Abx Groups Flashcards
Natural Penicillins
- PCN G
- PCN V
- Beta lactamase susceptible
Beta lactamase resistant Penicillins
Antistaphylococcal PCNs
- Nafcillin
- Oxacillin
- Dicloxacillin
- Methicillin
- Bulky side chain protects from beta lactamase, but limits them to gram positive only
Extended Spectrum Penicillins
- Amoxicillin/Clavulanate
- Ampicillin/Sulbactam
- Pipercillin/Tazobactam
- Ticarcillin/Tazobactam
- Increased gram negative coverage due to smaller molecule size
Monobactam
Aztreonam
- only active against aerobic gram neg rods, IV only, CNS penetrance, no cross reactivity with PCN allergy
- dose adjust in renal failure
- beta lactamase sensitive
Carbapenems
- Doripenem
- Ertapenem
- Imipinem/Cilastin - lowered seizure threshold
- Meropenem
- Resistant to beta lactamases, can be hydrolyzed by ESBLs and carbapenemases, IV only, all cover pseudomonas except ertapenem
Macrolides
- Erythromycin - absorption problem, don’t take with food, GI upset, inhibits CYP3A4, used for pertussis, chlamydia
- Clarithromycin
- Azithromycin - Zpack, super overused, slow half life, single dose chlamydia tx
- Bind to 50s subunit, resistance via efflux, reduced permeability, modification of ribosomal binding site
- D-test - indicates macrolide inducible resistance to Clindamycin by inducible methylase, alters binding site
- prolongs QT segment
Ketolides
- Telithrolide
- same MOA as macrolides, less resistance, CYP450 inhibitor so drug induced hepatitis
First Gen Cephalosporins
- Cefazolin
- Cefalexin
- Renal excretion, no CNS penetrance, active against gram pos cocci (but not enterococci)
- used for MSSA infection, surgical wound prevention in PCN allergic patients, pan-susceptible E. Coli UTI
Second Gen Cephalosporins
- Cefaclor - serum sickness rxn, not used clinically
- Cefoxime - IV only, used for perioperative wound prevention and prophylaxis in operations on GI or GU (anaerobes)
- Cefuroxime - used PO for outpatient resp infections
- Cefotetan - IV only, used for perioperative wound prevention and prophylaxis in operations on GI or GU (anaerobes), disulfuram-like rxn w alcohol, hypothrombinemia, bleeding
Third Gen Cephalosporins
- Ceftriaxone - IV, CNS penetrance, biliary excretion, overused in ER
- Cefdinir - oral outpatient, red poop
- Cefotaxime - IV, CNS penetrance
- Ceftazidime - antipseudomonal, similar to Aztreonam
- Cefixime - previously used for gonorrhea
Fourth Gen Cephalosporins
- Cefipime
- excellent gram neg coverage, increased activity against MDR strep pneumo, drug of choice in neutropenic fever, sepsis in sickle cell patients
Fifth Gen Cephalosporins
- Ceftaroline
- Ceftolazone/Tazobactam
- use with ID oversight
- only cephs w enterococcal activity
Cell Wall Inhibitors
- Vancomycin
- Televancin - same MOA, less toxicity than Vanc
- Daptomycin - inserts tail into cell membrane
- Fosfomycin - enolpyruvate transferase inhibitor
- Bacitracin - topical for nose and butthole MRSA, inhibits bactoprenols
Tetracyclines
- Doxycyclin - interacts w phenytoin
- Demeclocyclin - also inhibits action of ADH at collecting duct
- Tetracyclin
- Tigecyclin - very broad spectrum, use w ID, pseudomonas and proteus only resistant bugs
- Minocyclin
- reversible binding to 30s subunit, take with food but not with dairy, antacids, or metal cations, teratogenic
Lincosamides
- Clindamycin
- Same MOA as macrolides (50s), good for anaerobes, penetrates abscesses and pus
- resistance by mutation of binding site, methylase (induced or constitutive) checked with D test
- tastes like shit
Streptogramins
- Quinipristine/ Dalfopristin (Synercid)
- block transpeptidase on 50s and translocation at 23s
- Cover PCN resistant gram pos except E. faecalis, no gram neg coverage
- inhibits CYP3A4, interacts w warfarin, diazepam, NNRTIs, cyclosporine
Chloramphenicol
- binds 50s
- inactivated by liver glucuronyl transferase
- Grey baby syndrome
- inhibits metabolism of phenytoin, tolbutamide, chlorpropamide, and warfarin
Oxalidinones
- Linezolid
- prevents formation of entire ribosome complex
- no cross resistance
- used for VRE
- reversible and mild hematologic toxicities: thrombocytopenia, anemia, neutropenia
- also optic/peripheral neuropathy and serotonin syndrome if given w SSRIs
Aminoglycosides
- Gentamicin - naive pseudomonas,
- Tobramycin - naive pseudomonas, inhaled form for CF
- Neomycin - too toxic for IV
- Kanamycin
- Amikacin - backup if genta or tobra resistant
- Streptomycin
- aerobic gram neg bacilli, use in systemic gram neg infections like intra abdominal infections or complicated UTI, no penetration for abscesses
- synergistic with cell wall drugs, bind 30s
- nephrotoxic, ototoxic w trough levels less than 2mcg/mL
SABAs
- Albuterol
- Levalbuterol - L-isomer of albuterol, indicated only for patients with documented ventricular arrhythmia w albuterol. Much more expensive.
- Rescuers - If used more than 2 days/week, consider increasing controller therapy
- Beta 2 agonists (activate Gs, increase cAMP, decrease MLCK)
- Use with spacer
LABAs
- Salmeterol
- Formoterol
- Indicaterol - only once daily LABA, only approved for COPD
- Terbutaline - IV, can also be used in premature labor
- Controllers, mono therapy contraindicated for asthma and COPD
- Should only be used in asthma as an adjuvant to ICSs, step down if possible
Inhaled Anticholinergics
- Ipratropium Bromide (SAAB)
- Tiotropium (LAAB)
- MOA: block acetylcholine, decrease cGMP, cause bronchodilator and decreased mucus production
- Rescuers, greater role in COPD
Calcium affecting
- Magnesium Sulfate
- CCB by competitive inhibition for divalent cationic sites
- Side effects: nausea, vomiting, hypotension (bonus w normal saline to prevent), in toxicity decreased deep tendon reflex and rapid development of pulmonary edema
Phosphodiesterase Inhibitors
- Theophylline - MOA: inhibiting PDE increases cAMP in adrenal medulla, promotes release of epinephrine, causes brochodilation
- can help as add-on for some patients, but limited due to side effects, drug interactions, narrow therapeutic window, unpredictable metabolism
- Roflumilast - PDEI that reduces inflammation but does not bronchodilate
- selectively inhibits PDE4, use only in severe COPD
- Controllers
Inhaled Corticosteroids
- Beclomethasone
- Budesonide
- Fluticasone
- Triamcinolone
- Controllers, reduce airway inflammation , maximal response requires treatment for up to 8 weeks
- prolonged use can increase risk of secondary infection, oral thrush if mouth isn’t rinsed
- primary treatment for status asthmatic us or acute episodes, but acute broncos past relief requires oral steroids
Leukotriene Modifiers
- Zafirlukast
- Montelukast (Singulair)
- These two are leukotriene receptor antagonists (LRTAs) of LTD4 receptors
- Zileuton- 5-lipoxygenase inhibitor, prevents leukotriene formation
- Controllers, decrease airway edema, constriction and inflammation
- Depression and suicide black box warnings
Mast cell actors
- Cromolyn Sodium - stabilizes plasma membranes of mast cells and eosinophils, preventing degranulation and release of histamine, leukotrienes, other substances
- Omalizumab - inhibits IgE binding to mast cells and eosinophils, only indicated in step 5 or 6, anaphylaxis risk
- Controllers
Oral absorbable Sulfonamide drugs
- Sulfisoxazole
- Sulfamethoxazole
- Sulfadoxine/Pyrimethamine
- Sulfamethoxazole/Trimethoprim - p. Jirovecii prophylaxis and tx, toxoplasmosis, prostatitis, good activity against community acquired MRSA
- displace bilirubin from albumin, pancytopenia, hemolytic anemia in G6PD deficiency, crystallization in urinary tract, photosensitivity, rash, SJS, hypersensitivity rxns that look autoimmune
Oral non-absorbable Sulfonamide drug
- Sulfasalazine
- anti inflammatory that is only locally absorbed in but and doesn’t reach systemic levels, used in IBD
Topical Sulfonamide Drugs
- Sulfacetamide - eye drops for pink eye and chlamydia trachomatis
- Silver Sulfadiazine - topical abx used extensively in burn unit
Imidazoles
- Ketoconazole - can treat endogenous Cushing’s syndrome
- Miconazole
- Clotrimazole
- Block CYP450 dependent ergosterol precursor production
- Drug interaction major issue: compete w other drugs if CYP450 inhibitors given
Triazoles
- Fluconazole - most frequent for skin, genital, soft tissue, oral, and esophageal candida
- Voriconazole - most teratogenic, must use contraceptives if on drug, QT prolongation, transient visual or auditory hallucinations
- Itraconazole - major hepatic toxicity can occur, can cause CHF in patients with pre existing LV dysfunction
- Block CYP450 dependent ergosterol precursor production
- Drug interaction major issue: compete w other drugs if CYP450 inhibitors given
Other TB tx
- Cycloserine - D-ala analogue, “psych-serine”
- Para-aminosalicylic acid (PAS) - PABA analogue, MOA Unknown, first TB treatment
- Dapsone - PABA analogue, competitively inhibits dihydropterate synthetase (like sulfas), used in inflammatory dz, severe hemolysis in G6PD deficiency
- Clofazimine - orphan drug, red-black skin, crystals in GI, liver, LNs
- Bedaquiline - inhibits ATP synthase, 5 fold increased risk of all cause death, QT prolongation
- Pretomanid - experimental, similar to metronidazole, inhibits mycolic acid, protein synthesis, generates NO that augments killing
Oral antifungals
- Amphotericin B - nephrotoxic it’s major problem: hypokalemia, hypomagnesia, RTA causing NAGMA, anemia from low EPO
- Flucytosine - fungal cytosine delaminates converts to 5-FU, which blocks thymidylate synthetase, halting DNA production, used w Ampho B
- Caspofungin - an echinocandin, prevents cross linkage of chitin with glucans (glucan synthestase), IV only, no CNS penetrance, increases tacrolimus levels, metabolized in liver
- Griseofulvin - take with fatty food, inhibits micro tubule formation, disrupts mitotic spindle, deposits in precursors or keratin producing cells
- Terbinafine - inhibits squealing epoxidase, blocking ergosterol synthesis
Topical Antifungals
- Naftifine
- Butenafine
- Nystatin - swish and swallow
- Tavaborole - onchomycosis
TB Primary use
- Rifampin
- Isoniazid - Inhibits mycolic acid synthesis, metabolized by NAT2, fast/slow acetylators, can cause hypersensitivity syndromes, methemoglobinemia, peripheral neuritis and neurotoxicity du to pyridoxine deficiency
- Pyrazinamide - activated by acidic conditions in edge of TB cavity, disrupts cell membrane, accumulates in lung epithelial lining fluid, fast/slow absorbers, can precipitate gout
- Ethambutol - inhibits arabinosoyl transferase III, loss of red green vision
- Streptomycin
- All associated with hepatotoxicity
Rifamycins
- Rifampin - strong post abx effect, must be taken on empty stomach, many drug interactions (induces CYP450), poor CNS penetrance, orange body fluids
- Rifapentine
- Rifabutin
- Macrolide abx, enter acid fast bacillus in a concentration dependent manner and bind the beta subunit of DNA dependent RNA polymerase
Mucolytics
- Guaifenisin (Mucinex, Mucinex D) - increases respiratory hydration, requires patient to drink lots of water
- Acetylcysteine - Mucolytic effect related to sulfhydryl group, which reduces disulfide linkages in mucus and lowers viscosity
Cough Suppressants
- Dextromethorphan - SSRI and NMDA blocker at high doses
- Codeine - unpredictable metabolism
- Hydrocodeine - unpredictable metabolism
- These three suppress cough reflex at medullary cough center
- Benzonatate (Tessalon Pearls) - topical anesthetic action on respiratory stretch receptors
Intranasal Corticosteroids
- Beclomethazone (Beconase)
- Budesonide (Rhinocort)
- Ciclesonide (Omnaris)
- Fluticasone (Flonase)
- Mometasone (Nasonex)
- Triamciclone (Nasacort)
- Similar side effect profile to systemic corticosteroids, but much lower risk: adrenal suppression, delayed wound healing, nasal septal perforation, increased intra ocular pressure
Intranasal Antihistamine
- Aselastine - Astelin - 40% bioavailability, fecal elimination
- Olopatadine - Patanase
- Systemic side effects lessened
Systemic Decongestants
- Phenylephrine (Sudafed PE)
- Pseudoephedrine (Sudafed) - can be converted to meth
- Combination D products
- alpha adrenergic agonists
- Side effects of CV stimulation, CNS stimulation, dizziness, headache, anorexia
Topical decongestants
- Phenylephrine (Neo-Synephrine)
- Naphazoline (Privine)
- Tetrahydrozoline (Tyzine)
- Use limited to less than 3 days to prevent rebound congestion
Drugs in C. Difficile
- Vancomycin
- Metronidazole
- Fidoxamicin
Dihydrofolate Reductase Inhibitors
- Trimethoprim
- Pyrimethamine (Daraprim)
- complexed to sulfonamides for sequential inhibition
- Daraprim for toxoplasmosis
Floroquinolones
- Nalidixic Acid - unable to reach sufficient serum or tissue levels for systemic infections, used in minor UTI
- Ciprofloxacin - urinary FQ
- Ofloxacin - urinary FQ
- Levofloxacin - respiratory FQ
- Moxifloxacin - resistant pathogens
- inhibit topoisomerase 2 and topoisomerase
- good absorption but avoid cationic meds and such
- renal excretion except Moxifloxacin
- black box: tendons fucked, esp if old, renal failure, steroid use
- QT interval prolonged
- teratogenic
Topical Antibiotics
- Mupirocin - product of P. Flourescens, inactivated staphylococcal isoleucyl tRNA synthetase, big problems with resistance
- Polymixin B - cationic detergent, disrupts lipid membrane, bind and inactivate endotoxin, gram neg only
- Polymixin E - cationic detergent, disrupts lipid membrane, bind and inactivate endotoxin, gram neg only
- Fidoxomicin - non absorbed macrolide, bonds sigma factor in c. Diff required for RNA polymerase binding to promoter
First gen oral antihistamine
- Diphenhydramine - Benadryl
- Doxylamine - Unisom - OTC sleep aid
- Hydroxyzine - Vistaril - pruritis aid
- Promethazine - Phenergan
- Meclizine - AntiVert - motion sickness and vertigo
- MOA: Competitive H1 receptor antagonism
- May cause Anticholinergic syndrome
- Cross BBB and cause sedation
2nd gen antihistamines
- Cetrizine - Zyrtec, Zyrtec D
- Fexofenadine - Allegra, Allegra D
- Loratidine - Claritin, Claritin D
- Desloratidine - Clarinex, Clarinex D
- MOA: H1 receptor competitive antagonism
- Do not cross BBB as much as 1st gen, safer for use in elderly
- “D” products are combined with decongestant Pseudoephedrine
Urinary antiseptic
- Nitrofurantoin
- absorbed from GI tract and immediately excreted into the urine
- some MOA involving highly reactive intermediates
- contraindicated in renal failure, can cause hemolytic anemia and neuropathy in G6PD deficiency
- cumulative risk of irreversible pulmonary fibrosis (regular PFTs needed)
Oxidative damage
- Metronidazole
- prodrug w active metabolites that cause oxidative damage
- anaerobic or parasitic infections
- accumulates in liver failure
- disulfiram like rxn
- first line for C. difficile colitis, giardiasis, entamoeba histolytica, trichomoniasis
- cumulative neurotoxicity can manifest w seizures and peripheral neuropathy