Q1

Outline the groups of drugs that might be used in asthma and give an example of each?

  • Sympathomimetics
  • Corticosteroids
  • Muscarinic antagonists
  • Other bronchodilators -magnesium
  • Antihistamines (allergic basis)
  • Methylxanthines
  • Cromolyns
  • Leukotriene inhibitors [antagonists] – montelukast, zafirlukast,zileuton
  • Heliox –changing airflow dynamics
  • Other smooth muscle dilators – ketamine; calcium channel blockers
  • Experimental: IgE monocloncal antibodies – omalizumab

Pass Criteria:

  • Must get 3 bolded groups and one other with one correct drug example per group to pass

Outline the mechanism of action of corticosteroids in asthma?

Corticosteroids do the following:

  • Reduce bronchial reactivity
  • Inhibition of (lymphocytic and eosinophilic) airway mucosal inflammation
  • Increase airway calibre

Pass Criteria:

  • Must get bolded point to pass

 


Q2

Describe the pharmacokinetics of salbutamol?

  • Absorption –complete all routes.
    • Gut fast, resp tract slower
    • Depends on mechanism delivery –  gut 80% with Neb.
  • Metabolism/elimination
    • 50% 1st pass
  • No resp metabolism.
  • T1/2 = 3-6hr – prolonged if resp

Pass Criteria:

  • Good Rapid absorption – all routes
  • Metab 50% + renal

What are the pros and cons of the different routes of delivery?

Prompt: MDI vs nebuliser.

  • Inhaled
    • Inhaler/ spacer:
      • Targeted/ low dose
      • Minimal systemic effects
      • local effects
      • Co-ordination and education required
    • Nebulised
      • Less co-ordination required
      • > dose/systemic effects
      • Noisy/frighten children
      • No benefit in co-ordinated patients
  • Oral
    • Easier in very young/ disabled
    • Longer T1/2
    • > SE profile
    • Big doses, tachyphylaxis – possible increased deaths
  • IV/IM/SC
    • Useful in asthma extremis or other indications
    • Less 1st pass/
    • IV- pain/cost/staff use/high SE profile + high risk pts

Pass Criteria:

  • Grasp of 2 different routes
  • Inhaler/ spacer v Neb v IV minimum.
  • Targetted proven effectiveness inhalers/pacers
  • SE profile: < to >
  • Inh v Neb v Oral v Systemic
  • Co-ordination/delivery in extremis (age or severity) important

 


Q3

What is the mechanism of action of fluoroquinolones?

  • DNA gyrase inhibitor/blocks protein production

Pass Criteria:

  • DNA gyrase inhibition

What are the mechanisms of resistance to fluoroquinolones?

  • Resistance is due to one or more point mutations in the quinolone binding region of the target enzyme or to a change in the permeability of the organism

What are the clinical uses of ciprofloxacin?

  • UTI
  • Bacterial diarrhoea caused by Shigella, Salmonella, toxigenic E coli,Campylobacter
  • Soft tissue, bone, joint, intra-abdominal and respiratory tract infections
  • Treatment against multidrug-resistant organisms (pseudomonas and enterobacter)
  • Prophylaxis and treatment against anthrax
  • Gonococcal infection Chlamydial urethritis or cervicitis
  • TB and atypical mycobacterial infections
  • Eradication of meningococcal carrier state
  • Prophylaxis in neutropenic patients

Pass Criteria: