Antibacterials 6 Flashcards
Clinical applications of trimethoprim
UTI’, bacterial prostatitis and vaginitis
_____________ is an adverse effect of trimethoprim
Neural tube defects because it has antifolate effects (contraindicated in pregnancy)
Cotrimoxazole is a combination of ___________ and ____________ and what does it affect?
Trimethoprim and sulfamethoxazole
Synergistic effect on sequential steps in the tetrahydrofolic acid synthesis
Cotrimoxazole is the DOC for treating _________ but also can be used to treat _________ infections
Uncomplicated UTI’s
Opportunistic infections
Other: upper respiratory, ear and sinus infections
What organisms does metronidazole have activity against?
Anaerobic bacteria;
It is antimicrobial, amebicide and antiprotozoal
MOA of metronidazole
It’s nitro groups undergo reductive bioactivation by ferredoxin → forms cytotoxic groups that interfere with nucleic acid synthesis → damage DNA
__________ (drug) causes DNA damage by cytotoxic products formed by _______
Metronidazole; ferredoxin which reduces the nitro group
Clinical application of metronidazole
- pseudomembranous coliti s
- anaerobic or mix intra abdominal infections
- vaginitis
- brain abscesses
- h. Pylori eradication
What is the route of elimination of metronidazole
Hepatic
Adverse effects of metronidazole
- disulfiram like effect (like 2nd generation cephalosporins: cefamandole, cefotetan)
- headache, dark colored urine, metallic taste
- peripheral neuropathy
- GI irritation
- leukopenia, dizziness, ataxia
- usually not advised to be used in the 1st trimester (no solid evidence)
Polymyxin B has activity against gram _________ bacteria
NEGATIVE;
Gram positive bacteria are resistant to polymyxin B
Polymyxin acts as a _______________ and binds to an inactivates _________
Cationic detergent; ENDOtoxins (unique to gram negative bacteria)
Polymyxin B is mainly used to treat _________
Infected superficial skin lesions so it is given topically
If polymyxin B is given systemically it is extremely _______
Nephrotoxic
What is the use of urinary antiseptics
Use is limited to prophylaxis and treatment because it concentrates in the urine but not systematically
What kind of drug is nitrofurantoin and what is its MOA
Urinary antiseptic
Bacteria reduces the drug in the urine an dleads to reactive intermediates that damage bacterial DNA
Adverse effects of nitrofurantoin
- anorexia, nausea and vomiting
- neuropathies, hemolytic anemia’s
What kind of patients should NOT be given nitrofurantoin to treat a lower UTI?
- G6PD patients because one of the adverse effects is hemolytic anemia
- DO not give to newborns or pregnant women close to term (38 - 42 weeks) but can prescribe before 38 weeks
- patients with significant renal insufficiency
Which one has better oral bioavailbitly: amoxicillin or ampicillin
Amoxicillin
Oral cephalosporins: (3)
Cephalexin, cefaclor, cefixime
What are the “big guns” used for life threatening infections
- vancomycin
- streptogramins
- ceftaroline
Drugs that can treat multi drug resistant
- vanocymin
- daptomycin
- linozelid
- ceftaroline
- quinepristine (streptogramins)
___________ is used for surgical prophylaxis
Cefazolin
Anti staph penicillins are good against β lactamase producting bacteria.
What are the anti staph pencillins
- methicillin
- nafcillin
- dicloxacillin (ORAL ROUTE OF ADMINISTRATION)
- oxicillin
Which drug families are effective against β lactamase producing bacteria?
- anti staph pencillins (mainly gram positive)
- carbapenems (both gram positive and negative)
- aztreonam (gram negative) which is a monobactam
____________ is a β lactam drug that can safely given to pencillin allergic patients dealing with gram __________ infections due to its monocyclic structure
Aztreonam; GRAM NEGATIVE
What drug would you give to a penicillin allergic patient dealing with a gram positive infection?
Macrolides, tetracyclines
Drugs used for prophylaxis of meningitis
- ceftraixone
- ciprofloxacin
- rifampin
