L46-48 Pulm Flashcards
What are the two categories of asthma?
- Intermittent
2. Persistent
What is the medication of choice for the treatment of bronchospasm?
Beta-2 adrenergic agonists (bronchodilators)
What are the selective short-acting beta 2-adrenergic agonists used for asthma?
- Albuterol
- Terbutaline
- Metaproterenol
- Bitolterol
What are the long-acting beta 2-adrenergic agonists used for asthma?
- Salmeterol
- Formoterol
- Vilanterol
What is the MoA of beta-2 agonists?
Stimulates adenylyl cyclase, increases cAMP in smooth muscle, leading to powerful bronchodilation
Inhibits release of mediators from mast cells
How are bronchodilators administered?
- Metered inhaler (faster, more potent, fewer side effects)
- Nebulizer (expensive, contamination, more consistent)
- Oral (slower, more side effects)
- Parenteral
What are side effects of bronchodilators?
- Skeletal muscle tremors
- Tachycardia
- Anxiety/restlessness/apprehension
Theophylline is a methylxanthine that inhibits phosphodiesterase and is a competitive antagonist for adenosine receptors. Why is it rarely used?
Frequent side effects (convulsions, tachycardia), drug interactions, limited effectiveness, risk of life-threatening complications from OD, narrow therapeutic window
What are the two muscarinic antagonists used to treat asthma? When are they used?
- Ipratropium
- Tiotropium
Patients who can’t tolerate beta 2 agonists
What is the MOA of muscarinic antagonists?
Competitively blocks muscarinic receptors in the airway, inhibit ACh, prevents bronchoconstriction
The side effects of muscarinic antagonists are minimal, but they can have ___-like effects at high dosages.
Atropine
What are the inhaled corticosteroids used to treat asthma?
- Beclomethasone
- Flunisolide
- Fluticasone
- Momentasone
- Triamcinolone
What is the oral corticosteroid used to treat asthma?
Prednisone
What is the IV corticosteroid used to treat asthma?
Methylprednisolone
What is the MOA of inhaled corticosteroids?
Reduce the synthesis of arachidonic acid by inhibiting phopholipase A2 activity; this inhibits the synthesis and release of leuktrienes and prostaglandins
How are inhaled corticosteroids used to treat asthma?
First line prophylactic therapy for persistent asthma
What are short-term side effects of oral corticosteroids?
Increased energy, insomnia, hunger, agitation, mood alteration
What are long-term side effects of oral corticosteroids?
Osteoporosis, cataracts, myopathy, HPA axis suppression, depression
What are side effects of inhaled corticosteroids?
Oropharyngeal candidiasis, vocal cord changes, nose bleeds, mucosal irritation
What is the MOA of Cromolyn and when is it used?
Decreases the release of histamine and leukotrienes; prevent symptoms before exposure to a trigger (exercise and cold asthma), alternative to low dose glucocorticoids - less effective, nebulizer, must be used 3-4x/day
What are the leukotriene antagonists?
- Montelukast
- Zafirlukast
- Zileuton
What is the MOA of the leukotriene antagonists?
Montelukast and zafirlukast are LT receptor antagonists. Zileuton is an inhibitor of 5-lipoxygenase. They all open narrowed airways, decrease inflammation and mucus production.
What are the side effects of leukotriene antagonists?
Mood alterations, depression, headache, nausea
When is Zileuton contraindicated?
Hepatic disease
What is Omalizumab and what is its MOA?
Monoclonal Ab to human IgE
Forms a complex with free IgE to lower serum levels; prevents IgE from binding to mast cells and releasing histamine and leuktorienes
Which treatment is used for symptom relief of bronchospasm in acute asthma attacks?
Short and long acting beta-2 agonists
___ is used in combination with corticosteroids in an inhaler for persistent asthma.
SABA/LABA
Which treatments are used as maintenance therapy for chronic asthma?
- Theophylline
2. Corticosteroids
What is unique about Theophylline?
Sustained release oral therapy
Which treatment is used alone or in combination with beta-2 adrenergic agonists in acute asthma?
Muscarinic antagonists
Which treatments are used prophylactically to prevent bronchospasm?
- Cromolyn
2. Leukotriene inhibitors
What are the side effects of Cromolyn?
Occasional coughing
How are allergies treated in young children?
- Comolyn sodium (nasal spray)
2. Second generation anti-histamines
What are the second generation anti-histamines?
Loratadine, Certirizine, Fexofenadine
Why should first generation anti-histamines be avoided in young children?
Sedative effects
How are allergies treated in older children and adults with mild symptoms?
- Second generation oral antihistamine
- Antihistamine nasal spray
- Glucocorticoid nasal spray
- Cromolyn nasal spray
What are the anti-histamine nasal sprays?
Azelastine, Olopatadine
What are the glucocorticoid nasal sprays?
1st generation (10-50% bioavailability) - beclomethasone, flunisolide
2nd generation (<2% bioavailability) - mometasone, fluticasone, ciclesonide
How are allergies treated in older children and adults with moderate to severe symptoms?
Glucocorticoid nasal sprays (most effecitve)
Failure to respond adequately - add a second agent
Concomitant asthma - add montelukast
Which agent is most effective for relief of nasal symptoms?
Glucocorticoid nasal sprays > oral antihistamines
What is the MOA of glucocorticoid nasal spray?
Down-regulate inflammation by inhibiting phospholipase A2
What are the side effects of glucocorticoid nasal sprays?
Nose bleeds, irritation of nasal mucosa
What are the drug interactions of glucocorticoid nasal sprays?
Fluticasone and strong inhibitors of CYP3A4 (ritonavir, itraconazole)
Why do first generation anti-histamines cause significant sedation?
Lipophilic and cross the blood brain barrier
What side effect are second generation anti-histamines associated with?
Weight gain
___ may decrease the effects of loratadine and fexofandine.
St. John’s Wort
What is the MOA of anti-histamines?
Block the binding of histamine to its receptor, reduced release of histamine and other mediators
What provides better symptom relief than antihistamines alone?
Oral antihistamine + decongestant
What are the side effects of decongestants?
HTN, insomnia, irritability, headache
What is the main first generation antihistamine?
Diphenhydramine (Benadryl)
What is the main second generation antihistamines?
Fexofenadine (Allegra), loratidine (Claritin), cetirizine (Zyrtec)
Broadly, what three things are immunosuppressant drugs used for?
- Prevent rejection of transplantation
- Treat autoimmunity
- Prevent host vs. graft/graft vs. host disease
What are the classes of immunosuppressant/immunoregulatory drugs?
- Ab for induction immunosuppression
- Glucocorticoids/steroids
- Proliferation inhibitors and anti-metabolites
- Immunophilin-binding drugs (inhibitors of T-cell signaling pathways)
- Immune checkpoint inhibitors
- Miscellaneous drugs used to treat relapsing-remitting MS
- Passive immunization Ig
Immunosuppressive therapy is aimed at preventing ___ rejection and prolonging graft survival.
Acute
What are the 4 general principles of transplantation and immunosuppressive therapy?
- Appropriate patient and donor preparation and selection (blood type, HLA-match)
- Multi-tiered approach to immunosuppression
- Potent initial immunosuppression (allows for lower doses of maintenance therapy)
- Reduce or withdraw drugs if toxicity > benefits
What are the general risks of immunosuppression?
Increased risk of infection and malignancy, post-transplant lymphoproliferative disorder
What are the two components of immunosuppressive therapy of organ transplant recipients?
- Induction therapy (intraoperatively and 3-7 days post-transplant)
- Maintenance immunotherapy (triple drug regiment post-op)
What are the components of the triple drug regimen used in maintenance immunotherapy?
- Glucocorticoid
- Cyclosporin or Tacrolimus
- Anti-proliferative drug
*Sirolimus/everolimus can replace #2 or #3
What is induction therapy?
Use of anti-lymphocyte Ab to acutely inhibit T-cell responses in the recipient at the time of transplantation
What are the two types of anti-lymphocyte antibodies used in induction therapy?
- Lymphocyte depleting
2. Functional inhibition
What are the 3 Ab induction reagents?
- Rabbit anti-thymocyte globulins (rATG)
- Alemtuzumab
- Basiliximab
How does rATG work?
Reacts with proteins expressed on lymphocyte surface (CD 2, 3, 4, 8, 11a), actively depletes lympohcytes from the blood and lymphoid organs
How does Alemtuzumab work?
Anti-CD52, actively depletes T cells by triggering Ab-mediated lymphocyte lysis
How does Basiliximab work?
Humanized Ab that binds CD25 (alpha-chain of IL-2R), inhibits T-cell proliferation (less effective than depleting Ab)
Generally, what are the adverse effects of the antibody induction reagents?
Cytokine release syndrome, prolonged leukopenia, increased infections
Which Ab induction reagent is well-tolerated but has more rejection than other agents?
Basiliximab
What are the key glucocorticoids?
Prednisone (pro-drug), Prenisolone (active)
What do steroids do?
Inhibit immune system, inhibit expression of pro-inflammatory genes, decrease # of circulating leukocytes
What is the MOA of glucocorticoids?
Diffuse into cells, bind their receptors in cytoplasm, promote receptor dimerization, nuclear translocation, active receptors bind to target genes and inhibit critical immunoregulatory genes
In addition to prevention of organ graft rejection, what else can steroids be used for?
High dose IV pulses: acute rejection episodes, GvHD in BMT, treatment of cytokine-release syndrome
Autoimmune/inflammatory disease: RA, SLE, MS, psoriasis, IBD, skin diseases, eye diseases, asthma, etc.
What are some of the serious AE associated with chronic treatment with glucocorticoids?
Hyperglycemia, HTN, hyperlipidemia, obesity, diabetes, osteopenia, cataracts, growth retardation, poor wound healing, mania and psychosis, increased risk of infection
What can happen if steroid therapy is stopped abruptly?
Acute adrenal crisis
What are the proliferation inhibitors and anti-metabolites?
- Azathioprine
2. Mycophenolate mofetil
Azathioprine is a pro-drug of ___.
6-mercaptopurine
What happens after 6-mercaptopurine is formed?
- Forms 6-TIMP (inhibits de novo purine biosynthesis)
- 6-TIMP forms 6-TGTP (inhibits CD28/Rac1 T-cell costimulation)
- 6-TGTP is incorporated into DNA, leading to apoptosis
All of these inhibit lymphocyte proliferation
When is Azathioprine indicated?
- Prophylactic prevention of graft rejection following organ transplantation
- Autoimmune diseases (RA, Chron’s, MS)
What are the AE of Azathioprine?
Diarrhea, nausea, vomiting, leukopenia, thrombocytopenia, hepatotoxicity, increased risk of infections/malignancy
What drugs interact with Azathioprine and how?
Allopurinol and feboxustat - xanthine oxidase inhibitors used in the treatment of gout.
By inhibiting xanthine oxidase, 6-mercaptopurine is elevated, leading to increased toxicity
Mycophenolate mofetil (MMF) is a prodrug of ___.
Mycophenolic acid (MPA)
What is MPA?
Non-competitive reversible inhibitor of inosine monophosphae dehydrogenase (IMPDH) type II
What is IMPDH type II?
Rate-limiting enzyme in the de novo synthesis of purine nucleotides (required for S phase); relevant because this selectively inhibits lymphocyte proliferation
When is MMF indicated?
On-label: prevent graft rejection following organ transplantation
Off-label: some autoimmune diseases (Phemphigus vulgaris, SLE, MG, psoriasis, Behcet’s disease, lupus nephritis)
What is the unique AE of MMF? What are the others?
Unique: progressive multifocal leukoencephalopathy caused by reactivation of JC virus
Other: diarrhea, nausea, vomiting, leukopenia, anemia, embryo/fetal toxicity, increased risk of infections/malignancies
When is MMF contraindicated and what drug is preferred in these situations?
Pregnancy, women of child bearing age, men who wish to become fathers; Azathioprine
What are 3 other anti-proliferative drugs used for immunosuppression?
- Methotrexate
- Cyclophosphamide
- Chlormabucil
Note: all contraindicated in pregnancy
What is the MOA of methotrexate?
Inhibition of dihydrofolate reductase indirectly inhibits purine/pyrimidine synthesis
Methotrexate is used for autoimmune diseases, especially ___.
RA
What is the MOA of cyclophosphamide?
Nitrogen mustard alkylating agent crosslinks DNA, RNA, and proteins
Cyclophosphamide is used to prevent acute graft rejection and GvHD, and is reserved for ___.
The most severe diseases (lupus nephritis, systemic vasculitis, etc.)
What is the MOA of chlormabucil?
Nitrogen mustard alkylating agent crosslinks DNA, RNA, and proteins
What are the two types of immunophilin-binding drugs?
- Calcineurin inhibitors
2. mTOR inhibitors
What are the two calcineurin inhibitors?
Cyclosporin and Tacrolimus
What are the two mTOR inhibitors?
Sirolimus and Everolimus
What are the indications of calcineurin inhibitors?
- Prevent solid organ rejection
- Prevent GvHD in BMT
- Autoimmune diseases (severe psoriasis, severe RA, SLE, IBD, nephrotic syndrome , eczema, dermatitis, eye conditions)
What is the MoA of cyclosporine and tacrolimus?
- Cyclosporin and tacrolimus readily enter the cell and bind to cyclophilin and FBKP, respectively.
- The complexes interact with calcineurin inhibiting its phosphatase activity and preventing the activation fo NFAT and subsequent expression of IL-2.
Cyclosporin and tacrolimus inhibit ___ of T-cell activation.
Signal 1
Cyclosporin binds to the immunophilin ___; tacrolimus finds to ___.
Cyclophilin; FKBP
Cyclophilin and FKBP are enzymes known as ___. What do they do? How is this involved in immunosuppression?
Peptidylprolyl isomerases (PPIases); catalyze isomerization of peptide bonds containing proline residues; it is unrelated
Discuss the PK of calcineurin inhibitors.
Extensively metabolized by CYP450 3A4
Poor oral bioavailability
Extensive distrubtion (lipophilic)
What are the most significant AE of calcineurin inhibitors?
Nephrotoxicity and HTN
Other: neurotoxicity/tremor, glucose intolerance, hyperlipidemia, hirsutism, hypertrichosis, alopecia, hyperK/Mg2+, gum hyperplasia, increased risk of infection/malignancy
What drugs increase the potential risk of toxicity of calcineurin inhibitors?
Inhibitors of CYP3A4 (grapefruit juice, azole anti-fungals, erytrho/clarithromycin, verapamil, diltiazem)
What drugs increase the potential risk of graft rejection when using calcineurin inhibitors?
Inducers of CYP3A4 (rifampin, carbamazepine, phenobarbital, phenytoin, St. John’s wort)
What is the MOA of mTOR inhibitors?
Bind FKBP, form complex which binds and inhibits the mTOR kinase complex downstream of IL-2 receptor. This inhibits IL-2 mediated signals
Sirolimus and Everolimus inhibit ___ of T-cell activation.
Signal 2
What are the indications of mTOR inhibitors?
- Prophylactic prevention of graft rejection
- Prevention of GvHD
- Included in coronary stents to inhibit re-stenosis by preventing cell proliferation
mTOR inhibitors are not recommended for liver transplants due to increased risk of ___.
Hepatic artery thrombosis
mTOR inhibitors are not recommended for lung transplants due to increased risk of ___.
Anastomotic dehiscence
What are the AE of mTOR inhibitors?
Hypertriglyceridemia, hypercholesterolemia, pulmonary edema/lung disease, increased risk new onset diabetes, anemia, thrombocytopenia leukopenia, decreased wound healing, increased risk of infection/malignancy, teratogenic effects
What are the drug interactions of mTOR inhibitors?
Similar to cyclosporine and tacrolimus
What are the immune checkpoint inhibitors for cancer immunotherapy?
Ipilimumab
Pembrolizumab/Nivolumab
What is Ipilimumab?
Monoclonal Ab specific for the CTLA4 protein expressed on activated T cells
What is CTLA4?
Negative regulatory protein that is upregulated on activated T cells that binds with high affinity to CD80 and CD86, thereby attenuating CD28-dependent co-stimulation and delivering an inhibitory signal to the T cell
What is the MOA of Ipilimumab?
Binding to CTLA4:
- Prevents CTLA4 from binding to CD80/86
- Prevents CTLA4 from delivering a negative signal
- Leaves CD28 co-stimulation intact
Enhanced T-cell activation
What are the indications of Ipilimumab?
Late stage melanoma
What are the AE of Ipilimumab?
Inflammation of skin, GI tract, liver, nerves, and adrenal glands
Treat with high dose steroids
What are the indications of pembrolizumab (Keytruda) and nivolumab?
Treatment of aggressive metastatic cancer (melanoma, colorectal, head/neck, hepatocellular carcinoma, renal cell caner, large cell lung cancer)
What is the MOA of pembrolizumab and nivolumab?
Ab specific for the negative regulatory PD1 protein expressed on T-cells
PD1 stimulation normally inhibits T-cell activation
These drugs block PD1/PD-L1 interactions, preventing negative signaling and leading to enhanced T cell immune responses against the cancer cell
What are the AE of pembrolizumab and nivolumab?
Lung, liver, colon, kidney, skin, pituitary, thyroid, and panreas immune reactions
Treat with high dose steroids
What are the drugs used in the treatment of Relapse-Remitting MS?
- Fingolimod
- Natalizumab
- Interferon beta
- Galtiramer acetate
#1/2 - effective but bad AE #3/4 - less effective but safer
What is the MOA of fingolimod?
Activates spingosine-1 phsophate receptor expressed on lympohcytes, sequestering them in the lymph nodes and preventing CNS access
What are the AE of fingolimod?
Risk of bradyarrhythmia and AV block, risk of varicella zorster virus infection
What is the MOA of natalizumab?
Anti-alpha4 integrin Ab blocks entry of lympohcytes into the CNS
What are the AE of natalizumab?
Increased risk of progressive multifocal leukoencephalopathy (PML)
What is the MOA of interferon beta?
Reduce entry of inflammatory cells into the CNS and reduce T cell activation
What is the MOA of glatiramer acetate?
Mixture of polymers of 4 amino acids found in myelin basic protein; promotes production of specific suppressor T cells that migrate to the brain and produce bystander suppression at sites of inflammation
What is IVIG and what is it used for?
Purified human Ig used to prophylactically provide passive immunity to individuals with underlying immunodeficiency diseases
What is hyperimmune Ig and what is it used for?
Similar to IVIG, but purified from individuals with high titers against a specific Ag or organism
Used for Hep B, CMV, rabies, tetanus, botulism, diphtheria, varciella zoster, snake/scorpion bites
What is Rho(D) Ig and what is it used for?
Ab specific for the D antigen on RBCs, used to prevent hemolytic disease of the newborn in Rh-negative women
Why is multi-drug therapy used to treat active TB?
- Enhance rates of response/cure
2. Reduce emergence of resistance
What are the 4 first line drugs used to treat TB, often used in combination?
- Isoniazid HCl (INH)
- Rifampin
- Ethambutol
- Pyrazinamide (PZA)
INH is a prodrug activated by ___.
Catalase peroxidase (TB katG gene)
INH targets the ___ gene product, which leads to fatty acid synthesis of cell wall mycolic acid.
inhA gene product
INH is ___ for replicating organisms and ___ for resting organisms.
Bactericidal; bacteriostatic
What are two mechanisms of resistance to INH?
- Mutations in the katG gene that prevent INH activation
2. Mutations in the inhA gene that allow cell wall synthesis to proceed
How is INH distributed?
Widely, includes CSF, particularly when inflammed
What are the AE of INH?
- Hepatotoxicity (sympomatic hepatitis in some)
- Neurotoxicity (peripheral neuritis)
- Hypersensitivity reactions (fever, rash, lupus-like, +ANA)
What reduces incidence of neurotoxicity in INH treatment?
Pyridoxine (vitamin B6) therapy
INH + ___ (drug) increases occurrence of hepatitis.
Rifampin
INH reduces clearance of ___, leading to toxicity.
Dilantin
INH decreases ___ levels and ___ activity.
Itraconazole; levodopa
What organisms does Rifampin target?
GP (Staph, etc.)
Rifampin is used as single drug therapy prophylaxis for ___.
Meningitis (N. meningitidis)
What is the MOA of Rifampin?
Inhibits DNA-dependent RNA polymerase, encoded by the rpoB gene
What causes Rifampin resistance?
rpoB mutations
Rifampin is ___ to all populations of organisms.
Bactericidal
Discuss the distribution of Rifampin.
Penetrates most tissues well, good CSF normally and when inflamed
What are the AE of Rifampin?
- Hepatotoxicity
- Red discoloration of body fluid (urine, tears, soft contacts)
- Acute renal failure, interstitial nephritis
- Influenza syndrome (more common with intermittent dosing)
- Thrombocytopenia
- Cholestatic jaundice
Rifampin is a heavy ___ of hepatic microsomal enzymes.
Inducer (accelerates clearance of these drugs)
What is the MOA of Ethambutol?
Inhibits TB arabinosyl transferase encoded by the embB gene, affecting cell wall synthesis; helper drug that inhibits resistance to other drugs
Ethambutol is ___ (static vs. cidal)
Static
Discuss the distribution of Ethambutol.
Good, except CSF levels (even when inflamed)
What are the AE of Ethambutol?
- Optic neuritis (blurred vision, central scotomata, red-green color vision loss)
- Peripheral neuropathy
What is the MOA of PZA?
Prodrug activated by TB pyrazinamidase, enocded by pncA
PZA is ___ (cidal vs. static).
Cidal
Discuss the distribution of PZA.
Good, including CSF
What are the AE of PZA?
- Hepatitis
- Skin rash, GI intolerance
- Increased serum uric acid levels (acute gout is uncommon)
What is the second line TB drug?
Streptomycin
What is the MOA of Streptomycin?
Inhibits protein synthesis by binding to the ribosome
What are the AE of Streptomycin?
- Ototoxicity
2. Nephrotoxicity
What is primary resistance?
Resistance acquired at infection (TB itself is drug resistant)
What is secondary resistance?
Resistance developed during therapy (from ineffective therapy)
The risk of evolution of resistance to two drugs is…
…the product of the risk of the development of resistance to each drug.
What is multi-drug resistant TB?
TB that is resistant to both INH and Rifampin
What populations have multi-drug resistant TB most commonly?
Patients with HIV
If the TB is resistant to rifampin, how does the therapy change?
Eliminates short-course (6 month), requires therapy for at least 18-24 months
(IPE)
What is extensively drug resistant TB?
Resistance to INH, Rifampine, FQs, 1 of 3 injectables (amikacin, kanamycin, capreomycin)
What is the initial phase and continuation phase of 6-month TB treatment?
Initial: RIPE
Continuation: RI
How is INH mono-resistant TB treated?
REP for 6 bmonths
How is PZA monoresistant TB treated?
9 months of therapy
What is the fundamental strategy of treating TB?
- Use at least 2 drugs to which the patient’s TB strain is susceptible
- Use only drugs that have never been used in the patient before
How is LTBI treated?
- INH monotherapy for 9 months
- Rifampin 4 month daily therapy (more expensive but better adherence)
- INH + Rifapentene for 3 months, 12-doses, one weekly, DOT regiment
How is M. avium (intracellular) treated?
Rifampin, Ethambutol + clarithro/azithromycin for 1 year after sputum culture conversion to negative
Resistant to INH and PZA
How is M. kansasii treated?
RIE for 1 year after sputum culture conversion to negative
Resistant to PZA
How is rapidly growing mycobateria treated?
Resistant to all first line
1-3 months of cefoxitin/amikacin or imipenem/amikacin
12-18 months of clarithro/azithro + FQ
What drugs are active against TB only?
INH
PZA
Which drugs are active against NTM only?
Clarithro
Azithro
What drugs are active against TB and NTM?
Rifampin
Ethambutol
FQ
AG
How is Paucibacillary leprosy treated?
Rifampin + Dapsone daily for 12 months
How is Multibacillary leprosy treated?
Rifampin + Dapsone + Clofazimine daily for 24 months