13.1 Antibiotics Flashcards
What is the first line management of a lower UTI?
Nitrofurantoin or Trimethoprim, 3 day course in (non-pregnant) women, 7 day course in men
What is the drug class of nitrofurantoin?
Nitrofuran
What is the mechanism of action of nitrofurantoin?
Affects protein synthesis
Taken up by bacterial cell and reduced to reactive intermediates by nitrofuran reductase
Reactive metabolites bind to bacterial ribosomes, inhibits bacterial enzyme synthesis of DNA, RNA, cell protein synthesis and other metabolic enzymes
Why does nitrofurantoin concentrate in the urine?
50% of PO is excreted in the urine in an unchanged form.
Nitrofurantoin concentrates in the urine
When should you give Nitrofurantoin?
Lower UTI
UTI prophylaxis
What are the adverse effects of nitrofurantoin?
- Brown urine
- Pulmonary fibrosis
- Hepatic disorders
- Peripheral neuropathy
- Haematological - anaemia, thrombocytopenia
When should you not give nitrofurantoin?
Renal impairment eGFR <45ml/min
Pregnancy at term- neonatal haemolysis
When should trimethoprim be used?
Lower UTI
UTI prophylaxis
What is the mechanism of trimethoprim?
Folate antagonist
Inhibits bacterial dihydrofolate reductase
What does dihydrofolate reductase do?
Production of tetrahydrofolate
Necessary for production of bacterial nucleic acids RNA, DNA and proteins
When should trimethoprim not be given?
Pregnancy
High risk of teratogenicity in first trimester
What can cause myelosuppression?
Severe bone marrow suppression (myelosuppression)
What is co-trimoxazole?
Trimethoprim + sulfamethoxazole
What is the drug class of gentamicin?
Aminoglycoside
What are some examples of aminoglycosides?
Gentamicin
Vancomycin
Streptomycin
Neomycin
Tobramycin
