ch. 75 Flashcards
are sulfonamides bacteriocidal or bacteriostatic
bacteriostatic
MOA solfonamides
Sulfonamides are structural analogs of PABA (component of folate) - suppress bacterial growth by inhibiting synthesis of tetrahydrofolate (derivative of folate). On the absence of folate the bacteria cant synthesize DNA, RNA, proteins
Sulfonamides are preferred drugs for
Acute UTIs - Bactrim
how do we make folate?
we dont, get it from our diet. Bacteria makes its own
Treat chlamydia
Azithromycin
doxycycline
used to treat ulcerative collitis
Sulfasalazine
Sulfonamides with rash of any sort or any reaction
stop immediately - high risk SJS
adverse effects of Sulfonamides in newborns
kernicterus
adverse effects of Sulfonamides
blood dyscrasias hypersensitivity photosensitivity avoid prolonged exposure to sunlight - sunburn crystalluria
pt ed on how to take oral sulfonamides
drink 8-10 glasses of water or other non caffeinated fluids per day to decrease risk for crystalluria - can still have caffeine
report rash or tingling in mouth
hematologic effects of sulfonamides
G6PD def for blacks and people of mediterranean orgin. Red cell lysis can produce fever, pallor, jaundice (hemolytic anemia)
can cause agranulocytosis, leukopenia, thrombocytopenia and very rare aplastic anemia
kernicterus
disorder in newborns caused by deposition of bili in the brain. - neurotoxic and can cause severe neurologic deficits and even death.
Sulfonamides should not be given to infants younger than ___and not to pregnant pat after ___ weeks gestation
2 mos
32 weeks gestation
sulfonamides and breastfeeding
no
to minimize the risk for renal damage, adults should maintain a daily urine output of at least ____ mL
1200 (8-10 glasses of water a day)
crystalluria
sulfonamides are contraindicated for pt with creatinine clearance of
severe kidney disease
50% of dose if GFR is 15-30mL/min
Drug interactions and sulfonamides
intensify effects of warfarin, phenytoin and sulfonylurea-type oral hypoglycemics (glipizide, glyburide)
what food can you not take with Sulfadiazine
Vic C or acidifying drinks such as cranberry juice increase risk of crystalluria
which med is for topical derm disorders
Topical Sulfacetamide
sulfonamides and older adults
more likely to experience adverse effects - neutropenia, SJS/ TEN
which is more likely to cause crystalluria
Sulfadiazine
sulfacetamide should not be used by pt with history of severe hypersensitivity to
sulfonamides
sulfonylureas
thiazide or loop diuretics
Trimethoprim inhibits
dihydrofolate reductase
recurrent UTI treated with
Bactrim
Pt ed trimethoprim
early signs of blood dyscrasias -sore throat -fever -pallor report any of these signs
adverse effects trimethoprim
itching rash epigastric distress nausea vomiting glossitis stomatitis hyperkalemia
potential effects of trimethoprim only if preexisting folic acid def
because of the pathway that trimethoprim works on
megaloblastic anemia
thrombocytopenia
neutropenia
what populations would be ad increased risk for folic acid def
excessive alcohol intake
pregnant women
debilitated pt
A pt on trimethoprim has sore throat, fever, pallor
what do you do
CBC
if sig reduction in counts - d/c trimethoprim
administer leucovorin - a reduced form of folic acid
pt pop at high risk due to hyperkalemia while taking trimethoprim
trimethoprim suppresses renal excretion of k and can promote hyper K
Pt at greatest risk are those taking high doses
those with renal impairment
those taking other drugs that can elevate k - ACE, ARB, Potassium sparing diuretics, aldosterone antagonists, potassium supplements
Hyperkalemia typically develops within ___ days of starting Trimethoprim
5
Trimethoprim in pregnancy
no - folate- neural tube defects
Trimethoprim in breastfeeding
no
Bactrim (Trimethoprim/sulfamethoxazole) MOA
SMZ acts to inhibit incorporation of PABA into folate
TMP inhibits dihydrofolate reductase
Bactrim used in
UTIs otitis media bronchitis shigellosis pneumonia from P.jirovecii
CNS effects of Bactrim
headache, depression, hallucinations
drug interactions for bactrim
warfarin
phenytoin
sulfonylurea - type oral hypoglycemics
intensify bone marrow suppression in pt receiving methotrexate
meds that also hyperk
med for bordetella pertussis
erythromycin
which has less microbial resistance
trimethoprim
Sulfonamide
trimethoprim
