DOXYCYCLINE

Dr Sharon Rees @reesprescribe

Day 1: The Tetracycline drug class was derived from soil bacteria ‘actinomycetes’. Tetracycline represents an early example of a broad-spectrum and semi-synthetic antibiotic. Modification to oxytetracycline to increase potency, oral absorption and t½ led to #doxycycline, approved by the in FDA 1967.

Dr Sharon Rees @reesprescribe

Day 2: #doxycycline is active against multiple infections, Gram positive and negative organisms, anaerobes, mycoplasmas, intra-cell chlamydiae, rickettsiae, as well as protozoan parasites. Can be used (where suitable) as oral single agent for methicillin-resistant Staphylococcus aureus.

Dr Sharon Rees @reesprescribe

Day 3: Mode of action. Bacteria have transport systems that admit tetracyclines (TCs), but human cells mostly do not uptake. #doxycycline binds to bacterial ribosome, prevents tRNA binding mRNA, inhibits protein synthesis, cell functions and replication. Predominantly bacteriostatic.

Dr Sharon Rees @reesprescribe

Day 3 (cont): TCs have anti-inflammatory/anti-oxidant properties that may be helpful for inflammatory conditions such as rosacea and periodontitis (low dose). Mechanism possibly via reduced cytokine production, such as TNF-decreased, IL-6, 8 and alpha decreased matrix metalloproteinases so decreased tissue remodel/destruction. Also impaired enzyme production such as phospholipase, so there's decreased prostaglandin synthesis.