORRECT?
- a. Oral bioavailability is approximately 96%
- b. Changes in intermittent dosing results in a new steady state within 1-2 days
- c. It is mainly eliminated unchanged in urine
- d. Its volume of distribution is approximately 0.5L/kg lean body weight
- e. IV boluses may cause convulsions or cardiac arrythmias
c. It is mainly eliminated unchanged in urine
85-90% hepatic metabolism
