Bacterial meds

the odd ones

mycoplasma - causes walking pneumonia, doesn’t have traditional cell wall, unaffected by many microbes

Rickettsia - has a rigid cell wall, is vector transmitted

Chlamydiae - has rigid cell wall

treatment for these is different

cultures

specimens should be collected before starting ABX but if they are after, make sure to inform the lab. blood, stool, sputum, wound, throat, urine

culture and sensitivity (C&S)

sensitivity determines what antibiotic the microbe is affected by

Zone of inhibition method

Minimal inhibitory concentration (MIC) method: more common. smaller # = the more sensitive the bacteria is to the agent, takes less of the antibiotic to stop it

bactericidal vs bacteriostatic

bactericidal: kills bacteria vs bacteriostatic: stops the growth of the pathogen - for these treatments pt must have an intact immune system to eliminate the pathogen

selective toxicity

agent selectively kills bacteria by attacking a unique aspect of the bacteria and not human cells = improves therapeutic index

empiric therapy vs focal therapy

empiric therapy is used first - doctor casts a wide net for potential pathogens, uses broad-spectrum ABX, bases on s/sx. focal therapy is for a specific pathogen that has been identified

acquired resistance - ways bacteria defend against ABX

• destroying the ABX using enzymes, ex. penicillinase

• reducing ABX uptake into the bacteria

• altering their structure, making the drug ineffective

super-infections

opportunistic infections that take advantage of altered environment when normal flora are killed by ABX - common side effect of broad spectrum ABX.

sx: diarrhea, suprapubic pain and dysuria, vaginal discharge, oral thrush.

recommend probiotics, cultured yogurt. C. diff - enteric precautions: wash hands with soap, wear gown and gloves, use dedicated equipment

nursing responsibilities for ABX therapy

allergies hx, collect specimens prior to ABX, monitor for allergic reactions, monitor renal function, space ABX doses, monitor for effectiveness of therapy (fever reducing, WBC returning to normal, cough/lung sounds/O2 sats improving, less dysuria/urgency, improving cellulitis)

pt education for ABX therapy

report allergic rxn, wear a medical alert bracelet, compliance is important, interactions are common - pay attention to special labels and instructions

nitrates in urine…

bacteria are in the urine, nitrates are a product of bacterial metabolism

antibiotics

cell wall inhibitors, protein synthesis inhibitors, dna synthesis inhibitors, anti-metabolites

cell wall inhibitors

aka beta lactams

penicillins, cephalosporins, combination agents, carbapenems, vancomycin

penicillins

penicillin, amoxicillin      kill bacteria by disrupting cell wall

most effective against gram positive bacteria like staph and strep - they don’t produce penicillinase

combination agents have PCN + beta lactamase inhibitors

side effects for penicillin

allergy, usually as skin rash/urticaria, may progress to anaphylaxis. if allergic, cephalosporins are also avoided due to possible cross allergy

pt education for penicillin

if given by injection, wait 30 mins, report rash, take PCN on empty stomach, wear medical alert bracelet if allergic

cephalosprorins

look alike sound alike errors are a risk

all begin with cef- or ceph-

use of later generations has replaced earlier ones due to wider range of effectiveness, can enter CSF to treat CNS infections. kill bacteria by disrupting cell wall, beta-lactam ring structure.

used for gram negative bacteria

side effects for cephalosporins

allergic reaction, cross-sensitivity with PCN, pain at IM injection site. for some, avoid alcohol due to disulfiram rxn

vancomycin

has more serious side effects, reserved for serious infections. Has narrow therapeutic margins, requires peak and trough values. is ototoxic and nephrotoxic. Red man syndrome: if infused too rapidly, causes vasodilation and flushing, can look like an allergic rxn, slow down the rate. Side effect: pseudomembranous colitis (C. diff). IV can lead to C. diff, PO treats C. diff.

Protein synthesis inhibitors

ATMs - aminoglycosides, tetracyclines, macrolides interfere with an aspect of bacterial protein synthesis

aminoglycosides

broad spectrum, are IV for serious infections, PO kills bacteria in GI tract before surgery, topical applications like surgical ointment. ototoxic and nephrotoxic

gentamicin, tobramycin, neomycin… -mycin think muscle like protein

tetracyclines

bacteriostatic, treat gram positive and negative, and the odd ones (chlamydia, rickettsiae, mycoplasma)

tetracycline, doxycycline, tigecycline

doxycycline is used prophylactically for malaria

considerations for tetracyclines

side effects: teeth discoloration, contraindicated in pregnancy, lactation, children (binds to calcium on teeth), photosensitivity

nursing: do not give with milk products, separate from supplements or antacids, take on empty stomach (binds to calcium = reduce efficacy)

pt: take away from other meds and food, avoid sun

macrolides

advantage is once/twice a day dosing. “z-pack”

erythromycin, azithromycin, clarithromycin throw microbes out of here

broad spectrum, treats gram - and +, alternative to PCN

macrolides special considerations

monitor for jaundice, elevated liver enzymes = side effect: hepatotoxicity. take on empty stomach away from minerals like calcium and iron (decrease efficacy).

DNA synthesis inhibitors

fluoroquinolones/quinolones

ciprofloxacin, levofloxacin    -floxacin, they f up the DNA

special considerations for quinolones

side effects: tendonitis and rupture, risk populations: children, teens, elderly. particularly the Achilles tendon

nurses: monitor for heel and ankle pain, administer away from meals or supplements

pt: report heel/ankle pain, take med on empty stomach

if pregnant…

don’t take quinolones or tetracyclines

anti-metabolites

sulfonamides: trimethoprim-sulfamethoxazole (TMP-SMX)

inhibits bacterial synthesis of folic acid. TMP-SMX inhibits folic acid synthesis at different sites so they are more effective together.

special considerations for anti-metabolites

used for UTIs, PJP - Pneumocystis pneumonia fungi in AIDS pts prophylactically and treatment.

side effects: bone marrow depression w/ long term use = anemia, low WBC, thrombocytopenia, photosensitivity, crystals in urine = nephrotoxic.

nurses: assess for sulfa allergy, monitor for hypersensitivity & SJS, monitor CBC, assess renal function and crystalluria, make sure they hydrate, double check singe or double-strength

pt ed: drink lots of water or cranberry juice, call if develop a rash, OK to take with dairy products, avoid sun

TB drugs

PRIEST

Pyrazinamide: interferes with bacterial metabolism

Rifampin: prevents protein synthesis in cell wall

Isoniazid (INH): monotherapy for latent TB, also used in combination

Ethambutol: interferes with bacterial metabolism

STreptomycin

TB treatment

complex, long term, minimum 6 months, changing combination of drugs

side effects for TB treatment

Pyrazinamide: hepatotoxicity

Rifampin: Reddish-orange ALL body fluids, hepatotoxicity

INH: peripheral neuropathy (taking B6/pyridoxine helps prevent this), hepatotoxicity

Ethambutol: Eye pain, visual disturbances, can lead to blindness

Streptomycin: nephrotoxic, ototoxic

nursing implications for TB

airborne precautions: negative pressure room, keep door closed, wear fit-tested respirator. monitor labs: CBC, LFT, AFB sputum test. Assess for side effects of drugs

Pt teaching for TB treatment

report side effects promptly, long-term therapy, no alcohol - risks for liver injury, never stop taking meds until 2 sputum cultures are negative for AFB, cover mouth when coughing/sneezing, wear a mask in public.

INH: avoid tyramine (aged cheese, smoked fish, beer, wine, chocolate) = can cause an unpleasant rxn - red, itchy skin, chills, sweating