Dermatology
Antimicrobial Drugs
Built from Dermatology, 5th Edition

What’s inside
17 sections · 182 slides
Overview
- Scope of this topic
Principles of Antibacterial Therapy
How physicians choose among hundreds of available antibiotics
- Choosing an antibiotic
- The antibiotic selection pathway
- Bacteriostatic versus bactericidal drugs
- Bacteriostatic versus bactericidal drugs.
- Sites of action of antibacterial drugs
Topical Antibacterials for Acne and Rosacea
Drugs applied directly to skin, combining antibacterial and anti-inflammatory effects
- Why use topical antibacterial agents
- Azelaic acid and benzoyl peroxide
- Topical clindamycin and erythromycin
- Topical tetracyclines, sulfacetamide, metronidazole, dapsone
- Topical antibacterials used for acne vulgaris and rosacea.
- Topical antibacterials used for acne vulgaris and rosacea. (continued)
- Topical antibacterials used for acne vulgaris and rosacea. - continued
- Topical antibacterials used for acne vulgaris and rosacea. - continued (continued)
- Topical antibacterials used for acne vulgaris and rosacea. - continued
- Topical antibacterials used for acne vulgaris and rosacea. - continued (continued)
- Topical antibacterials used for acne vulgaris and rosacea. - continued
- Topical antibacterials used for acne vulgaris and rosacea. - continued (continued)
- Topical antibacterials used for acne vulgaris and rosacea. - continued (continued)
- Indications for topical acne antibacterials
- Dosing, contraindications, and interactions
- Side effects and use in pregnancy
Topical Antibacterials for Superficial Skin Infections
Agents used to treat and prevent impetigo and other shallow bacterial infections
- Mupirocin, retapamulin, and ozenoxacin
- Neomycin, gentamicin, bacitracin, polymyxin B
- Topical antibacterial agents used for superficial skin infections.
- Topical antibacterial agents used for superficial skin infections. - continued
- Topical antibacterial agents used for superficial skin infections. - continued
- Topical antibacterial agents used for superficial skin infections. - continued
- Indications: impetigo and staph decolonization
- Side effects of superficial-infection agents
- Allergic contact dermatitis from a topical antibiotic
- Pregnancy and lactation
Other Topical Antibacterial Agents
Fusidic acid, iodoquinol, and the burn-wound agents mafenide and silver sulfadiazine
- Fusidic acid and iodoquinol
- Mafenide acetate and silver sulfadiazine for burns
- Localized argyria from silver sulfadiazine cream
- Why systemic antibiotics need extra care
- Sites of action of different classes of systemic antibacterial drugs.
Penicillins
The original beta-lactam antibiotics, still first-line for several skin infections
- How penicillins kill bacteria
- Mechanism of beta-lactam and glycopeptide antibiotics
- Penicillin subclasses and their coverage
- Overcoming bacterial beta-lactamase resistance
- Indications for penicillins
- Oral dosages of commonly used penicillins.
- Penicillin allergy and skin testing
- Major side effects of penicillins
- Drug eruptions from beta-lactam antibiotics
- Interactions and pregnancy
Cephalosporins
Beta-lactam relatives of penicillin, grouped into five generations by spectrum
- Mechanism and generations of cephalosporins
- Different classes of cephalosporins and routes of administration.
- Different classes of cephalosporins and routes of administration. (continued)
- Different classes of cephalosporins and routes of administration. (continued)
- Different classes of cephalosporins and routes of administration. (continued)
- Different classes of cephalosporins and routes of administration. (continued)
- Indications for cephalosporins
- Dosages of commonly prescribed cephalosporins.
- Contraindications and major side effects
- Interactions and use in pregnancy
Sulfonamides and Co-trimoxazole
Drugs that starve bacteria of folic acid, the building block for their DNA
- How sulfonamides block bacterial growth
- Mechanism of sulfonamides and trimethoprim
- Co-trimoxazole: a two-step blockade
- Indications and dosing
- Contraindications, side effects, interactions
- Pregnancy and lactation
Macrolides
Erythromycin, clarithromycin, and azithromycin - protein-synthesis blockers with anti-inflammatory bonus effects
- Mechanism and spectrum of macrolides
- Indications for macrolides
- Dosages of commonly used macrolides.
- Dosages of commonly used macrolides. - continued
- Side effects and interactions
- Pregnancy and lactation
Tetracyclines
Doxycycline, minocycline, and relatives - workhorses for acne, rosacea, and tick-borne infections
- Mechanism and spectrum of tetracyclines
- Indications for tetracyclines
- Dosages and routes of administration of the tetracyclines.
- Dosages and routes of administration of the tetracyclines. (continued)
- Dosages and routes of administration of the tetracyclines. - continued
- Dosages and routes of administration of the tetracyclines. - continued (continued)
- Dosages and routes of administration of the tetracyclines. - continued
- Dosages and routes of administration of the tetracyclines. - continued (continued)
- Contraindications and dosing notes
- Minocycline skin and mucosal pigmentation
- Minocycline pigmentation of skin and scars
- Other major side effects of tetracyclines
- Interactions and pregnancy
- Mechanism, spectrum, and indications
- Dosing, side effects, interactions, pregnancy
Quinolones
Fast-acting drugs that jam bacterial DNA-copying machinery
- How quinolones kill bacteria
- Quinolones.
- Quinolones. (continued)
- Quinolone generations broaden coverage
- Indications and dosing
- Contraindications and major side effects
- Interactions and pregnancy
- Mechanism, indications, and dosing
- Side effects, interactions, and pregnancy
Other Agents for Gram-Positive Skin Infections
Reserve drugs for serious staphylococcal and streptococcal infections, including MRSA
- Oxazolidinones: linezolid and tedizolid
- Glycopeptides, lipoglycopeptides, and daptomycin
- Other antibacterial agents used in Gram-positive skin infections.
- Other antibacterial agents used in Gram-positive skin infections. (continued)
- Other antibacterial agents used in Gram-positive skin infections. - continued
- Other antibacterial agents used in Gram-positive skin infections. - continued (continued)
- Other antibacterial agents used in Gram-positive skin infections. - continued
- Other antibacterial agents used in Gram-positive skin infections. - continued (continued)
- Other antibacterial agents used in Gram-positive skin infections. - continued
- Other antibacterial agents used in Gram-positive skin infections. - continued (continued)
- Other antibacterial agents used in Gram-positive skin infections. - continued (continued)
- Other antibacterial agents used in Gram-positive skin infections. - continued (continued)
Antifungal Agents: Overview and Mechanisms
How each antifungal drug class attacks the fungal cell wall, membrane, or DNA
- When topical versus systemic antifungals are used
- Sites of action of antifungal drugs
- Ergosterol synthesis pathway
- Mechanism of action of antifungal drugs.
- Mechanism of action of antifungal drugs. (continued)
- Mechanism of action of antifungal drugs. (continued)
- Four major classes of antifungal drugs
- Fungistatic, fungicidal, and anti-inflammatory effects
Topical Antifungal Agents
First-line treatment for most localized ringworm, yeast, and yeast-related skin conditions
- Topical azoles
- Allylamines, benzylamines, and polyenes
- Ciclopirox, tavaborole, and older topical agents
- Topical antifungal agents.
- Topical antifungal agents. (continued)
- Topical antifungal agents. (continued)
- Topical antifungal agents. - continued
- Topical antifungal agents. - continued (continued)
- Topical antifungal agents. - continued (continued)
- Dosing of topical antifungal agents
Systemic Antifungal Agents
Drugs for nail, hair, and deep fungal infections that topical therapy cannot reach
- Overview of systemic antifungal choices
- Indications for systemic antifungal agents
- Terbinafine and itraconazole dosing
- Dosing of terbinafine.
- Adult dosing of oral itraconazole.
- Adult dosing of oral itraconazole. (continued)
- Fluconazole and the newer triazoles
- Dosing of oral fluconazole.
- Dosing of oral fluconazole. (continued)
- Dosing of oral fluconazole. - continued
- Dosing of oral fluconazole. - continued (continued)
- Griseofulvin dosing
- Oral dosing of griseofulvin.
- Oral dosing of griseofulvin. - continued
- Oral dosing of griseofulvin. - continued
- Amphotericin B, flucytosine, and the echinocandins
- Contraindications for systemic antifungals
- Side effects: terbinafine and griseofulvin
- Drug-induced subacute cutaneous lupus from oral terbinafine
- Side effects of the systemic azole antifungals
- Side effects of systemic azole antifungal agents
- Accelerated photoaging from chronic voriconazole therapy
- Side effects: amphotericin B, flucytosine, echinocandins
- Interactions: terbinafine and azoles
- Selected drug interactions of systemic azole antifungal agents.
- Selected drug interactions of systemic azole antifungal agents. (continued)
- Selected drug interactions of systemic azole antifungal agents. (continued)
- Selected drug interactions of systemic azole antifungal agents. - continued
- Selected drug interactions of systemic azole antifungal agents. - continued (continued)
- Selected drug interactions of systemic azole antifungal agents. - continued (continued)
- Other systemic antifungal interactions
- Pregnancy and lactation: systemic antifungals
Antiviral Agents
Drugs for herpes simplex, varicella-zoster, and cytomegalovirus infections; antiretrovirals for HIV are covered elsewhere
- Mechanism of antivirals for HSV and VZV
- Mechanisms of topical antivirals
- Topical antiherpetic antiviral agents.
- Topical antiherpetic antiviral agents. - continued
- Topical antiherpetic antiviral agents. - continued
- Topical antiherpetic antiviral agents. - continued
- Indications for topical antivirals
Systemic Antivirals for HSV and VZV
Oral and intravenous acyclovir, valacyclovir, and famciclovir
- Indications for systemic HSV/VZV antivirals
- Comparative susceptibility of herpesviruses to antiviral drugs.
- Formulations of systemic antiviral drugs.
- Suppressive therapy for genital herpes
- Treating chickenpox and shingles
- Contraindications and side effects
- Side effects of systemic antiviral agents commonly used in dermatology.
- Drug interactions of systemic antiviral agents commonly used in dermatology.
- Pregnancy and lactation
- Foscarnet and cidofovir
- CMV-specific antivirals and helicase-primase inhibitors
- Key takeaways
- References
- References (continued)
- References (continued)
- References (continued)
- References (continued)
- References (continued)
- References (continued)
- Dermatology, 5th Edition (2-Volume Set)