Drugs Flashcards
Strategies toward development of new antibiotics
- Combat bacterial resistance mechanisms: develop inhibitors of drug inactivating proteins and efflux transporters, develop drug analogs that are resistant to drug-inactivating proteins
- ID new targets for chemotherapy for chemotherapy
Aminoglycosides
Antibiotics that inhibit protein synthesis
Includes streptomycin, tobramycin, gentamicin, amikacin, neomycin, kanamycin
Targets 30S ribosomal subunit to irreversibly interfere with protein synthesis by either blocking initiation, blocking ribosomal translocation, or causing mistranslation
Post-antibiotic effect
Bactericidal against many aerobic gram negative bacteria
Streptomycin
Aminoglycoside
Used as second-line treatment for TB (in combo with other agents to inhibit resistance)
Tobramycin
Most clinically used aminoglycoside
Used for severe infections caused by aerobic Gram- bacteria that are resistant to other drugs
Often used in combo with beta-lactam antibiotics because synergystic
More expensive than gentamycin
Gentamicin
Most clinically used aminoglycoside
Used for severe infections caused by aerobic Gram- bacteria that are resistant to other drugs
Often used in combo with beta-lactam antibiotics because synergystic
More cheaper than tobramycin
Amikacin
Aminoglycosides
Only really used in cases of resistance to tobramycin and gentamicin (there are many bacterially-produced enzymes that cause inactivate tobramycin and genamicin)
Neomycin
Aminoglycoside
Restricted to topical use only because very toxic (neosporin)
Kanamycin
Aminoglycoside
Restricted to topical use only because very toxic
Adverse Effects from Aminoglycosides
Reversible nephrotoxicity
Irreversible ototoxicity (auditory damage and/or vestibular damage)
Auditory damage include tinnitus, high frequency hearing loss
Vestibular damage includes vertigo and ataxia
More likely to occur with use of aminoglycosides longer than 5 days
Tetracyclines
Inhibit protein synthesis
By blocking 30s ribosomal subunit, inhibit peptide elongation
Bacteriostatic for many aerobic Gram+ and -, including rickettsiae, chlamydiae, and mycoplasmas
Used for rickettsial infections (RMSF, typhus, and Q fever), STIs (chlamydia, urethritis, cervicitis, and epididymititis), respiratory tract infections (pneumonia), Lyme’, anthrax, malaria, and skin/soft tissue infections
Absorption is impaired by food and multivalent cations (Ca2+, Mg2+, Fe2+, and Al3+) cause chelation
Includes tetracycline, oxytetracycline, demeclocycline, minocycline, doxycycline, and tigecycline (first two have VERY short half life)
Adverse Effects from Tetracyclines
GI problems (nausea, vommitting, diarrhea)
Tooth discoloration and deformity, especially in children
Photosensitization (easily sunburn)
Hepatoxicity during pregnancy
Doxycycline
Tetracycline used for treatment and prevention of malaria, anthrax, and treatment of Lyme
Tigercycline
An IV tetracycline with a long half life used for treatment of community acquired pneumonia, intra-abdominal, skin and soft tissue infections cause by MDR bacteria (MRSA, VRE, etc)
Macrolides
Inhibit protein synthesis
Bind to the 50S subunit to inhibit ribosomal translocation
Bacteriostatic against aerobic Gram+ and some Gram- bacteria
Used for community acquired pneumonia, bronchitis, otitis media, strep throat, chlamydia, diptheria, pertussiss
Erythromycin, carithromycin, azithromycin, and telithromycin
Can cause GI problems and hepatotoxicity
Azithromycin
Macrolide with long half life
Aka Z-Pak
Lincosamide
Inhibits protein synthesis
Binds to 50S subunit and interferes with protein synthesis by blocking ribosomal translocation
Bacteriostatic ONLY against aerobic and anaerobic Gram+ bacteria
Used for soft tissue and skin infections
Can cause diarrhea, pseudomembranous colitis caused by C. dif, and skin rash
Adverse effects from macrolides
Hepatotoxicity-through hypersensitivity reaction
GI Effects-stimulate gut motility-anorexia, nausea, vomiting, and diarrhea accompanying oral administration
Strepogramins
Protein synthesis inhibitors
Bind to 50S ribosomal subunit to inhibit ribosomal translocation
For VRE and MSSA (not MRSA)
Used against Gram+ bacteria
Quinupristin and dalfopristin
Oxazolidinone
Protein synthesis inhibitors
Bind to 50S to inhibit initiation step of protein synthesis
Used against aerobic and anaerobic Gram+
Used for treatment of infections caused by MDR gram+ bacteria (MRSA, VRE, and penicillin resistant streptococci)
Sulfonamides
Inhibit DNA synthesis (anti-folate)
Competitive antagonist of dihydropteroate synthase needed for purine synthesis; act as PABA analogs
Bacteriostatic when used as single agent; bactericidal when used with tripmethoprim (which inhibits DNA synthesis further downstream)
Sulfisoxazole, sulfamethoxazole, and sulfasalazine
Sulfisoxazole
Sulfonimide (antifolate DNA synthesis inhibitor)
Used for UTIs
Sulfamethoxazole
Sulfonimide (antifolate DNA synthesis inhibitor)
Used for UTIs
Sulfasalazine
Sulfonamide (anti-folate DNA synthesis inhibitor)
Used for ulcerative colitis, enteritis, and other IBD
Has anti-inflammatory properties