Pharmacology Exam 3

• Antihistamines

  MOA: Block action of histamine at H1 receptor sites, compete with histamine for binding at unoccupied receptors but cannot push it off if already bound. 

  Two types of antihistamines:

  • Traditional: Centrally/peripherally acting or first generation
  • Nonsedating: Peripherally acting, second generation. 
• Diphenhydramine (Benadryl) - first generation H1 receptor antagonist → works peripherally and centrally, prototype drug

  • MOA:  blocks effects of histamine by competing and occupying H1 receptor sites 
  • Indications: often combined with analgesic, decongestant, or expectorant in OTC cold and flu products. 

  Topically to treat rashes, minor allergies.

  PO IM and IV for severe allergic reactions

  Can be used for PD 

  Motion sickness, n/v
• Diphenhydramine (Benadryl) - first generation H1 receptor antagonist → works peripherally and centrally, prototype drug

  • AE: Drowsiness, paradoxical CNS stimulation and excitability can be observed rather than drowsiness. Dry mouth, tachycardia, and mild hypotension. 
• Diphenhydramine (Benadryl) - first generation H1 receptor antagonist → works peripherally and centrally, prototype drug

  • Contraindications: BPH, narrow angle glaucoma, and GI obstruction. Use with caution in asthma or hyperthyroidism.
  • Interactions: CNS depressants, alcohol, opioids → cause increased sedation. 
  • OTC cold preparations may increase anticholinergic side effects. 
  • MAOIs may cause hypertensive crisis
• Fexofenadine (Allegra) - second generation drug, only works peripherally

  • MOA: Histamine 1 blocker, second generation. Works peripherally thus fewer CNS AE’s. Longer duration of action → increases compliance. 

  Indications: Seasonal allergies, allergic rhinitis.
• Oxymetazoline (Afrin)

  • MOA: Alpha 1 agonist → causes vasoconstriction in nasal mucosa thus drying the mucous membranes and reduces swelling. 
  • Rebound after 3 days!
  • Indication: Nasal congestion, epistaxis 
  • AE’s: Rebound congestion (3-5 days), nasal stinging and dryness, hypertension
  • Contraindications: Careful use in thyroid disorders, hypertension, diabetes, heart disease. Avoid with St. John’s wort (plant).
• Fluticasone (Flonase)

  • MOA: topical (inhaled steroid). Potent anti-inflammatory effect by decreasing immune system cells involved in the inflammatory response → decreases local inflammation in the nasal passages = reduces nasal stuffiness.
  • Indication: nasal congestion due to seasonal allergies, allergic rhinitis 
  • Adverse effects: Nasal irritation, epistaxis, headache, nasopharyngitis
  • Contraindications: Known bacterial, fungal, or parasitic infections (especially in resp tract), narrow angle glaucoma.
• Nasal Decongestants: Nursing Implications

  Report a fever, cough, or other symptoms lasting longer than 3 weeks. Patients taking inhaled steroids should be monitored for localized infection.
• Intranasal steroids for allergies-indications

  Nasal congestion due to Seasonal allergies, allergic rhinitis
• Acetylcysteine (Mucomyst) 

  • Indications: break down thick mucous secretions in COPD, pulmonary fibrosis. Also used as antidote for acetaminophen overdose.
  • Education: Not used in asthma because of risk of bronchospasms (inhaled from) and not for patients with inability to cough. → pulmonary hygiene education.
• Antitussives ONLY FOR NON-PRODUCTIVE COUGH
• Cough evaluation

  Respiratory secretions and foreign objects are naturally removed by the: cough reflex

  • Cough reflex induces coughing and expectoration. It is initiated by irritation of sensory receptors in the respiratory tract. 

  Productive cough: due to congested, removes excessive secretions

  Nonproductive cough: dry cough
• Asthma steps

  Step 1 - SABA PRN

  Step 2 - Low dose inhaled corticosteroids (ICS) daily

  Step 3 - Low dose ICS + LABA (long acting beta agonists) or medium dose ICS 

  • Most important step because that is the midpoint. 

  Step 4 - Medium dose ICS + LABA

  Step 5 - High dose ICS + LABA, + long acting muscarinic antagonist (LAMA), consider biologics

  Step 6 - High dose ICS + LABA, oral CS, consider biologics
• Medications for acute asthma attacks

  Rescue medications (PRN or quick relief)

  • SABA - albuterol - treatment for acute exacerbations
  • LABA + inhaled steroid (Symbicort)

  
  

  Disease modifying (Maintenance given daily aka long-term controllers)

  • Inhaled steroids like Budenoside (Pulmicort) or Fluticasone (Flovent)
• COPD medications: indications

  Rescue medications (PRN)

  • SABA - albuterol - first line treatment for acute exacerbations
  • Nebulized anticholinergics - LAMAs such as ipratropium bromide (Atrovent) 
  • *Rescue when combined with albuterol- DuoNeb*
  • Systemic steroids - ER/Severe exacerbations - methylprednisolone (SoluMedrol) IV, Prednisone PO. 
• COPD medications: indications

  Disease modifying

  • Inhaled anticholinergics - LAMAs such as tiotropium bromide (Spiriva) - LABAs like Salmeterol 
  • Oxygen - only medication that decreases mortality in COPD but only if needed 
  • Inhaled steroids - budesonide (Pulmicort), Fluticasone (Flovent) (with > eosinophils)
• LABAs (long acting beta agonists)

  • Arformoterol (Brovana) 
  • Formoterol (Foradil, Perfoomist)
  • Salmeterol (Serecent), if combined with corticosteroid fluticasone
• Albuterol (Ventolin)

  Rescue drug that quickly reduce airway constriction and restore normal airflow. Not recommended for asthma prophy. Inhaled 15-30 minutes prior to physical activity, it can prevent exercise-induced bronchospasm. 
• Albuterol (Ventolin)

  • MOA: Moderately selective beta 2 receptor agonist → Bronchodilator (relax bronchial smooth muscle and cause dilation of the bronchi and bronchioles) 
  • High doses can still cause some beta 1 response (nervousness, tremor, increased pulse) 

  Indications: SABAs - ONLY during acute asthma/COPD exacerbations.
• Albuterol (Ventolin)

  • AE’s: Palpitations, headaches, throat irritation, tremor, nervousness, restlessness, tachycardia. Insomnia and dry mouth less common. Hyperglycemia, hypokalemia. 
  • Contraindications: Caution in cardiac disease or HTN
  • Avoid caffeine or other stimulants.

  Interactions: Beta blockers (antagonist effects), MAOIs within 14 days.
• SABA

  • Used for quick relief of sudden asthma symptoms like wheezing or shortness of breath. Not for daily maintenance.

  Follow these steps:

  Shake well: Give the inhaler a good shake before each use.

  Breathe out: Blow out all the air from your lungs.

  Position and puff: Place the mouthpiece in your mouth with a good seal and press down on the inhaler as you start to breathe in slowly and deeply.

  Hold and exhale: Hold your breath for 10 seconds (if you can) and then breathe out slowly.

  Repeat if needed: Some SABAs require more than one puff. Follow your doctor's instructions.
• Glucocorticoids

  • Used for long-term control of asthma sx, reducing inflammation in the airways. Not a rescue inhaler!

  Steps:

  Shake the inhaler

  blow out all the air from your lungs.

  If using a spacer, attach the inhaler and place the mouthpiece comfortably between your lips. If not using a spacer, put the mouthpiece directly in your mouth with a good seal. Press down on the inhaler as you start to breathe in slowly and deeply.

  Hold your breath for 10 seconds and then breathe out slowly.

  If using a spacer with a steroid inhaler, rinse your mouth with water after use to prevent thrush.
• Strategies to prevent candidiasis infections in the mouth (secondary to inhaled steroids)

  Teach patients to gargle and rinse the mouth with lukewarm water afterward to prevent the development of oral and fungal infections. 

  If a beta-agonist bronchodilator and corticosteroid inhaler are both ordered, the bronchodilator should be used several minutes before the corticosteroid to provide bronchodilation before the administration of the corticosteroid.
• Methylxanthines 

  • MOA: Cause smooth muscle relaxation by increasing cAMP, bronchodilation, and increased airflow.
  • Indication: Used in asthma (not first line)
  • Adverse effects: palpitations, tachycardia, Vtach, GERD, hyperglycemia, N/V
  • Nursing implications: Be aware of drug interactions with cimetidine, oral contraceptives, allopurinol, certain antibiotics, influenza vaccine, others. Cigarette smoking enhances xanthine metabolism
• Food to avoid while on theophylline/therapeutic range

  • Foods to avoid: 
  • Interacting foods include charcoal-broiled, high-protein, and low-carbohydrate foods
  • These foods may reduce serum levels of xanthines through various metabolic mechanisms

  Therapeutic range: Narrow therapeutic level 10-20 mcg/ml ( in clinical practice we keep at at around 5-15 to avoid toxicity
• Leukotriene receptor antagonist

  Prototype: 

  • Montelukast (Singulair) → approved for children too
  • Zafirlukast (Accolate)
  • Zileuton (Zyflo) 

  MOA: Non-bronchodilating, considered anti-inflammatory.

  They prevent leukotrienes from attaching to the receptors on the cells in the lungs and in circulation → inflammation in the lungs is blocked and asthma sx are relieved. 
• Montelukast

  • MOA: Inhibits leukotriene, prevent smooth muscle contraction of the bronchial airways. Decrease mucus secretion. Prevent vascular permeability. Decrease neutrophil and leukocyte infiltration to the lungs, preventing inflammation. 
  • Indications: Allergic rhinitis, prevention of asthma attack. NOT for rescue. 
  • Take at night 

  AE: Headache, nausea, diarrhea, dizziness, insomnia, altered liver function.
• Mast cell stabilizer: prototype

  Prototype: Cromolyn (Intal) and nedocromil (Tilade) 

  MOA: Inhibit mast cells from releasing histamine and other chemical mediators of inflammation thus preventing asthma attacks.

  Indications: Asthma prophy, NOT for acute asthma attack 

  AEs: Stinging or burning of the nasal mucosa, irritation of the throat, and nasal congestion.
• Ipratropium bromide (Atrovent) (LAMA)

  • MOA: Muscarinic antagonist (anticholinergic). Antagonizes Ach receptors → inhibits nasal/mucus secretions (nasal), bronchodilation (in lungs). 
  • Slow and prolonged action. 
  • NOT used for acute attacks alone. 
  • Indication: Relieve and prevent bronchospasms in asthma and COPD
• Ipratropium bromide (Atrovent) (LAMA)

  • AE’s: Irritation of the upper respiratory tract (cough, drying of the nasal mucosa, or hoarseness), palpitations, bitter taste (rinse mouth after use) 
  • Contraindication: Allergy to atropine, careful with angle closure glaucoma and BPH 

  Interactions: Avoid antidiabetic drug pramlintide - Serious or life-threatening GI symptoms.
• General teaching about antibiotics

  • Abx are only for bacterial infections 
  • Any time you put a patient on antibiotic we target an organism → This can cause superinfection , opportunistic infections
• Possible problems a/w use of antibiotic

  • Superinfection
  • Pseudomembranous colitis
  • Can have severe diarrhea, electrolyte imbalance, perforate the colon, and death
  • Secondary infection
  • Resistance
  • Food drug interaction
  • Host factors
  • Allergic reactions
  • We have to identify if the patient has an allergy and document what type of allergy they have 
  • If they have a true penicillin allergy - they wont be able to receive classes of meds like cephalosporin 

  Can't predict who will get it so we don't wanna overprescribe abxs.
• Indications for antibiotics (empiric vs. definitive, etc.)

  Empiric therapy - given when you suspect the patient has an infection but before the cultures are back (42-72 hours)

  Definitive  therapy - antibiotic therapy tailored to treat a specific organism

  Prophylactic therapy - treatment with antibiotic to prevent infection
• Therapeutic response occurs when the antibiotic is working effectively against the infection. 

  Subtherapeutic response - the antibiotic is not strong enough to conquer the bacteria → infection is not getting better
• Superinfection: signs and symptoms

  signs and symptoms of superinfection can include diarrhea, vaginal discharge, stomatitis, loose and foul-smelling stools, and cough.
• Penicillin 

  *Allergic reactions occur in 0.7 to 0.4% of treatment courses 🡪 Urticaria, pruritus, angioedema  (swelling of lips and tongue – ACE). Increased risk for being allergic to beta -lactam.  **Only those with a history of throat swelling or hives from penicillin should not receive  cephalosporins!  

  ***When used for strep throat need to make sure it is taken completely to avoid rheumatic fever,  valvular disease, and glomerulonephritis.  
• Sulfonamides 

  Sulfamethoxazole/trimethoprim (a nonsulfonamide antibiotic) known as Bactrim 

  • MOA: Bacteriostatic action, Prevent synthesis of folic acid required for synthesis of purines and nucleic acid, Do not affect human cells or certain bacteria, Only affect organisms that synthesize their own folic acid
  • Indications: Effective against gram negative and gram positive bacteria. Tx of UTIs 
  • Among others **
• Sulfonamides 

  Sulfamethoxazole/trimethoprim (Bactrim)

  • AE’s: 
  • Blood: Hemolytic and aplastic anemia, agranulocytosis, thrombocytopenia. 
  • Integumentary: Photosensitivity, exfoliative dermatitis, Stevens- Johnson syndrome, epidermal necrolysis. 
  • GI: Nausea, vomiting, diarrhea, pancreatitis
  • Other: Hepatotoxicity, convulsions, crystalluria (if patient is on NSAIDs), toxic nephrosis, headache, peripheral neuritis, urticaria, cough 
• Sulfonamides 

  Sulfamethoxazole/trimethoprim (a nonsulfonamide antibiotic) known as Bactrim 

  • Contraindicated: severe renal/liver disease, megaloblastic or folate deficiency anemia, Sulfa allergy.  
  • Caution: Pregnancy. 
  • ***Small theoretical cross reaction between sulfa allergy, NSAID, and diuretic (thiazide/loop)***
• Aminoglycosides: SE

  Aminoglycosides  - include gentamicin and neomycin (Neo-fradin)

  • They kill gram negative bacteria. 
  • AEs: Nephrotoxicity- check BUN, Cr; Ototoxicity - hearing loss, tinnitus. 

  Must monitor drug levels to prevent toxicities - peaks and trough levels (max and min conc)

  Minimum inhibitory concentration (MIC) - lowest amt of drug that will do the job