Mastering Antibiotics

Overview of Antibiotics in Pharmacology

• Antibiotics, also known as antibacterials, are used to prevent and treat bacterial infections.
• There are two main categories of antibiotics: bacteriostatic and bactericidal.
• Bacteriostatic antibiotics slow down bacterial growth, while bactericidal antibiotics directly kill bacteria.
• Sulfonamides are bacteriostatic antibiotics that inhibit folate synthesis, causing a deficiency in folic acid and impacting bacterial DNA.
• Examples of sulfonamides include sulfadiazine and sulfamethoxy.
• Fluoroquinolones are bactericidal antibiotics that inhibit DNA synthesis.
• Examples of fluoroquinolones include ciprofloxacin and levofloxacin.
• Penicillins are the most commonly prescribed antibiotics and are bactericidal.
• Penicillins inhibit cell wall synthesis and are classified as beta-lactam antibiotics.
• Penicillins are broad-spectrum antibiotics effective against both gram-positive and gram-negative bacteria.
• Examples of penicillins include penicillin G (administered intravenously) and penicillin V (taken orally).
• Cephalosporins are beta-lactam antibiotics that are chemically related to penicillins and are also bactericidal.
• Monobactams are bactericidal antibiotics that inhibit cell wall synthesis and are also beta-lactams.

Antibiotics and Drug Interactions: Key Facts and Considerations

• Antibiotics can be classified into different categories, including penicillins, cephalosporins, monobactams, carbapenems, tetracyclines, macrolides, and lincosamides.
• Penicillins, cephalosporins, monobactams, and carbapenems are all beta-lactam antibiotics, sharing a common beta-lactam molecular structure.
• Tetracyclines are bacteriostatic antibiotics that inhibit protein synthesis by targeting the 30s ribosomal subunit. They have the broadest antimicrobial spectrum.
• Macrolides and lincosamides are bacteriostatic antibiotics that also inhibit protein synthesis, but they target the 50s ribosomal subunit.
• Antibiotic prophylaxis is required before dental treatment for patients with certain cardiovascular conditions, such as prosthetic heart valves, history of endocarditis, heart transplant with valve dysfunction, or congenital heart problems.
• Patients with compromised immune systems, such as those undergoing organ transplants or cancer therapy, may also require antibiotic prophylaxis before dental treatment.
• Antibiotic prophylaxis is not recommended for dental procedures that are not invasive, such as simple restorative work or root canal therapy.
• Amoxicillin is the first choice for antibiotic prophylaxis, while clindamycin is an alternative for patients with penicillin allergies.
• Ampicillin can be used for non-oral administration, such as intravenous or intramuscular, when oral medications are not an option.
• Antibiotics can have side effects, such as gastrointestinal upset with clindamycin, superinfection with broad-spectrum antibiotics, aplastic anemia with chloramphenicol, and liver damage with tetracycline.
• Drug interactions can occur with antibiotics, such as the cancellation of effects between bactericidal and bacteriostatic drugs, reduced effectiveness of tetracycline with antacids or dairy products, enhanced action of anticoagulants with broad-spectrum antibiotics, and decreased effectiveness of oral contraceptives with antibiotics.
• Antivirals, like acyclovir and valacyclovir, are used to treat herpes infections, while antifungals, like fluconazole and ketoconazole, are used against fungal infections, such as candidiasis.