Final answer:
Penicillin is administered to prevent bacterial endocarditis in people at risk, with specific treatment regimens depending on the individual's circumstances and stage of infection. Additional prophylactic antibiotics may be recommended. Penicillin is also used to treat other conditions such as syphilis.
Step-by-step explanation:
Penicillin is administered to prevent bacterial endocarditis in people at risk depending on their specific circumstances. For individuals with an increased risk for reinfection, the American Heart Association recommends a treatment regimen consisting of benzathine benzylpenicillin every 3 or 4 weeks. Additional prophylactic antibiotic treatment may be recommended based on the patient's age and risk for reinfection.
In the early stage of infection (about 30 days), antibacterial drugs such as amoxicillin and doxycycline are effective. In the later stages, penicillin G, chloramphenicol, or ceftriaxone can be given intravenously.
In cases of infection of prosthetic valves or other foreign bodies, which may be caused by different pathogens, a combination of antibiotics is often used. For example, prosthetic-valve endocarditis is often treated with a combination of vancomycin, rifampin, and gentamicin.
It's important to note that penicillin is also used to treat other conditions such as syphilis, where a single intramuscular injection of long-acting penicillin can cure primary, secondary, or early latent syphilis. Multiple doses may be required for late latent or tertiary syphilis.