Discovered in 1928, penicillin revolutionized medicine by treating bacterial infections. It works by disrupting cell wall synthesis, causing bacteria to rupture. Today, it remains vital for strep throat, syphilis, and pneumococcal infections.
This beta-lactam antibiotic targets peptidoglycan in bacterial walls, weakening them. Effective against gram-positive bacteria like Streptococcus, it’s less effective against gram-negative strains due to their outer membrane.
Penicillin treats tonsillitis, rheumatic fever, and dental infections. Prophylactic use prevents endocarditis in high-risk patients. Always complete the prescribed course to avoid resistance.
Available as oral tablets (250mg–500mg), IV injections, or slow-release forms. Dosage depends on infection type—single large doses for syphilis, 10-day courses for strep throat.
Mild reactions include diarrhea and rash. Severe allergies may cause anaphylaxis—swelling or difficulty breathing require immediate epinephrine and medical help.
Inform doctors of any penicillin allergy history. Avoid if mononucleosis is suspected due to rash risk. Use with caution in kidney disease patients.
Derivatives like amoxicillin and ampicillin broaden coverage. Methicillin-resistant strains (MRSA) require alternative antibiotics due to evolved resistance mechanisms.
Store oral penicillin at room temperature, away from moisture. IV solutions are light-sensitive—follow hospital protocols. Never use expired antibiotics.
Probenecid delays penicillin excretion, increasing effectiveness. Contraceptives may have reduced efficacy—use backup methods during treatment.
Mass production in WWII saved countless lives. Overuse led to resistant strains, emphasizing the need for responsible antibiotic prescribing practices globally.
Liquid formulations ease dosing for children. Dosage is weight-based. Never share antibiotics between siblings without pediatrician approval.
Unmetabolized penicillin enters waterways via excretion. Proper disposal of unused medication helps reduce ecological impact and resistance spread.
Penicillin effectively treats strep throat, syphilis, and pneumococcal pneumonia. It’s also used for dental abscesses and preventing rheumatic fever recurrence.
Symptoms often improve within 24–48 hours. Complete the full prescribed course (usually 10 days) to eradicate bacteria and prevent resistance.
No—cross-reactivity is common. Alternatives like macrolides (e.g., azithromycin) are safer for penicillin-allergic patients.
IV or IM penicillin ensures higher bioavailability for severe infections (e.g., endocarditis). Bypassing the gut also avoids stomach acid degradation.
No direct interactions, but live vaccines (e.g., typhoid) may be less effective during antibiotic use. Consult your doctor for timing guidance.
Yes, it’s Category B—considered safe as it doesn’t cross the placenta significantly. Preferred for treating syphilis in pregnant women to prevent fetal harm.
Acidic foods (citrus, tomatoes) may decrease effectiveness. Take oral doses 1 hour before or 2 hours after meals unless directed otherwise.
Culture and sensitivity tests identify effective antibiotics. Zones of inhibition on agar plates measure bacterial response to penicillin derivatives.
Veterinary formulations exist—never self-prescribe. Incorrect dosing in animals can cause toxicity or worsen resistant infections.
Its 1940s debut drastically reduced WWII wound fatalities and made previously deadly infections treatable, ushering in the antibiotic era.