INFECTIONS - TETRACYCLINES + QUINOLONES Flashcards
MOA of tetracyclines?
prevents protein syntheiss by binding to 30S subunit of ribosomes.
Are tetracyclines bacterostatic or bactericidal?
Bacteriostatic
What spectrum is tetracyclines?
Broad
What are 4 uses of tetracyclines?
Chlamydia, malaria prophylaxis, Resp tract Infection
Acne, Rosacea
List 7 tetracyclines?
Demeclocyline
Doxycline
Lymecycline
Minocycline
Oxytetracycline
Tetracycline
Tigecycline
What is the 2 indications of doxycycline?
Malaria prophylaxis
Chlamydia
Why is minocycline rarely used?
Due to broader spectrum - more harsh SEs
What is common dose of doxycycline?
200mg OD
What are 5 SEs of tetracyclines?
Benign Intracranial hypertension
Tooth discolouration
Dental hypoplasia
hepatotoxic
photosensitivity
What to do if patient has headache and is on tetracycline?
Stop med
report to doctor
What is a contraindication of using tetracyclines?
Can’t be used in children under 12 years
Which tetracycline is contraindicated in children under 8?
Lymecycline
causes teeth staining + dental hypoplasia
Which tetracycline is caution in children between 8-11 + can be only used for severe acute infections?
Doxycycline
Which tetracycline can ONLY be used in life-threatening infections (rocky mountain spotted fever) in under 8 years old?
Doxycycline
Can tetracyclines be used in pregnancy?
NO avoid
Can tetracyclines be used in renal impairment?
Avoid usually
What tetracycline has high risk of irreversible pigmentation/ LE syndrome?
Minocycline
What are the 2 tetracyclines which can be used in renal impairment (exemptions)?
Doxycycline
Minocycline
Can tetracyclines be used in hepatic impairment?
Avoid
What 6 drug classes interact with tetracyclines to increase hepatotoxicity?
Antibiotics (co-amoxiclav, flucloxacillin, isoniazid)
anti epileptics ( carbamazepine, valproate)
Fluconazole, itraconazole
Methotrexate
Statins
Sulfasalazine
What 2 counselling points to let patients who are taking tetracyclines know?
Avoid sunlight or sun lamps - photosensitivity
Avoid antacids, iron or zinc- - leave 2 hr gap
What 3 things should be avoided or given in 2 hr gap in patients taking tetracyclines?
Antacids , iron, zinc
How long to leave gap when taking antacids, iron or zinc when taking tetracyclines?
2 hr gap
What 3 tetracyclines to avoid drinking milk + to take on empty stomach due to reduced absorption? (DOT)
Demeclocycline
Oxytetracycline
Tetracycline
Which 3 tetracyclines can you have with milk (DLM)?
Doxycycline
Lymecycline
Minocycline
What 3 tetracyclines are used for oesophagitis (ulcers, dysphagia)? (DMT)
Doxycycline
Minocycline
Tetracycline
What is label for tetracycline regarding milk?
Do not take milk, indigestion remedies, meds containing iron or zinc 2 hours before or after you take this medicine.
What advice to give patient taking tetracycline for oesophagitis?
Swallow whole with plenty of fluid sitting or standing.
MOA of quinolones?
Inhibits nucleic acid + DNA synthesis
Bactericidal
What condition to AVOID giving quinolones?
MRSA
Spectrum of quinolones?
Broad
What are 2 uses of quinolones?
RTI
UTI
What is MHRA warning about quinolones and side effects?
Long term irreversible SEs
DO NOT prescribe for non severe infections (not for normal UTIs)
What are 4 drugs in quinolone class?
Ciprofloxacin
Levofloxacin
Moxifloxacin
Ofloxacin
How often to take ciprifloxacin?
BD
What quinolone drug is the most dangerous - increased QT prolongation + life-threatening hepatotoxicity?
Moxifloxacin
What are 5 main SEs of quinolones?
Psychiatric disorders
Arthropathy (in children), aortic aneurysm, antacids reduce absoprtion
Tendon damage
CNS disorders
Heart valve regurgitations, hypersensitivity (QT prolongation too)
Seizures
What abx lowers seizure threshold?
Quinolones
Can quinolones be used in pregnancy?
No - causes joint issues in animal studies
Interaction between quinolones + antacids?
Antacids reduce quinolone absorption.
Give Abx 2 hrs before antacid OR take Abx 4 hours after antacid
What is a risk factor for quinolones since they cause QT prolongation?
Patients with hypokalaemia
What is an MHRA warning regarding heart valve regurgitation when using systemic or inhaled fluoroquinolone + how to counsel patients?
Valve doesn’t close properly - blood leaks out.
Counsel patient on symptoms like oedema, palpitations, dyspnoea.
Who is arthropathy common in?
children/ teenagers
What is arthropathy?
Joint disease
What are the 5 MHRA warnings for quinolones?
Suicidal tendencies
QT prolongation + heart valve regurgitation
Life long threatening SEs
Aortic aneurysm
Tendon damage + Seizures
What 3 patient counselling points to tell patients taking quinolones?
1.Avoid sunlight
2.Reduced absorption - no indigestion meds + no dairy products, iron or zinc 2 hrs before or after taking med.
- Driving - may impair
*(Give MHRA advice sheet too)
dairy + quinolones?
reduces absorption
What does UV radiation do to patients on quinolones
mild rash
Is ciprofloxacin an enzyme inducer or inhibitor?
Inhibitor
What 2 drugs/classes interact with ciprofloxacin to increase seizure risk?
NSAIDs
Theophylline
What anticoagulant increases bleeding when used with quinolones?
Warfarin
What 10 drugs can increase QT prolongation when given with quinolones?
Antispychotic drugs,
Anti-arrhythmic drugs - amiodarone, sotalol
Macrolides Abx
Lithium
SSRIs
Clomipramine
Domperidone
lithium
methadone
5HT1 antagonists - triptans
What condition does hypokalaemia increase risk of?
Torsade de pointes
What 4 drugs/classes can increase risk of hypokalaemia + QT prolongation?
B2 agonists
Corticosteroids
Loop + thiazide diuretics
Theophylline
What tetracylcine does not need to be taken with plenty of fluid while sitting or standing ?
demeocycline
