PPT Flashcards
How do we use CURB65 to aid management of pneumonia?
CURB65 score of…
0-1 - low risk so consider treatment with oral amoxicillin at home
2 - probable admission and treat with oral amoxicillin or doxycycline
3-5 - admission and manage with IV co-amoxiclav or IV clarithromycin
Why do we manage severe pneumonia with IV co-amoxiclav?
If its severe there is a higher chance of it being an atypical pneumonia - co-amoxiclav has a broader spectrum than amoxicillin
Why is amoxicillin the first line antibiotic for mild pneumonia?
As the most common microorganism is S.pneumonia
What is the risk of cross-reactivity between a cephalosporin and penicillin allergy? Why?
Up to 10%
They are both beta lactase’s
Outline the MOA, main and serious side effects, interactions and contraindications of penicillins?
Interfere with bacterial cell wall synthesis
SE - diarrhoa, n+v, hypersensitivity, thrombocytopenia, agranulocytosis, hepatic and nephritic impairment
Severe SE - severe skin reactions, anaphylaxis, pseudomembranous colitis
Interactions - warfarin, phenindione, methotrexate, acenocoumarol
Contraindications - Hx of allergy to penicillins or cephalosporins
Outline the MOA, main and serious side effects, interactions and contraindications of tetracyclines?
Allosterically bind to 30S prokaryotic ribosomal subunit
SE - angioedema, d+v+n, photosensitivity, HSP, exacerbates SLE, pericarditis
Serious SE - liver and kidney damage, intercranial hypertension
Interactions - warfarin, tretinoin, phenidione, lithium, Ciclosporin and acenocournarol
Contraindication s- pregnancy
Outline the MOA, main and serious side effects, interactions and contraindications of macrolides?
Inhibit protein synthesis by binding 50S ribosomal subunit
SE - reduced appetite, d+n+v, dizziness, hearing impairment, insomnia, pancreatitis, skin reactions, paraesthesia, vasodilation, vision disorders
Contraindications - liver disease and QT prolongation
Outline the MOA, main and serious side effects, interactions and contraindications of cephalosporins?
Bind to penicllin binding protein and interrupt cell wall biosynthesis = bacterial cell lysis
SE - abdo pain, d+n+v, dizziness, eosinophilia, leukopenia, neutropenia, thrombocytopenia, pseudomembranous colitis, skin reactions, vulvovaginal candidiasis
What is antimicrobial stewardship?
An organisational or healthcare-system-wide approach to promoting and monitoring judicious use of antimicrobial to preserve their future effectiveness
What are BTS recommendations for antimicrobial prescribing in pneumonia?
The diagnosis of CAP and the decision to start antibiotics should be reviewed by a senior clinician at the earliest opportunity.
There should be no barrier to discontinuing antibiotics if they are not indicated.
The indication for antibiotics should be clearly documented in the medical notes.
The need for IV antibiotics should be reviewed daily.
De-escalation of therapy, including the switch from intravenous to oral antibiotics, should be
considered as soon as is appropriate, taking into account response to treatment and changing
illness severity.
Strong consideration should be given to narrowing the spectrum of antibiotic therapy when specific patho-gens are identified or when the patient’s condition improves.
Where appropriate, stop dates should be specified for antibiotic prescriptions
What are the principles of antimicrobial prescribing?
Right antibiotic - what organisms could be infecting? What risk factors for resistance does this pt have?
Right pt
Right time - did you obtain cultures before? We’re antibiotics administered within an hour?
Right dose - appropriate for renal/hepatic function?
Right route - are they a candidate for oral treatment?
Least harm - are we choosing the most narrow spectrum and minimum duration and least amount of SE?
What types of healthcare acquired infections does the use of broad spectrum antibiotics predispose to?
C.diff
MRSA
E.coli infections
What antibiotics are typically used for atypical pneumonia?
Macrolide antibiotics
What drug therapy is given in TB?
Isoniazid, rifampin, Pyrazinamide and ethambutol for 2 months
Isoniazid and rifampin for 4 additional months
Why is TB drug therapy given in 2 phases?
Because TB bacteria have different growth rates and are susceptible to different drugs at different stages of their life cycle.
The first phase (intensive phase) typically lasts for 2 months - isoniazid, rifampicin, pyrazinamide, and ethambutol. These drugs are effective against actively dividing TB bacteria and help to rapidly reduce the bacterial load in the body. The intensive phase is important because it can quickly reduce the number of bacteria, reducing the risk of transmission to others.
The second phase (continuation phase), which typically lasts for an additional 4 months. isoniazid and rifampicin, which are effective against dormant TB bacteria that are not actively dividing. The continuation phase is important to ensure that all the TB bacteria in the body are eliminated, reducing the risk of relapse and preventing the development of drug-resistant TB.
By using a combination of drugs in two phases, TB treatment can effectively target both actively dividing and dormant bacteria, leading to a higher cure rate and reduced risk of relapse. It is important to follow the full course of treatment to ensure complete recovery and to prevent the development of drug-resistant TB.
What are the main SE of rifampicin?
Orange urine/tears
Hepatotoxicity
What are drug interactions for rifampicin?
can reduce plasma concentrations of oestrogen in those
taking oral contraceptives and of many other
drugs including warfarin, phenytoin and
sulphonylureas
Inducers and inhibitors of CYP3A4 (inhibitors include protease inhibitors used in HIV, macrolide antibiotics, antifungal, non-hydropyridine CCB) (inducers include anticonvulsants, st joins wort and glitazones)
Whats the moa of isionazid?
It’s a pro-drug activated by catalase–peroxidase activity within the mycobacteria. The active product inhibits enzymes involved in the synthesis of long-chain mycolic acids, which are unique to the cell wall of mycobacteria, and also inhibits enzymes required for nucleic acid synthesis.
Isoniazid is bactericidal against dividing mycobacteria, but bacteriostatic on resting mycobacteri
What are the main SE of isoniazid?
Hepatotoxic
Peripheral neuropathy
Why is Pyrazinamide not used as the sole treatment for TB?
Rapid resists acid develops
