Week 8, 9, 10 Pharmacy Notes PDF

11/19 WEEK 8 – Chemotherapy for infectious diseases 1. Basic Principles of Antimicrobial Therapy – final is Tuesday December 10 th at 8:30 am 50 questions Selective Toxicity:  Selective toxicity allows antimicrobial  Mechanisms include disruptin...

11/19 WEEK 8 – Chemotherapy for infectious diseases 1. Basic Principles of Antimicrobial Therapy – final is Tuesday December 10 th at 8:30 am 50 questions Selective Toxicity:  Selective toxicity allows antimicrobial  Mechanisms include disrupting the bacterial agents to harm the microbe without harming cell wall, inhibiting enzymes unique to the host by targeting structures or processes bacteria, or disrupting bacterial protein unique to microbes. synthesis. Classification of Antimicrobial Drugs: used to treat infectious diseases  Susceptible organisms: - Antibacterial (narrow and broad-spectrum), - Constantly evolving microbial resistance antiviral (e.g., HIV, influenza), antifungal. - Currently effective antibiotics will be - There are organisms that respond poorly to rendered useless available drugs Mechanisms of action: o Inhibition of cell wall synthesis, disruption of cell membrane permeability, inhibition of protein synthesis, synthesis of nucleic acids, antimetabolites, and viral enzyme inhibitors. Bactericidal – directly lethal to bacteria at clinically achievable concentrations GOOD CHOICE FOR COMPLLICATED OR SEVERE INFECTIONS OR THOSE WITH WEAK IMMUNE SYSTEM Bacteriostatic – slow bacterial growth but are not directly lethal DOES NOT KIILL, HOST IMMUNE SYSTEM MUST KILL THE BACTERIA Acquired Resistance:  Resistance develops over time and reduces drug efficacy. Causes include: - Reduced drug uptake. - Drug inactivation by microbial - Alteration of drug targets. enzymes.  Examples include MRSA and drug-resistant TB.  Superinfection: a new infection that appears during treatment for a primary infection o Kills the normal flora letting second infection flourish o Ex. Candida in females Selection of Antibiotics:  Perform cultures before initiating therapy.  Use broad-spectrum antibiotics initially; shift to narrow spectrum once culture and sensitivity results are available.  Consider host factors: site of infection, allergies, and immune status. Host Factors:  Conditions like renal or hepatic impairment, genetic factors, and previous allergic reactions can affect drug choice and dosage. Dosage Size and Duration: - Ensure sufficient drug levels at the site of - Educate patients to complete their antibiotic infection for an adequate time. regimen to prevent resistance Therapy with Antibiotic Combinations:  11/19 - Reduces the risk of resistance but may - Used to treat mixed infections or enhance increase the risk of adverse effects. efficacy (synergy). Prophylactic Use:  Preventative use for surgeries, bacterial endocarditis, or neutropenia. Misuse of Antimicrobials:  Avoid unnecessary use (e.g., treating viral infections with antibiotics).  Use appropriate drug, dose, and duration. Monitoring Therapy:  Regularly assess clinical and lab indicators like resolution of signs and symptoms r/t affected organ and drug toxicity (e.g., serum levels).  Frequency of monitoring should increase with severity of infection 2. Therapeutic Goals, Routes of Administration, and Minimizing Adverse Effects for Drugs Weakening Bacterial Cell Walls Penicillin’s: active against a variety of bacteria  Beta-lactam ring in their structure  Beta-lactam family – also includes cephalosporins, carbapenems, and aztreonam  Beta-Lactamase Inhibitors: extends antimicrobial spectrum when combined with penicillinase- sensitive antibiotics Therapeutic Goals:  Achieve bacterial eradication by disrupting the bacterial cell wall, causing cell lysis. Active only against bacteria that are undergoing growth and division  Bactericidal Routes of Administration: Penicillin: IV, IM, or PO (Penicillin V). most common cause of drug allergies Vancomycin: IV for systemic infections, PO for C. diff. if metronidazole is found ineffective - Inhibits cell wall synthesis - Methicillin-resistant Staphylococcus aureus - Severe infections only or Staphylococcus epidermidis Adverse effects: - renal failure/nephrotoxicity - phlebitis at site of IV - ototoxicity (reversible or permanent) - anaphylaxis - rapid infusion can cause flushing, rash, pruritus’, - thrombophlebitis (common) urticaria, tachycardia and hypotension Factors of bacterial resistance with PCN’s  Inability of penicillins to reach targets  Inactivation of penicillins by bacterial enzymes  Production of penicillin-being proteins that have low affinity for penicillin’s Classification of penicillin Narrow-spectrum penicillin’s: nafcillin, oxacillin, Broad-spectrum penicillins: ampicillin and and dicloxacillin amoxicillin. Rash, diarrhea (AR) kills gram negative bacilli  11/19 Extended-spectrum penicillin’s: Piperacillin infections that often occur in immunocompromised host and are difficult to eradicate P. aeruginosa Penicillin G benzylpenicillin Class – narrow spectrum penicillin’s: Penicillinase Uses – infections caused by Neisseria meningitidis, sensitive Neisseria gonorrhoeae, treponema pallidum Action – bactericidal to a number of gram+ and some gram – organisms Routes: IV, IM (NEVER PO) PNC V and VK is PO Adverse effects o Least toxic of all antibiotics o Penicillin is the most common cause of drug allergy Minimizing Adverse Effects: Monitor for penicillin allergy, Administer vancomycin slowly to Regularly check renal function and skin tests prevent "red-man syndrome." trough levels to avoid nephrotoxicity and ototoxicity.  If Hx of mild reaction, consider cephalosporin  If Hx of anaphylaxis – avoid administration of penicillin or cephalosporin  Types: o Immediate (reaction in 2 to 30 min) o accelerated (reaction takes days or weeks to develop) o Late (reaction takes days or weeks to develop)  Anaphylaxis o Laryngeal edema o Bronchoconstriction o Severe hypotension Ongoing Evaluation:  Monitor for resolution of infection symptoms, renal function (BUN, creatinine), and IV site integrity. Cephalosporins: Most widely used group of antibiotics - beta-lactam antibiotics - usually given parenterally - like penicillin structure - bactericidal - Toxicity is low Mechanism of action: Binds to penicillin-binding proteins (PBPs), disrupt cell wall synthesis, and cause cell lysis Resistance: Beta-lactamases (cephalosporinases). 3rd and 4th generation agents more resistant than 1st and 2nd Pharmacokinetics: - Poorly absorbed from GI given IV and IM - Distributes well to most of the body fluids and tissues. 3 rd – 5th generations distribute better in CSF - Kidneys eliminate so you must watch kidney function Drug interactions: Probenecid, alcohol, drug that promote bleeding, calcium and ceftriaxone  11/19 Adverse effects: Allergy, bleeding, thrombophlebitis USES: broad spectrum, bactericidal drug with high therapeutic index, employed widely and successfully with many infections, and can be used as an alternative for pts. with MILD PCN allergies Carbapenem: Beta-lactam antibiotics have an extremely broad antimicrobial spectrum with low toxicity, caused bacterial cell wall weakening, lysis, and death. NOT active against MRSA Route: parental Hypersensitive reactions: rash 3. Nurses' Roles and Responsibilities in Preventing and Treating Resistant Infections (e.g., MRSA, C. diff) MRSA (Methicillin-Resistant Staphylococcus aureus): MRSA  Colonizes skin and nostrils; transmitted via contact.  Prevention: o Hand hygiene with soap and water. o Keep infected sites covered o Proper wound care and cleaning of o Showering after contact sports frequently touched surfaces C. diff (Clostridium difficile): generally referred to as superinfection  Often arises after broad-spectrum antibiotic use.  Transmitted via spores, commonly by healthcare workers.  Prevention: Wash hands with soap and water (alcohol- Use dedicated equipment for infected based sanitizers are ineffective). patients. Treatment for both: o Administration: Follow prescribed protocols for vancomycin (for MRSA) or metronidazole/fidaxomicin (for C. diff). o Monitoring: Regularly assess drug efficacy and adverse effects. o Isolation: Manage patient placement in isolation to prevent hospital outbreaks. o Education: Inform patients about completing antibiotic courses and potential side effects.  11/19 WEEK 9 - Chemotherapy for infectious diseases II 1. Identify and describe the nurses’ roles and responsibilities in prevention and treatment of infectious agents that are resistant to antimicrobial therapy including MRSA and C. diff. In objectives above  Prevention: o Hand hygiene: Frequent, proper handwashing to prevent transmission. o Contact precautions: Use gloves, gowns, and possibly masks for patients with resistant infections. o Environmental cleaning: Ensure frequent and thorough cleaning of surfaces and equipment. o Antibiotic stewardship: Advocate for proper antibiotic use to minimize resistance. o Education: Teach patients and families about hygiene and infection prevention.  Treatment: o Administration: Follow prescribed protocols for vancomycin (for MRSA) or metronidazole/fidaxomicin (for C. diff). o Monitoring: Regularly assess drug efficacy and adverse effects. o Isolation: Manage patient placement in isolation to prevent hospital outbreaks. o Education: Inform patients about completing antibiotic courses and potential side effects. 2. Identify and describe the mechanism of action, therapeutic uses, nursing administration responsibilities and ongoing evaluation and interventions for minimizing adverse effects when giving drugs that inhibit or disrupt bacterial protein synthesis or drugs which disrupt the synthesis of tetrahydrofolic acid. Drugs Inhibiting Protein Synthesis: Tetracyclines: doxycycline, minocycline, and demeclocycline are all Bacteriostatic  Most given by PO Uses: - severe acne - anthrax - H. Pylori ulcers - peptic ulcer disease - rocky mt. spotted fever - dental disease Pharmacokinetics: distributes widely to most tissues and body fluids Elimination is mainly kidneys as well as liver Absorption of tetracyclines decrease if given with calcium and magnesium - Milk products - Magnesium-containing laxatives - Calcium and iron supplements - Most antiacids Precautions: - No pregnant women; causes discoloration of baby - High dose IV has been associated with severe liver teeth. No one under age 8! damage - Photosensitivity, use sunscreen! - C.diff (life threatening form) report diarrhea, and - Decreases efficacy of oral birth control, use yeast infections backup form Administration Responsibilities: - Collect cultures before - Watch WBCs - Monitor renal and liver initiating therapy. function tests  11/19 Macrolides: Azithromycin and clarithromycin usually bacteriostatic but can be bactericidal - active against most gram + and some Gram – - Erythromycin is prototype of drug, take as prescribed with empty stomach Vs. With food (depending on med) Uses: - if patient is allergic to - whooping cough - M. pneumoniae penicillin - acute diphtheria - upper and lower resp. tract - strep throat - corynebacterium diphtheriae infections - before cultures come back - chlamydial infections - acute otitis media (broad spectrum) - Drug interactions: inhibits hepatic metabolism of other drugs and elevate their levels particularly Warfarin, carbamazepine, and theophylline (those drugs dosages may need to be reduced) Adverse effects: - gastrointestinal – pseudomembranous colitis, - Superinfection diarrhea and C.diff - Ototoxicity - QT prolongation and sudden cardiac death - photosensitivity (unlikely) Nursing responsibilities: - C & S before starting therapy - Assess for GI or Abd. pain, diarrhea, bloody stools - monitor CBC with differential and renal and liver - check for ototoxicity enzymes - observe for S&S of anaphylaxis - tell pt. to report any blood stools or diarrhea Clindamycin/Cleocin: can be bacteriostatic or bactericidal - active against most anaerobic bacteria (gram + and Gram - ) Routes: PO, IM, IV Uses: only certain anaerobic infections located OUTSIDE the CNS. Not for meningitis etc. Adverse Effects: CPAD aka AAPMC, Can induce Severe C.Diff Nursing responsibilities: - check C & S before treatment - monitor renal and liver - monitor GI status, pains, and stools functions before therapy – notify dr. immediately if any occur Aminoglycosides: Gentamicin (most common), tobramycin, amikacin (bactericidal) - narrow spectrum antibiotics - some microbial resistance - not absorbed through the GI tract - Use cautiously in pts. with myasthenia gravis???? Routes: eye drops or systemically IV Use: Aerobic Gram– bacilli Adverse effects: - ototoxicity/tinnitus - nephrotoxicity - hypersensitivity Beneficial Drug interactions: Adverse drug interactions: - used in combination with other Abx. (penicillin’s, - given with other ototoxic or nephrotoxic drugs can cephalosporins and vancomycin) but must be intensify neuromuscular blockade induce by careful with kidneys pancuronium and other skeletal muscle relaxants  11/19 Dosing: Single large dose each day or 2-3 smaller dose - Monitoring for serum levels is very common as the same dose in two people can lead to different serum level - peak serum levels must be high enough to kill bacteria; trough levels must be low enough to minimize toxicity Peak and trough must be timed very specific ( not even 10min to spare) Nitrofurantoin: Broad spectrum Bacteriostatic at low concentrations and Bactericidal at high concentrations Uses: Acute infections of lower urinary tract (urethra and bladder) - Not recommended for upper tract UTIs (pyelonephritis) or complicated infections Adverse Effects: - GI upset - Neuro: damage to sensory and motor nerves - Resp. dyspnea, angina, chills fever, cough (muscle weakness, tingling sensations and - Hemo: agranulocytosis, leukopenia, numbness, report and DC) thrombocytopenia - hepatotoxic - birth defects: use alternative antibiotics Drugs Inhibiting Tetrahydro- Folic Acid Synthesis: Sulfonamides and trimethoprim - broad spectrum - 1st drugs available for systemic treatment of bacterial infection (more effective and less toxic drugs now available - Uses: urinary tract infection (primary), Otitis media, ulcerative colitis etc. TMP/SMZ: trimethoprim and sulfamethoxazole together in a fixed-dose combination production it is a powerful antimicrobial - Two strengths (double and regular) - PO sometimes IV Uses: Otitis media, bronchitis, shigellosis, and pneumonia caused by P. Jiroveci Adverse effects: - renal damage from crystalluria - steven Johnson syndrome - hyperkalemia (flush with water) - fever/malaise - hematologic effects - megaloblastic anemia (if folate - kernicterus: bilirubin in brain - birth defects deficiency is present) of newborns (permanent) Drug interactions: - intensify the effects of warfarin phenytoin and sulfonylurea-type oral hypoglycemics (reduce those drug dosages) Nursing responsibilities: - C&S prior to therapy - Monitor CBC with differential - do not give in 1st trimester and liver/renal labs - assess for allergies to sulfonamides - inspect IV site phlebitis is - Do not give to women near common term, nursing moms, and infants - monitor I&Os, and promote under the age of 2 fluid intake - discontinue with first sign of rash (kernicterus) Teaching:  11/19 - take as directed - notify HCP if skin rash, sore throat, fever, mouth - use sunscreen/protective clothing sores, or unusual bleeding/bruising occurs - increase fluid intake 3. Identify and describe the common medications used for UTIs, nursing administration responsibilities and ongoing evaluation, interventions for minimizing adverse effects and education needed for patients taking these medications throughout objectives above ^^^^  Common Medications: o Sulfonamides, trimethoprim (or TMP-SMZ) o PCNs (sometimes) o Aminoglycosides o Cephalosporins o Fluoroquinolones o Cephalosporins o urinary tract antiseptics (nitrofurantoin and Methenamine)  Administration Responsibilities: throughout objective 2 o Perform C&S tests before starting antibiotics. o Encourage increased fluid intake to flush the urinary tract and reduce crystalluria risks. o Monitor renal and hepatic function (especially with nitrofurantoin).  Patient Education: throughout objective 2 o Maintain hydration (6–8 glasses/day). o Take the full course of antibiotics as prescribed. o Report symptoms of allergic reactions or side effects like numbness (nitrofurantoin neurotoxicity). o Practice hygiene measures like wiping front to back and urinating after intercourse. 4. Discuss serum drug level monitoring to minimize ototoxicity and nephrotoxicity.  Aminoglycosides (gentamicin): o Monitor peak levels to ensure sufficient bactericidal activity. o Monitor trough levels to avoid toxicity. o Regularly assess renal function (BUN, creatinine) and auditory changes (hearing loss, tinnitus).  Nursing Actions: o Adjust dosage based on serum levels. o Avoid concurrent nephrotoxic or ototoxic drugs when possible. o Educate patients about symptoms of toxicity. 5. Identify populations that should not be administered sulfonamides  Contraindications: o Pregnant women near term and nursing mothers (risk of kernicterus in newborns). o Infants under two years old. o Patients with a sulfonamide allergy. o Patients with folate deficiency (risk of megaloblastic anemia).  11/19 6. Discuss the prevalence of UTIs and prevention measures to reduce the risk of these infections. Prevalence: - Second most common infection, affecting mainly women due to shorter urethra and proximity to the anus. - E. coli is the most common causative agent. Prevention Measures: - Incorporate probiotics and reduce caffeine and - Stay hydrated and urinate frequently. alcohol. - Urinate before and after intercourse to flush - Practice proper hygiene (wiping front to back). bacteria. - Avoid irritants like scented feminine products. - Limit alcohol and caffeinated drinks WEEK 10 – Fluids and electrolytes 1. Identify and describe factors that should be considered when selecting a diuretic, when to use various agents, and the potential for adverse effects in patients with other disorders. Also discuss for which pathologies the various diuretics are suitable. Most diuretics cause the blockade of Na+ and Chloride absorption Impact on ECF: may cause hypovolemia, acid base imbalance, and electrolyte imbalances 1. Therapeutic Goal: o Loop diuretics (Furosemide): Used for acute pulmonary edema (most common), severe hypertension, and renal failure. loop of Henle o Thiazides (Hydrochlorothiazide): Effective for essential hypertension, diabetes insipidus (1) and mild edema. Early segment distal convoluted tubule o Potassium-sparing diuretics (Spironolactone): Suitable for conditions requiring potassium conservation. Distal convoluted tubule o Osmotic diuretics (e.g., Mannitol): Used in intracranial or intraocular pressure reduction. Proximal convoluted tubule 2. Patient Comorbidities: o Patients with diabetes: Risk of hyperglycemia with thiazides and loop diuretics. o Gout: Risk of hyperuricemia with thiazides and loop diuretics. o Heart failure: Spironolactone improves survival in severe cases. 3. Electrolyte Concerns: o Risk of hypokalemia with thiazides and loop diuretics. o Risk of hyperkalemia with potassium-sparing diuretics. Pathologies and Suitable Diuretics  Hypertension: Thiazides are first-line; potassium-sparing diuretics, Loop diuretics (in crisis)  Edema (heart failure, cirrhosis): Loop diuretics for rapid fluid removal, potassium sparing for Heart failure  Edematous states (third spacing, etc.): Loop diuretics, potassium sparing,  Renal Failure: Loop diuretics maintain urine output.  Intracranial Pressure: Osmotic diuretics like Mannitol.  Acne or Hormonal Imbalances: Spironolactone due to anti-androgen effects.  11/19 2. Describe the adverse effects, contraindications, or precautions for the various diuretics. Loop Diuretics (Furosemide): PO and IV (rapid onset of 5 min) Pt. must be able to pee. WATCH K+ CLOSELY o Action: o Adverse Effects: Hypokalemia, hyponatremia, hypotension, ototoxicity (IV), dehydration, hyperuricemia, lipids, Ca, Mg, a lot of diuresis o Contraindications: Severe electrolyte depletion, pregnancy, hypokalemia (call provider) o Drug interactions: Digoxin, antihypertensive agents, ototoxic drugs, K+ sparing diuretics, NSAIDS Thiazides (Hydrochlorothiazide): max diuresis is lower than loop diuretics. NOT effective if urine flow is scant. Peaks in 4-6 hours o Action: increase renal excretion of sodium, o Contraindications: Anuria, hypersensitivity, chloride, potassium and water pregnancy, hyperglycemia in diabetes, gout, lipids and magnesium o Adverse Effects: Hypokalemia, hyperglycemia, o Drug interactions: Digoxin, augments of hyperlipidemia, hypertensive medications, NSAIDS, can mix with ototoxic drugs Potassium-Sparing Diuretics (Spironolactone): least amount of diuresis o Action: blocks aldosterone in distal nephron, o Contraindications: Hyperkalemia, severe renal retains K+, increases excretion of Na+ impairment. o Adverse Effects: HYPERkalemia, endocrine o Drug interactions: ACE inhibitors, thiazide and effects TONS! Electrolyte imbalances, benign and loop diuretics malignant tumors, post-menopausal bleeding, kidney impairment Osmotic Diuretics (Mannitol): very powerful, used very sparingly, given by IV o Adverse Effects: Edema, o Contraindications: Anuria, o Action: preserve urine flow CHF, fluid/electrolyte intracranial bleeding and prevent kidney failure imbalances, headache, N/V (uncontrolled). 3. Identify and describe the common etiologies and treatments for respiratory and metabolic acidosis and respiratory and metabolic alkalosis. Respiratory Acidosis  Etiologies: Hypoventilation, COPD, respiratory depression.  Treatment: Improve ventilation (e.g., CPAP, intubation), treat underlying cause. Respiratory Alkalosis  Etiology: Hyperventilation (anxiety, fever, sepsis).  Treatment: Rebreathing CO₂ (paper bag), sedatives for anxiety. Metabolic Acidosis  Etiologies: Renal failure, ketoacidosis, lactic acidosis.  Treatment: Correct underlying cause, sodium bicarbonate if severe. Metabolic Alkalosis  Etiologies: Vomiting, diuretic use, hypokalemia.  Treatment: Address cause, replace potassium, administer acidifying agents if needed.  11/19 4. Identify treatments and prevention of potassium and magnesium imbalances. Potassium: most abundant in ICF, maintains electrical excitability of muscle, regulating acid/base balance, cardiac contractions o Regulation: primarily by the kidneys, renal excretion increased by aldosterone and most diuretics (NOT K+ sparing ones) influenced by extracellular pH (Alk = k+ uptake enhanced, Acid = K+ exits cells) insulin also effects on k+ level Hypokalemia: less than 3.5mEq/L o Causes: Diuretics (loop, thiazides), diarrhea, vomiting. o Treatment: Oral or IV potassium supplements. NEVER PUSH K+, diluted down very well, given slowly o Prevention: Use potassium-sparing diuretics or supplements. Not for patients with renal failure, or high K+ Hyperkalemia: o Causes: Potassium-sparing diuretics, renal failure, severe tissue trauma, od of IV K+, addisons disease o Treatment: Calcium gluconate, insulin with glucose, dialysis. o Prevention: Monitor potassium levels, avoid high-potassium diets with risks. Magnesium Imbalance 1. Hypomagnesemia: o Causes: Alcoholism, diuretics, malabsorption. o Treatment: Oral or IV magnesium sulfate. o Prevention: Magnesium-rich foods (nuts, green vegetables), supplements. 2. Hypermagnesemia: o Causes: Renal failure, excessive magnesium intake. o Treatment: IV calcium gluconate, diuretics, dialysis. o Prevention: Avoid excessive magnesium in at-risk patients.