Exam II Flashcards
List and explain the 4 defensive factors which protect the stomach and duodenum from self-digestion.
Mucus – forms a barrier to protect underlying cells from gastric acid and pepsin.
Bicarbonate – neutralizes any acid which penetrates the mucus.
Blood flow – maintains integrity or health of the mucosa
Prostaglandins – Stimulates mucus and bicarbonate, vasodilates blood vessels, suppresses gastric secretion
List and explain 5 aggressive factors which predispose the stomach and duodenum to ulcerations.
Helicobacter pylori (H. pylori) – gram-negative bacillus which lives between the mucus layer and the mucosa. Produces CO2 and ammonia from urea which damages the mucosa.
NSAIDs – decreases the production of prostaglandins which decreases blood flow, decreases bicarbonate and mucus secretion, and increases gastric acid.
Gastric Acid – injures cells of the mucosa and activates pepsin.
Pepsin – breaks down protein of the gut wall.
Smoking – delays healing of ulcers and increases risk of recurrence.
What are three mechanisms of action for antacids?
Binds gastric acid and forms a neutral salt, decreases pepsin if pH > 5, and stimulates prostaglandins.
How are antacids administered in relation to meals, sleep, or other drugs? If not eating, how often are they given?
1 and 3 hrs after meals and at bedtime, 1 hour before another drug, or every 2 hours if not eating
Which antacids can cause complications in heart failure and renal disease?
Aluminum hydroxide and sodium bicarbonate – heart failure, magnesium hydroxide – CNS toxicity in renal patients
How do histamine2 receptor antagonists work?
Block H2 receptors on parietal cells which suppress gastric acid secretion and decrease the hydrogen ion concentration in gastric acid.
How are histamine2 receptor antagonists administered in relation to meals?
May be taken without regard to meals, except take Tagamet with food
Which histamine2 receptor antagonist is noted for drug-drug interactions caused by inhibition of hepatic drug-metabolizing enzymes?
cimetidine (Tagamet)
Which histamine2 receptor antagonist is known for its ability to block androgen effects?
cimetidine (Tagamet)
Proton-pump inhibitors may decrease the absorption of antifungals by what action?
Decreased gastric acid production
When is esomeprazole/nexium given?
Esomeprazole (Nexium) is given one hour before a meal
How long does it take for full recovery of the H+, K+-ATPase pump after stopping a proton pump inhibitor?
Why? How long for partial recovery?
Weeks due to irreversible inhibition. 3-5 days.
Why is misoprostol (Cytotec) used?
What are the mechanisms of action?
Prevention of NSAID-caused gastric ulcers. Stimulates the secretion of mucus and bicarbonate, vasodilates blood vessels, suppress gastric acid secretion. Replaces prostaglandins.
Why is misoprostol (Cytotec) not given during pregnancy?
Stimulates uterine contractions.
How does sucralfate (Carafate) work? When should it be given?
Polymerization and cross-linking occurs when the pH is < 4. It adheres to the crater for 6 hours. Given on an empty stomach.
How many hours must elapse between an antacid and sucralfate (Carafate)? Between other drugs and sucralfate (Carafate)?
1 hour between an antacid and sucralfate.
2 hours between drugs and sucralfate.
In order to kill Helicobacter pylori, what combination of drugs is given?
2-3 antibiotics with a proton pump inhibitor or histamine-2 receptor antagonist
How does bismuth (Pepto-Bismol) work? What are two common side effects?
Disrupts the cell wall of H. pylori, inhibits urease, and keeps H. pylori from adhering to the mucosa. Black tongue and stools.
At what pH will pepsin be decreased?
> pH 5
What is the preferred drug category for the prevention of NSAID-induced ulcers?
Proton Pump Inhibitors
What are two signs of gastrointestinal bleeding?
Black, tarry stools and coffee-ground vomitus.
What is the acid-neutralizing capacity (ANC)?
The number of mEq of hydrochloric acid that is neutralized by a given amount of the antacid.
What are MDIs and how should they be used?
Metered-dose inhalers. Small, hand-held, pressurized devices. Begin slow inhalation before activation, hold medicine in lungs for 10 seconds, and wait 1 minute between activations.
What are SMIs and how should they be used?
Soft mist inhalers. Begin slow inhalation, hold medicine in lungs for 10 seconds, and wait 1 minute between activations.
What is the advantage of DPIs?
Disadvantage? How fast should the patient inhale?
No hand-lung coordination needed, breath-activated. Must have adequate inspiratory flow to inhale powder. Inhale rapidly.
What are SVNs and how are they used? What are the advantages?
Small volume nebulizers. Converts a solution into a mist. Does not require timing of dose with inhalation, rapid deep inspiration, or hand strength.
List three ways glucocorticoids treat asthma.
Suppress inflammation and bronchial reactivity, decrease mucus production, increase number and responsiveness of beta-adrenergic receptors.
What is the first-line treatment for moderate to severe persistent asthma?
Inhaled glucocorticoids
Discuss the proper way to administer inhaled glucocorticoids. Why?
Gargle & spit after use. Use the beta-adrenergic inhaler first if one is used. The beta-adrenergic inhaler opens the airways so that the glucocorticoid can penetrate deeper into the lungs. Gargling and spitting decreases the chance of an oropharyngeal infection.
Why might oral glucocorticoids be necessary during stress even if asthma symptoms are controlled?
May need to supplement because stressful events require bursts of steroids. The patient may develop adrenal crisis without supplementation.
How does montelukast (Singular), a leukotriene modifier, work?
Blocks leukotriene receptors.
What are four mechanisms of action for leukotriene modifiers?
Bronchodilation, decreased mucus, decreased edema, and decreased eosinophilic infiltration
How does Cromolyn, a mast cell stabilizer, work?
Prevents mast cells from lysing and releasing histamine and other mediators.
How long must mast cell stabilizers be used to obtain a therapeutic effect?
May take several weeks.
How does omalizumab (Xolair) work? Why are patients asked to stay in the clinic after injections?
Myoclonal antibody binds free IgE so that it cannot bind to mast cells and cause their lysis. Risk for anaphylaxis.
Why are beta2-adrenergic agonists used?
Relieve bronchospasm and prevent exercise-induced bronchospasm.
What are the three mechanisms of action for beta2-adrenergic agonists?
Bronchodilation, suppression of histamine release, increased ciliary motility.
What is the difference between short-acting and long-acting beta2-adrenergic agonists?
Short-acting: lasts 3-5 hrs, immediate effect, used for relief of bronchospasm and before exercise.
Long-acting: given every 12 hrs, used to prevent bronchospasm.
Discuss the adverse effects of beta2-adrenergic agonists.
Tachycardia, angina, tremor, hypokalemia, nervousness, insomnia, seizures, paradoxical bronchospasm.
Discuss three drug-drug interactions of beta2-adrenergic agonists.
Decreased potassium levels with diuretics, glucocorticoids, and methylxanthines. Beta-blockers block their therapeutic effects. Use of long-acting inhaled glucocorticoids may protect against increase in asthma-related deaths with inhaled long-acting beta2-adrenergic agonists.
Explain how anticholinergic inhalers work. List three anticholinergic inhalers.
Interrupt parasympathetic response causing bronchodilation and decreased mucus.
Atrovent (ipratropium)
Spiriva (tiotropium)
Tudorza Pressair (aclidinium)
How many minutes should elapse between 2 inhalations of a beta-adrenergic agonist? How long should the patient hold his breath? In what order should you have the patient take two inhalations of an inhaled steroid and 2 inhalations of a beta-adrenergic agonist inhaler?
1 minute
Hold breath for 10 seconds
2 inhalations of beta-agonist, then 2 inhalations of inhaled steroid.
How many times per week can a patient have symptoms and still be classified as mild intermittent asthma? How many night-time symptoms in a month?
< 2 /week
< 2/month
A patient with daily asthma symptoms is classified as having what type of asthma?
Moderate persistent
Explain the PEF zone system. If a patient’s personal best is 1000 and the PEF drops to 600, what zone is he in? What drug should he use?
Yellow 50-80%.
Use short-acting beta agonist.
In conscious persons with severe asthmas exacerbations, which drugs should be administered first?
Beta-agonist and ipratropium (Atrovent) inhalations in a SVN
What drug categories are used to maintain patients who have COPD?
Long-acting beta2-adrenergic agonists or anticholinergic inhalers.
What drugs categories are used initially for acute exacerbations of COPD?
Short-acting beta2-adrenergic agonists alone or with an anticholinergic inhaler.
What two drugs may be added for control of severe COPD?
Longterm inhaled glucocorticoids and Roflumilast (Daliresp)
What fasting and casual plasma glucose levels suggest diabetes mellitus?
Fasting: > 126 mg/dL
Casual: > 200 mg/dL
What are the preprandial and postprandial targets for patients with DM/ What is the target for A1c?
Preprandial: 70-130 mg/dL
Postprandial: < 180 mg/dL
A1c: < 7% (154 mg/dL)
What is an electrolyte indication for insulin?
Hyperkalemia
How are insulin durations changed?
Change amino acid sequence or add a protein.
What are the mechanisms of action of insulin?
Transports glucose, amino acids, nucleotides, and potassium into cells. Promotes synthesis of glycogen, proteins, and triglycerides.
What are two contraindications for insulin?
Hypoglycemia and hypokalemia.
How long may opened insulin vials be stored at room temperature?
1 month.
When drawing up a short-acting insulin and NPH insulin in the same syringe, which is drawn first? Which short-acting insulins may be mixed with NPH insulin?
Short-acting insulin.
Regular insulin and the rapid-acting insulin analogs – insulin lispro, insulin aspart, & insulin glulisine
Are all clear insulins short-acting? Explain.
No. Insulin detemir (Levemir) and insulin glargine (Lantus) are long-acting insulins respectively and are clear.
How can you minimize lipohypertrophy with insulin injections?
Use the same site only one time per month and keep the sites one inch apart.
Which of the insulins may be given IV?
Insulin lispro (Humalog), insulin aspart (Novolog), insulin glulisine (Apidra), regular insulin (Humulin R or Novolin R).
When should short, rapid-acting insulin analogs be given?
5-15 minutes before meals
When should regular insulin be given?
30 minutes before meals
When is NPH insulin given when given mixed with regular insulin?
30 minutes before breakfast and dinner
How often is insulin glargine (Lantus) given? When is the drug usually dosed?
Once per day. Same time each day.
Why are beta-blockers not recommended to be given to patients with diabetes?
Beta-blockers mask the signs of hypoglycemia and also prevent glycogenolysis, which allows glycogen to breakdown into glucose (necessary to prevent hypoglycemia).
What are the symptoms of hypoglycemia?
Tachycardia, palpitations, sweating, nervousness, headache, confusion, drowsiness, fatigue. Also convulsions, coma, death.
What is the treatment for hypoglycemia in alert patients? What about those taking alpha-glycosidase inhibitors?
Glucose tablet, orange juice, sugar cubes, honey, corn syrup, nondiet soda. Must use glucose tablets if take alpha-glycosidase inhibitors that prevent the breakdown of sugars into monosaccharides.
What drug is administered to unconscious patients with hypoglycemia? How does it work? What works faster?
Glucagon. Breaks down glycogen into glucose and accelerates hepatic gluconeogenesis. IV glucose.
What are the mechanisms of action of metformin (Glucophage), a biguanide?
Sensitizes cells to insulin and decreases liver glucose production. Also slightly inhibits intestinal absorption of glucose.
What procedure is used for patients who use metformin (Glucophage) who are undergoing tests with radiocontrast dye?
Stop drug 1-2 days before procedure, drink lots of fluids, restart drug if BUN, Cr have normalized 48 hours after the procedure.
What are the mechanisms of action of second-generation sulfonylureas? What occurs over time?
Stimulates the release of insulin from pancreatic beta cells. Lose effectiveness over time.
What allergic contraindication do sulfonylureas have?
Sulfa
What is adverse effect occurs with sulfonylureas and alcohol?
Dilsulfiram-like reaction
What is the difference in mechanisms of action between sulfonylureas and glinides?
Glinides must be given immediately before meals, because their action is much faster than sulfonylureas.
What is the mechanism of action of thiazolidinediones?
Sensitizes cells to insulin and decreases liver glucose production.
What is the black box warning for thiazolidinediones? Signs to look for?
Avoid with severe heart failure due to water retention. Shortness of breath with exertion, crackles, chest pain, restlessness, changes in level of consciousness, increasing weight.
What is the mechanism of action of alpha-glycosidase inhibitors?
Prevents breakdown of carbohydrates into monosaccharides.
What adverse effect may occur with gliptins, incretin mimetics, and amylin mimetics?
Pancreatitis.
What drug interactions may occur with gliptins, incretin mimetics, and amylin mimetics?
Hypoglycemia if taken with other antidiabetic drugs. Slows absorption of other drugs.
How does canagliflozin (Invokana), a sodium-glucose co-transporter 2 inhibitor, work?
Blocks the reabsorption of glucose from the tubular urine back into the kidney’s bloodstream.
What is selective toxicity? Why is it important?
Injuring a target cell or organism without injuring other cells or organisms in intimate contact with the target. Makes antibiotics safer.
What is the difference between bactericidal and bacteriostatic?
Bactericidal – kills bacteria
Bacteriostatic – slows growth, phagocytes eliminate bacteria
What are ranges and chances of drug resistance with narrow-spectrum and broad-spectrum antibiotics?
Narrow: smaller range
less resistance
Broad: larger range
more resistance
What is acquired resistance? What are four ways bacteria become resistant to antibiotics? How do we lessen the chance for resistance?
Bacteria become less susceptible or lose sensitivity to drug.
1) Reduce drug concentration at sites, 2) Alter drug receptors, 3) Synthesize an antagonist, & 4) Produce drug-metabolizing enzymes.
Treat infection, not colonization, and use correct drug in correct concentration for entire course of therapy.
What is the difference between the MIC and MBC?
MIC – amount of drug required to halt growth
MBC – amount of drug required to kill 99.9%
Explain the importance of conjugation. What bacteria are most affected?
Conjugation allows the DNA code for drug resistance to be passed to other bacteria. Gram negative bacteria.
What are two examples of suprainfections?
Candidiasis (yeast infection), Clostridium difficile infection (CDI) – 3 or more unformed stools in 24 hours with C. difficile or toxin from C. difficile in stools.
What is the difference between an additive and potentiative effect?
Additive – sum of the effect
Potentiative – greater than the sum of the effects
How do penicillins kill bacteria?
Disrupts cell wall (inhibits cross-linkages between peptidoglycan strands and lyses cell wall bonds)
What is the major adverse effect of penicillins?
Allergic reactions
What are some common signs and symptoms of anaphylaxis and serum sickness to penicillins?
Laryngeal edema, bronchoconstriction, severe hypotension, nausea and vomiting, tachycardia
Rash, hives, pruritis, arthralgias, fever
Which three penicillins can be taken with food?
Penicillin V or VK, Amoxicillin, Augmentin
Why is Penicillin G given IM?
Destroyed by gastric acid
What lab abnormality can occur with Penicillin G or V when administered with potassium supplements?
Hyperkalemia
What types of enzymes can destroy the penicillin molecule?
General beta-lactamases and penicillinases. Cephalosporinases deactivate cephalosporins.
What is the advantage of Nafcillin over other penicillins?
Penicillinase-resistant
Amoxicillin has what kind of bacterial spectrum?
Broad-spectrum
How does clavulanic acid prevent amoxicillin from being deactivated?
Clavulanic acid inhibits beta-lactamase
What are other beta-lactam antibiotic groups that have cross-allergenicities with penicillins?
Cephalosporins, carbapenems
How do cephalosporins kill bacteria?
Inhibits cell wall synthesis
Each subsequent generation of cephalosporins show more activity against what type of bacteria? How does each subsequent generation penetrate into the cerebral spinal fluid?
Gram negative bacteria and anaerobes, more resistant to beta-lactamases.
Each subsequent generation is more likely to reach the cerebral spinal fluid.
What percentage of penicillin-allergic patients will have an allergic reaction to a cephalosporin?
< 1%
What is the adverse effect seen with some cephalosporins and alcohol?
Antabuse-like effects: weakness, pulsating headache, chest pain, abdominal cramps
What is the drug interaction is seen between IV calcium and IV cephalosporins in neonates?
Lung and renal precipitates.
How does vancomycin kill bacteria? What bacteria does it kill?
Inhibits cell wall synthesis. Gram-positive bacteria.
For what types of infection is vancomycin reserved? How is it given for CDI?
Severe C. difficile infections (CDIs), MRSA, & Staph. Epidermidis. Must be given PO for CDI, because cannot cross between GI tract and bloodstream.
What are the signs and symptoms of Red Man Syndrome seen with the rapid infusion of vancomycin?
Red rash, hives, flushing, and pruritis on face & upper body. Hypotension, tachycardia. From histamine release, NOT an allergic reaction.
Creatinine (Cr) is monitored with vancomycin therapy to avoid what? What is an indication for stopping vancomycin?
Renal failure. Stop if Cr rises 50%.
Aztreonam is used to treat what type of infection? Why?
Gram-negative aerobic bacteria. Only attaches to PBPs on gram-negative aerobic bacteria.
How do tetracyclines inhibit the replication of bacteria?
Inhibits protein synthesis at ribosomes
How long should a patient wait after taking tetracycline before he has a glass of milk?
2 hours
Why are tetracyclines avoided in children younger than 8 years of age?
Discoloration and hypoplasia of teeth
What precautions should patients take with tetracycline?
Sun protection for photosensitivity. Take with a full glass of water to prevent esophageal ulcerations.
How does erythromycin increase the chance of drug interactions?
Inhibits hepatic drug metabolism by P450 system.
What is the major risk of drug interactions with erythromycin?
QT prolongation, which places person at risk for Torsades de Pointes,
How does erythromycin inhibit the replication of bacteria?
Inhibits protein synthesis at ribosomes
What are common adverse effects of erythromycin? How can this be mitigated?
Nausea, vomiting, diarrhea, epigastric pain. Give ethylsuccinate or enteric-coated tablets with food.
How does clarithromycin (Biaxin) inhibit the replication of bacteria?
Inhibits protein synthesis at ribosomes
Which macrolide does not inhibit hepatic enzymes? What drug interaction is still significant with this drug?
Azithromycin (Zithromax). Raises warfarin (Coumadin) levels.
Linezolid is used primarily for what 2 bacteria?
Vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA)
How do sulfonamides inhibit replication of bacteria?
Competes with PABA in synthesizing folic acid and inhibits enzyme (dihydrofolate reductase) used to synthesize folic acid
Why are sulfonamides contraindicated for infants less than 2 months old?
Kernicterus
Which antibiotic drug class is avoided in patients with G6PD deficiency? Why?
Sulfonamides may cause hemolytic anemia.
What drugs should be used with caution if the person in allergic to sulfonamides? Should a person with anaphylaxis try these drugs?
Sulfonylureas (oral antidiabetic drugs), loop diuretics, thiazide diuretics, and Celebrex (COX-2 inhibitor). Absolutely not due to a higher risk of hypersensitivity.
Why should a patient stop using a sulfonamide with a blistering, sunburn-like rash? What other skin reaction may occur
Risk for Stevens-Johnson Syndrome. Photosensitivity.
How do fluoroquinolones kill bacteria?
Inhibit synthesis of nucleic acids
Why should fluoroquinolones not be used in patients under the age of 18?
Tendon injury
For what type of bacteria are aminoglycosides given?
Aerobic gram negative bacilli
Fluoroquinolones are ordered to be given in the morning with a multivitamin with minerals. Why is this contraindicated?
Calcium, aluminum, magnesium, iron, zinc may combine with the fluoroquinolone and prevent its absorption. Give fluoroquinolones 2 hours before or 6 hours after minerals. Give fluoroquinolones on an empty stomach.
Ciprofloxacin (Cipro) is given for what common disease processes?
UTIs, enteric organisms.
What are the two mechanisms of action for aminoglycosides?
Inhibit protein synthesis at ribosomes and insert abnormal proteins into the cell wall.
Instead of keeping the serum drug levels above the MIC (minimum inhibitory concentration), how do aminoglycosides kill bacteria?
Concentration-dependent kill with post-antibiotic effect.
Discuss the distribution of aminoglycosides.
Unable to cross cell membranes. Not absorbed orally and does not cross blood-brain barrier.
What two organs can be damaged by aminoglycosides?
Ears, kidneys
When are gentamicin peak and trough levels drawn?
Multiple doses: Peak level 30 min after IM or after 30-min IV infusion. Trough level immediately before next dose.
Daily dose: Trough level 1 hr before next dose. No need for peak level.
What two antibiotics are reserved mainly for anaerobic bacteria?
Clindamycin (Cleocin) and metronizadole (Flagyl).
What viruses does acyclovir (Zorivax) treat? Does it cure the disease?
Herpes simplex viruses (HSVs) – cold sores and genital infections, varicella-zoster virus (VZV) – chickenpox and shingles. The drug manages the symptoms, but does not cure or prevent transmission.
When are omeprazole/Prilosec and iansoprazole/Prevacid given?
Directly before a meal
When are proton pump inhibitors given?
Other than nexium, Prilosec, and Prevacid, given at any time
