Sulfonamides & Trimethoprim Flashcards
Pharmacologic class, MoA, Clinical use, Special considerations, Adverse effects
Folate antagonists
Sulfacetamide Sulfamethoxazole Silver Sulfadiazine Trimethoprim Trimethoprim-sulfamethoxazole
Sulfonamides - MoA
Inhibition of dihydropteroate (PABA + Pteridine) formation (which is usually converted to dihydrofolate by adding glutamate). Preventing DNA synthesis
Trimethoprim - MoA
Inhibition of dihydrofolate reductase (which in a normal process leads to tetrahydrofolate formation).
Sulfacetamide - Clinical use
Blepharitis
Conjunctivitis
Trachoma (Chlamydia trachomatis)
Sulfamethoxazole - Clinical use
UTI’s
Silver sulfadiazine - Clinical use
Burn infections
Superficial skin infections
Nocardia
Trimethoprim - Clinical use
Bacterial prostatitis and vaginitis
Active against many gram-negative bacilli and a few gram-positive organisms.
Trimethoprim-sulfamethoxazole - Clinical use + contra
UTIs, prostatic infections. Serratia, citrobacter, enterobacter
Entereobacteriaceae family (including E. Coli (20% resistant), K. Pneumoniae, Proteus species, and Enterobacter species
Travellers diarrhea
Shigella
Salmonella
Pulmonary infection by Pneumocystis jiroveci(Pneumonia) + Nocardia(Nocardiosis)
Burkholderia cepacia (pneumonia)infections
Staphylococcus aureus both methicillin resistant and susceptible
Some strains of Haemophilus influenzae and Moraxella catarrhalis
Toxoplasmosis
Pregnancy
Sulfonamides - Special considerations
Adequate amounts of water needed to hinder Crystalluria.
Trimethoprim - Special considerations
Ion trapping concentrates the drug in acidic tissues (prostate, vagina), because the drug is a weak base.
Sulfonamides - Adverse effects
Crystalluria
Skin rashes
Hematuria
Obstruction
Stevens-Johnson syndrome (erythema multiforme) (Caused by Mycoplasma pneumoniae & Cytomegalovirus)
GI-reactions Headaches Hepatitis Hematopoietic toxicity Hemolytic anemia (in people with G6PD-deficiency)
Trimethoprim - Adverse effects
Nausea Vomiting Epigastric distress Rashes Hepatitis Thrombocytopenia Leukopenia Other hematologic disorders (including megaloblastic anemia)
Tmx- interaction
Phenytoin, merhotrexate: folate def
Thiazide induced thrombocytopenia
Sulfonylurea: inc hypoglycemic effect
