Glycyclines

• Tigecycline is indicated for the treatment of complicated skin and soft tissue, and intra-abdominal infections.
• Tigecycline is a glycylcycline
• Tigecycline has a broad-spectrum activity against multidrug-resistant gram-positive pathogens, some gram-negative organisms, and anaerobic organisms
• Tigecycline exhibits bacteriostatic action by reversibly binding to the 30S ribosomal subunit and inhibiting protein translation.
• Tigecycline does not undergo significant liver metabolism, but it is primarily eliminated via biliary/fecal excretion
• Tigecycline is given via 30- to 60-minute IV infusion every 12 hours
• Tigecycline is associated with nausea, vomiting, photosensitivity, pseudotumor cerebri, discolouration of permanent teeth when used during tooth development, and teratogenicity.
• Glycylcyclines are modified tetracyclines with an extra dimethylglycylamido side chain.
• Administration of tetracyclines is usually topical, or peroral, but tigecycline is IV only.
• If used perorally, tetracyclines should not be taken with food because they readily bind with magnesium, iron, aluminium, and calcium, and the resulting molecule is then unable to be absorbed.
•  tetracyclines are not given to patients on iron and calcium supplements, as well as antacids, which can contain aluminium salts.
• Tetracyclines are broad spectrum, meaning they can target a wide variety of Gram positive and negative bacteria.
• Tetracyclines are used to treat severe acne or community acquired pneumonia.
• Tetracyclines treat intracellular pathogens, such as mycoplasma pneumoniae which causes atypical, or walking pneumonia, and Chlamydia trachomatis which causes chlamydia.
• Both doxycycline and tigecycline are also effective against MRSA
• Tetracyclines are contraindicated  in pregnant or breastfeeding women