Penicillins

• Beta lactam (cell wall synthesis inhibitors)
• Natural penicillins and synthetic (amoxicillin and piperacillin)

In an attempt to overcome $\beta$-lactamase resistance, penicillins have been combined with a $\beta$-lactamase inhibitors such as: co-amoxiclav (amoxicilliin + clavulanic acid), Tazocin (piperacillin + tazobactam)

Staph resistance is defined by stability to methicillin (IV only equivalent to flucloxacillin)

Antibiotic	Indications	Considerations
Benzylpenicillin	Gram +ve streptococci, meningococcus, diptheria, anthrax, leptospirosis, Lyme disease	Give IV, poor absorption
Phenoxymethylpenicillin	Prophylaxis in some diseases
Ampicillin/[[snippets/Amoxicillin	Amoxicillin]]	Enterobacteria $\downarrow$ activity against Gram +ve, URTI, chest, Otitis media, H. pylori
[[snippets/Co-amoxiclav	Co-amoxiclav]]	Used if resistance to narrower-spectrum antibiotics, chest, pyelonephritis, Cellulitis, [[snippets/Bone
Tazocin	Broad spectrum including: Gram +ve, -ve, Pseudomonas	Tazobactam has $\downarrow$ penetration of blood-brain-barrier. Myelosuppression with prolonged used
Flucloxacillin	$\beta$-lactamase resistant, Staph: skin, [[snippets/Bone	Bone]], post-viral pneumonia