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When should topical antibiotics be used?
- 2nd line mild acne
- may be used earlier for moderate
- used in combo to prevet resistance
What are the side effects of topical antibiotics?
- possible pseudomembranous colitis
Which antibiotic most commonly causes pseudomembranous colotis?
Topical antibiotics is used in combo with __________________________ for moderate to severe acne.
- benzoyl peroxide
What is the frequency of use for topical antibiotics?
- (Erythromycin& Clindamycin)
What are the preg categories of topical antibiotics?
In what ages can topical antibiotics be used?
When should systemic antibiotics be used?
- moderate to severe acne
- OR if topical treatments were ineffective
- OR is there is backance
- OR risk of scarring/pitting
What is the risk of using systemic antibiotics?
- Increased resistance
- Caution with oral contraceptives
- Other drug interactions
When shoudl you see improvement with systemic antibiotics?
- 6-10 weeks
- full effects: 6 months
What is the MOA of Erythromycin (Macrolide)?
- Binds 50s subunit
- Inhibits translocation step of translation of mRNA to protein
What are the possible interactions of systemic Eryhtromycin?
- Liver Enzyme Inhibitor: can cause an Inc. concentration of 3A4 substrates (diltiazem, digoxin, wafarin)
- QTc prolongation (w/ antiarrythmias, geodon)
What is the MOA of systemic Clindamycin?
- Discrete binding site of 50s subunit from Eryth.
- Inhibits protein synthesis
- Inhibits translocation step
- Inhibits peptidyl tranferase enzyme (inhibits peptide bond formation)
What are the characteristics of resistance for macrolides?
- Efflux of drug pump
- Drug Induces methylase enzyme synthesis (drug cant bind to subunit)
- Baacteria produces esterases (inactivate the drug)
What are the characteristics of resistance for clindamycin?
- Not sequestered by same pumps as Macrolides
- Not a methylase inducer (are ineffective w/ bacteris where methylases are always "on")
What is the MOA of Tetracylines?
- inhibits translation of mRNA to protein
- Binds to 30s subunit
- Blocks binding of tRNA to "A" site (inhibits elongation)
What are the side effects of the tetracycline class?
- GI- alters normal flora
- Binds Ca+2 ions (tooth/bone)
- Hepatic/Renal toxicity
What is the dosing of Tetracycline?
- 250-500mg BID (dec. when lesions begin to clear up)
- 1-2hrs before meals OR 4-6hrs after meals
What are the side effects for tetracycline?
- tooth discolorization
- vaginal infections
What are the drug interactions of Tetracycline?
- Avoid dairy, antacids, iron
- use caution with 3A4 substrates
What is recommended age and Preg category of the tetracycline class?
Which drugs of the tetracycline class has a better potency for gram + bacteria?
- Doxycycline ~2x
- Minocycline ~2-4x
What is the dosing for Doxycycline?
100-200mg Qday, then 50mg once improved
What are the side effects of doxycylcine?
- GI upset-- more common than tetracycline
- Gastric Irritation
- (Increased Incidence)
What are the drug interactions of doxycycline?
- Antacids, iron
- 3A4 substrates
- (Not affected by food as much)
What are the side effects of Minocycline?
- Immediate: 100mg daily
- Extended: weight based (70kg- 65mg/day)
What are the side effects of Minocycline?
- Vestibular toxicity
- Skin discoloration
- Drug-induced auto-immune lupus
What are the interactions of minocycline?
separate from antacids, iron, dairy (1-2 hrs b4 OR 4-6 hrs after)
When shoud you use caution with tetracylines? And which one needs dosing adjustments?
- Renal & Hepatic impairment
Which tetracycline causes pseudotumor cerebri? And what is it?
- Intracranial hypertension
3A4 inhibitors will ________________ drug levels of ______ substrates like warfarin, cyclosporine, siltiazem, and simvastatin.
What is the dosing of systemic Erythromycin?
What are the side effects of Erythromycin?
What is the Preg Category of Erythromycin?
When should you use caution when using systemic Eryhtromycin?
What is the dosing of systemic Clindamycin?
What are the side effects of clindamycin?
- GI upset
- Pseudomembranous colitis
What is the Preg Category of clindamycin?
When should you use caution when using systemic Clindamycin?
What is the MOA of Sulfonamides?
- Competitive inhibitor of DHPS
- inhibit folic acid synthesis (hinders synth of DNA purine bases)
- inhibitbition of DNA synthesis
What is the MOA of Sulfametoxazole + Trimetoprim
- SMZ: Competitive Inhibitor of DHPS
- TMP: Competitive Inhibitor of DHFR
- Combo: Bacteriocidal
What are the (4) characteristics of resistance of SMZ + TMP?
- Altered DHPS
- Efflux OR dec. absorption of drug
- alternatice folic acid synthesis pathway
- Inc. PABA synthesis
What is the normal dosing of SMZ + TMP?
800mg/160mg (DS) BID
What are the side effects of SMZ+TMP?
- Kidney injury (crsytalluria)
What are the interactions with SMZ+TMP?
- 2C8/9 substrates (warfarin, phenytoin)
- cyclosporine (inc. nephrotoxicity)
What is the Preg Category of SMZ+TMP?
C, D if at term
When should you avoid using SMZ+TMP?
- Glc-6-phosphate dehydrogenase deficiency
- ---can cause hemolytic anemia
What are the hormones used in hormonal therapy for treatment of acne?
- Ethinyl Estradiol & Norgestimate
- (Estrogen & Progesterone)
What is the MOA for hormonal therapy of acne?
- Inc. Sex Hormone Binding Globulin
- Dec. Free Testosterone (Androgen)
- ---Dec. Sebum Production
- ---Dec. Hyperkeratinization
What are the side effect of hormonal therapy?
- estrogens promote clotting
- risk of MI and stroke inc. in high-risk patients
- breast cancer risk
When are oral contraceptives used to treat acne?
for moderate to severe acne in females
What are the side effects of oral contraceptives?
- weight gain
- breast tenderness
- breakthrough bleeding
- inc. risk of thromboembolic disease
When can you see full effects of OC's?
2-4 months (musts take at same time Qday)
What are the contraindiciations of OCs?
- Thromboemblonic disease
- Heavy Smoking
- Endometrial or Breast Cancer
- Pregnancy (X)
What are the drug interactions of OCs?
When do you use caution with OCs?