Respiratory Flashcards
What are the side effects of inhaled corticosteroids
Throat infections, hoarseness
Some counselling points for inhaled corticosteroids
Should have a gradual withdrawal when used for >3 weeks
What are the leukotriene receptor antagonists
Leukotrienes cause bronchoconstriction and inflammation
What is omalizumab
A monoclonal antibody which is directed against free IgE but not bound IgE
Prevents IgE from binding to immune cells which leads to allergen-induced mediator release in allergic asthma
How can NSAIDs irritate asthma
They can increase leukotriene production
What has the greatest impact in the management of patients with COPD
Smoking cessation and flu vaccinations
Who is CAP most common in
Males
Elderly
Alcoholics
Chronic disease
What is the aetiology of CAP
60-80% caused by conventional bacteria
Atypical bacteria causes 10-20%
10-20% also caused by viruses
What are the steps in investigating CAP
Confirm diagnosis: CXR, microbiological samples,
Assess severity of disease
Define aetiological agent
Identify complications
What microbiological investigations are involved in diagnosing CAP
- sputum analysis and culture
- immunofluorescence on sputum samples
- blood cultures
- urinary pneumococcal and legionella antigen
Describe the CURB 65 criteria
Confusion (mini mental test score of 8 or less)
Urea >7mmol/L due to infection impairing renal function
Resp rate >30 severe breathlessness
BP: <90/60
Age >65
Each counts for 1 point
What does a CURB65 score of 0 or 1 mean for treatment
Amoxicillin 500mgs qds for 5 days or doxy 200mgs loading then 100mg of
IV amoxicillin 500mg tds if can’t take oral
If penicillin allergy give ciprofloxacin 400mg bd + vancomycin
What treatment do you give someone with a CURB 65 score of 2
Amoxicillin 500mg qds for 7 days + clarithromycin 500mg bd for 7 days or doxycycline 200mg loading then 100mg od
If unable to take oral therapy: benzylpenicillin + iv clarithromycin
If severe allergy penicillin ciprofloxacin 400mg bd + vancomycin
What treatment do you give to someone with CURB 65 >3
- Co amoxiclav 1.2g tds + clarithromycin 500mg bd iv 10 days
- Levofloxacin 500mg bd + vancomycin 1g bd
Treat for 10 days extending to 14-21 for legionella, staphylococcal or gram -ve bacteria
What is tuberculosis
The most important infectious disease in recent world history
9.6M new cases and 1.5 million deaths annually
Most often affects immigrant populations
Mode of action of rifampicin (antimycobacterial)
Inhibits mycobacterial RNA polymerase
Rifampicin 450mg of <50kg or 600mg od >50kg
Is bactericidal
Causes hepatitis, rash, fever, flu syndrome and multiple drug interactions
Mode of action of isoniazid
Poorly understood
- inhibits cell wall mycolic acid synthesis
- associated with hepatitis, peripheral neuropathy and cutaneous hypersensitivity
- has a rapid and bactericidal effect
What is pyrazinamide (antimycobacterial)
Mode of action unknown
Dose of 1.5g od <50kg or 2g od >50kg
- can cause hepatitis, anorexia, flushing, cutaneous hypersensitivity and hyperuricaemia
- plays a key role in sterilising inflammatory tissue
What is ethambutol (antimycobacterial)
Inhibits synthesis of cells wall polysaccharides
Dose 15mg/kg daily
Most important effect is optic neuritis
Moderate bactericidal effect
What is streptomycin (antimycobacterial)
Binds to mycobacterial ribosome (16S rRNA and S12 protein) and inhibits protein synthesis
- must be given parenterally (15mg/kg) and blood levels should be measured in renal impairment
Bactericidal
Side effect: ototoxicity
What are the 2 principles of chemotherapy
- mycobacteria within an infected individual are in different phases of replication
- the mycobacterial population contains naturally occurring resistance mutants
What are the antituberculous regimens
Rifampicin, isoniazid, pyrazinamide and ethambutol given for a 2 month period
Followed by
Rifampicin and isoniazid for 4 months
What is DOT
Directly observed therapies
Use a nurse or surrogate to directly observe all doses being taken
Who is at risk of drug resistant TB
Individuals previously treated for TB
Known contact with a case of drug resistant TB
Acquisition of infection in a country or group with high prevalence of drug resistance
Patients who fail to make a response to adequate conventional treatment
