From the Guidelines
Antimicrobials are medications designed to kill or inhibit the growth of microorganisms and include several major categories, including antibacterial, antiviral, antifungal, and antiparasitic agents, with the most recent and highest quality study 1 emphasizing the importance of proper selection based on the specific pathogen, drug resistance patterns, patient allergies, and infection site.
Types of Antimicrobials
- Antibacterial agents target bacteria and include:
- Beta-lactams (penicillins like amoxicillin, cephalosporins like cefazolin) 1
- Macrolides (azithromycin, erythromycin)
- Fluoroquinolones (ciprofloxacin, levofloxacin)
- Aminoglycosides (gentamicin)
- Tetracyclines (doxycycline)
- Sulfonamides (trimethoprim-sulfamethoxazole)
- Antiviral medications combat viral infections and include:
- Neuraminidase inhibitors (oseltamivir for influenza)
- Nucleoside/nucleotide analogs (acyclovir for herpes, tenofovir for HIV)
- Protease inhibitors (lopinavir for HIV)
- Integrase inhibitors (raltegravir for HIV)
- Antifungal agents target fungal infections and include:
- Azoles (fluconazole, itraconazole) 1
- Polyenes (amphotericin B)
- Echinocandins (caspofungin)
- Allylamines (terbinafine)
- Antiparasitic medications include:
- Antimalarials (chloroquine, artemisinin)
- Antihelminthics (albendazole, ivermectin for worm infections)
- Antiprotozoals (metronidazole for giardiasis, tinidazole for amebiasis)
Mechanisms of Action
Each antimicrobial class works through specific mechanisms, including:
- Antibacterials: disrupting cell wall synthesis or protein production
- Antivirals: interfering with viral replication processes
- Antifungals: targeting fungal cell membranes or cell wall components
- Antiparasitic agents: exploiting metabolic differences between parasites and humans
Selection of Antimicrobials
Proper selection of antimicrobials requires considering factors such as:
- Specific pathogen
- Drug resistance patterns
- Patient allergies
- Infection site
- Local epidemiology and resistance patterns 1
From the FDA Drug Label
Patients should be counseled that antibacterial drugs, including amoxicillin and clavulanate potassium tablets, should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). The different types of anti-microbials mentioned are:
- Antibacterial agents, such as amoxicillin and clavulanate potassium tablets, which treat bacterial infections
- Antiviral agents, which treat viral infections, such as the common cold, but are not explicitly listed in this drug label 2 It can be inferred that there are other types of anti-microbials, including antifungal and antiparasitic agents, but they are not directly mentioned in this drug label.
From the Research
Types of Anti-Microbials
The different types of anti-microbials include:
- Antibacterial agents: such as beta-lactam antibiotics, which include penicillins, cephalosporins, and related compounds 3, 4, 5
- Antiviral agents: fluoroquinolones have been shown to have antiviral activities at clinically achievable concentrations 6
- Antifungal agents: fluoroquinolones have been shown to have antifungal activities, particularly against Candida spp. 6, and quinolines and quinolones have demonstrated antifungal activities 7
- Antiparasitic agents: fluoroquinolones have been shown to have antiparasitic activities 6, and quinolines and quinolones have demonstrated antiparasitic activities 7
Mechanisms of Action
The mechanisms of action of these anti-microbials include:
- Inhibition of type II topoisomerases or inhibition of viral helicases, which maintains the selective toxicity of fluoroquinolones 6
- Inhibition of beta-lactamases, which are enzymes produced by bacteria that hydrolyze the beta-lactam ring of beta-lactam antibiotics 4, 5
- Different mechanisms of action for quinolines and quinolones, which provide high and selective activity against various microorganisms 7
Examples of Anti-Microbials
Examples of anti-microbials include:
- Beta-lactam antibiotics: penicillins, cephalosporins, carbapenems, monobactams, and penems 3, 4, 5
- Fluoroquinolones: which have antibacterial, antiviral, antifungal, and antiparasitic activities 6
- Quinolines and quinolones: which have antibacterial, antifungal, anti-virulent, antiviral, and anti-parasitic activities 7