-
iii) Anticholinergic – ipratropium (Atrovent®)
- (1) Bronchodilator
- (a) Blocks muscarinic receptors
- (b) Not drying
- (i) Probably due to poor lipid solubility
- (2) Systemic side effects NOT SEEN SO FAR
- (3) Currently recommended for COPD but not asthma
- (a) May have value in asthma as adjunct
-
2) Respiratory drugs with Anti-inflammatory Effects- what are they (3 types) and when would they be used?
- a) Asthma Prophylactics – cromolyn (Aaranene®, Intal®), nedocromil (Tilade®). AKA: Mast Cell Stabilizers (Basophil)/ Histamine Release Inhibitors
- i) Therapeutic Uses: helps prevent asthma attack from occurring – cannot treat symptoms once they have appeared. Takes 2 weeks to become effective w/ 4-6 doses/day
- (1) Atopic asthma
- (2) Exercise induced asthma
- (3) Some cases of intrinsic asthma
- (a) Not used for bronchitis/emphysema
- (b) Advantage: no cardiac stimulation
- ii) MOA: Prevents release of histamine & other mediators
- (1) Is therefore “anti-inflammatory”
- (2) Interferes w/ bronchoconstriction that is histamine based
- iii) Caution
- (1) Inhalation occasionally causes bronchospasm, throat irritation, headache and unpleasant taste
- b) Leukotriene Receptor Antagonist (/Modifiers): montelukast (Singulair®), zafirlukast (Accolade®), zileuton (Zyflo®)
- i) Anti-inflammatory agents
- (1) For prophyllaxis only – NOT A “RESCUE” drug
- (a) Efficacy similar to cromolyn but more side effects
- ii) MOA:
- (1) Prevents leukotrienes form causing inflammation
- iii) Side Effects & Cautions
- (1) Headache
- (2) GI upset
- (3) Liver enzyme changes
- (a) Inhibits P450 enzymes so decreases metabolism of many other drugs
- c) Corticosteroids: Inhaled or Systemic
- i) Used only if other therapy doesn’t control symptoms
- ii) Positive interaction of inhaled corticosteroids and long acting sympathomimetics
- iii) Corticosteroid available as aerosol, talbets, and injections
- iv) Note: when these medications are needed, side effects of inhalers are much more acceptable than consequences of non-treatment
- v) Therapeutic Uses
- (1) Asthma & other severe COPD
- (2) Status asthmaticus (associated w/ bronchospasms)
- vi) MOA:
- (1) Suppression of antibody formation (including IgE responsible for allergy attacks)
- (2) Increases cyclic AMP which is needed for bronchodilation
- (3) Decreases cyclic GMP which causes bronchoconstriction
- vii) Side Effects
- (1) Local (w/ inhaler use)
- (a) Hoarseness, dry mouth, local infections in mouth and pharynx
- (2) Systemic (minimized by inhaler)
- (a) Irreversible
- (i) Osteoporosis (Ca++, protein, vitamin D helps), cataracts, stunting of growth in children
- (b) Reversible
- (i) Proneness to infections. Poor wound healing (including proneness to ulcers) (vitamin C helps), salt and water retention, signs of CNS stimulation (restlessness, insomnia, even manic states including depressive episodes in some individuals)
- viii) Cautions:
- (1) Rebound: Drug must be withdrawn slowly – body has decreased capacity to produce its own glucocorticoids. (Also must gradually switch to inhaler from oral forms of medication)
- (2) During times of stress, patient may need extra glucocorticoid
- (3) Full effect of steroid therapy may take 2-4 weeks to be seen
- ix) Warning: Corticosteroid inhaler is not for treatment of acute attacks (not to be confused w/ catecholamine inhaler)
-
3) Goal of treatment for Asthma? What are the rescue drugs vs. drugs for chronic therapy?
- a) Goal:
- i) Anti-inflammation
- ii) Bronchodilators
- b) Rescue drugs
- i) Sympathomimetics
- ii) Xanthines
- c) Drugs for chronic use
- i) Asthma prophylactic – cromolyn
- ii) Leukotriene Receptor Antagonist
- iii) Corticosteroids
-
4) Anti-tussives- Narcotic vs Non-narcotic
- a) Narcotic Antitussives – (Codeine, etc)
- i) MOA:
- (1) Depresses cough center in medulla of central nervous system
- ii) Side Effects & Cautions:
- (1) Potential for abuse limits usefulness of narcotic antitussives
- (2) Constipation
- (3) Depress respiration
- (4) Cause drug dependency
- b) Nonnarcotic Antitussives – (Usually fewer GI symptoms)
- i) MOA:
- (1) Some are peripherally acting
- (a) Ex: benzonatate (Tessalon®) –reduces activity of lung stretch receptors, or benzocaine, a topical anesthetic whose usefulness has not been established
- (2) Many act centrally as do the narcotics
- (a) Do not have narcotic side effects
- (b) Dextromethorphan- half as potent as codeine, no prescription necessary = an isomer of codeine that has no analgesic or addictive properties
- ii) Side Effects & Cautions
- (1) Skip- not serious- sometimes have atropine-like side effects, i.e. dry mouth, nausea and vomiting, etc
-
5) When do you treat a cough with an anti-tussive and when don’t you treat with an anti-tussive?
- a) Therapeutic Uses
- i) Preventing coughing
- (1) Only when cough is nonproductive, exhausting, or very painful
- b) Cautions:
- i) COPD
- (1) Asthma
- (2) Chronic bronchitis
- (3) Bronchiectasis
- (4) Cystic fibrosis (congenital disease w/ dysfunction of exocrine glands
- (a) In lung, overproduction of viscid mucus)
- c) Use of antitussive is 2ndary to treatment of source of cough
- i) Ex: in some asthmatics, cough is primary symptom
- (1) –would use bronchodilation, before an antitussive
-
6) What is an expectorant, a demulcent
- a) Demulcents
- i) –agents w/ a soothing effect (gargles, lozenges, syrups, even steam treatment)
- ii) Therapeutic Uses:
- (1) For cough & throat irritation
- iii) MOA:
- (1) Protects respiratory lining from irritation & contact w/ air
- iv) Cautions- none
- b) Expectorant
- i) –increase secretion of mucus I bronchi or modify it of reduce viscosity
- ii) 1st Treatment:
- (1) Steam & drink plenty of fluid (2 cups/hour)
- iii) Therapeutic Uses:
- (1) Asthma or other COPD (viscous mucus is the obstruction)
- (2) Bronchitis
- (3) Pneumonia
- (4) Coughs
- iv) MOA:
- (1) Make secreation more fluid so can be moved (i.e. makes coughing more productive)
- v) Side Effects
- (1) Usually specific to drug used – we won’t discuss
-
7) Nasal decongestants- what are the 3 types?
- a) Adrenergic agents
- i) Better than antihistamines for colds, useful for allergy stuffiness too
- ii) MOA: nasal vasoconstriction
- iii) Caution: habituation occurs (rebound)
- b) Antihistaminics
- i) Ok for allergy, may help relieve cold symptoms
- ii) (vs inflammation)
- c) Intranasal Steroids – for allergy (- immune system= - swell= -congestion)
- i) May increase risk of thrush & prevent healing of damage nasal mucosa
-
8) Histamine antagonizing drugs- what are they? What are the uses?
- a) Histamine:
- i) H1 receptors
- (1) Contraction of bronchial & intestinal smooth muscle
- (2) Dilation of arterioles & capillaries and increase permeability
- ii) H2 receptors
- (1) Increase gastric acid secretion
- b) General approaches to therapy
- i) Produce opposite effects as histamine (epinephrine)
- (1) Good for counteracting symptoms of reaction that has occurred
- (a) Only minor effect on histamine
- ii) Prevent histamine reaction = “antihistamine”
- (1) Histamine antagonist is a better term
- (2) Compete w/ histamine for H1 & H2 receptor sites
- (3) Most antihistaminics are H1 antagonists
-
9) Uses for H1 vs H2 antagonizing drugs
- a) H1 Antagonists “Antihistamines” – (these are the classical “antihistamine”
- i) 1st Generation types bind both centrally (CNS effects) & peripherally
- (1) More sedating but also more useful as sedative, for motion sickness, or in special cases for treating Parkinson’s
- (2) Ex: chlorpheniramine (Chlortrimeton®), clemastine (Tavist-D®), promethazine (Phenergan®)
- ii) 2nd Generation types
- (1) Less drowsiness
- (2) These newer agents can produce adverse cardiovascular effects (hypo- or hyper-tension, syncope, tachycardia)
- (3) Ex: azelstine (Asteline®), cetirizine (Zyrtec®), fexofenadine (Allegra®), and loratadine (Claritin®)
- iii) Therapeutic Uses
- (1) Antagonize allergic reactions (hives, watery eyes, stuffy nose – but NOT asthma!)
- (a) Prevent more symptoms from occurring
- (b) Less effective than epinephrine at counteracting reaction that has already occurred
- (i) Mechanism:
- 1. Besides preventing action of histamine, acts as mild sedative so more able to ignore distressing symptoms
- (2) Motion sickness
- (a) Not very effective at controlling nausea of other origins
- (i) –meclizine (Antivert®)
- 1. Mechanism:
- a. Appear to depress CNS & decrease sensitivity of inner ear
- iv) Side Effects: Chemical similarity to some antipsychotics & to atropine
- (1) Antipsychotic-like: drowsiness, sedation, dizziness
- (a) In others may cause agitation and hallucinations
- (b) Higher therapeutic doses are usually sedating
- (2) Antimuscarinic (atropine-like): dryness of mouth, blurred vision
- v) Cautions:
- (1) Potentiate other sedative-hypnotics, tranquilizers, and alcohol
- (2) Avoid use in asthmatics (drying of bronchiole secretions)
- (a) Asthma prophylactic cromolyn prevents the release of histamine by blocking degranulation of mast cells
- (b) A similar agent lodoxamide is marketed in eye solutions for eye allergies
- (c) Neither agent is an antihistaminic that competes for H1 receptor sites
- (3) Do periodic blood tests (check for blood dyscarsias)
- b) H2 Antagonist
- i) Block a 2nd type of histamine receptors:
- (1) Cimetidine (Tagamet®), famotidine (Pepcid®), nizatidine (Axid®), rantidine (Zantac®)
- ii) These agents are not antihistamines as we know them
- iii) Therapeutic Uses:
- (1) Decrease gastric secretion (ulcer patients)
- (2) Treat heartburn (esophageal reflux) – unapproved use
- (a) Preliminary studies look promising for this use
- iv) Side Effects:
- (1) Minimal
- (a) Doesn’t cause usual sedation in most patients
- (b) Occasionally, causes diarrhea, muscle pain, rash, dizziness
- (c) Also, because inhibits P450 enzymes, can delay metabolism of other drugs in liver
- (2) Very rare
- (a) Breast enlargement in some men
- (b) Mental confusion in older patients
- 10) Main differences between drugs used to stop a reaction from progressing and relieving symptoms from histamine that has already been released
- a)
-
11) Why use an antacid
- a) Therapeutic Uses:
- i) Peptic ulcer
- ii) Heartburn (may increase tone of lower esophageal sphincter)
- b) Kinds
- i) Systemic antacids
- ii) Nonsystemic antacids
- iii) Sedative or Antisecretory Agents
- iv) Increase gastric emptying
- c) Systemic Antacids (Sodium bicarbonate)
- i) Not commonly prescribed by physician because may cause systemic alkalosis & electrolyte imbalance
- ii) Side Effect: kidney must then adjust for imbalance
- (1) Note: Found in effervescent products such as Alka Seltzer® and instant Metamucil®
- (2) CO2 gas and electrolyte imbalances may stimulate more aid production
- d) Nonsystemic Antacids
- i) Mechanisms:
- (1) Form insoluble products so not absorbed
- (2) Neutralize hydrogen ion
- ii) Ex:
- (1) Aluminum compounds (Rolaids®) and calcium compounds (Tums®)
- (a) Calcium may actually stimulate more acid production later (ie.e excessive milk drinking not a good idea).
- (2) Magnesium compounds (Milk of Magnesia)
- iii) Side Effects: - not serious
- (1) Al or Ca = constipation
- (2) Mg = diarrhea
- (a) Combo of 2 types help avoid problem
- (b) Al have slower onset; Mg more quickly = good combo
- iv) Caution:
- (1) Antacids alter absorption of many drugs
- (2) Particularly important if kidney/liver disease
- e) Sedative/Antisecretory Agents: Inhibit secretion by different mechanisms
- i) H2 antagonists – inhibit gastric secretion
- (1) Ex: Cimetidine (Tagamet®)
- ii) Anticholinergic drugs (ex: Donnatal®)
- iii) Prostaglandins – misoprostol (Cystotec®)
- (1) Reduces acid, increases mucus secretion
- (2) Contraindicated in pregnancy (miscarriages has occurred)
- iv) Proton Pump Inhibitors
- (1) Short term use (4-8 weeks)
- (2) Directly diffuses into gastric epithelium ot suppress acid secretion
- f) Increase Gastric Emptying (Drugs): Seems to increase sensitivity to acetylcholine
- i) Ex: cisapride (Propulsid®), metoclopramide (Reglan®)
- ii) Relaxes pylorus & stimulates motility
- iii) Relieves heartburn & nausea caused by gaseous distention
- g) About Ulcers:
- i) Older ulcer treatments focus on antacids
- (1) Best after each meal & bedtime
- (2) Not as effective as H2 antagonists, but not as much rebound ulceration
- ii) Note: Sucralfate (Carafate®), aluminum hydroxide & sulfate sucrose
- (1) Minimal antacid effect
- (2) Adheres to ulcerated region (protect it) & decrease pepsin activity
- (3) Sucralfate is as effective as H2 antagonist at healing
- (a) Its best used before meal & before antacids because needs some acid to become active
-
12) What is a digestant, emetic, antiemetic, cathartic, antidiarrheics? When to use and when not to use.
- a) Digestants
- i) Most no longer considered effective
- (1) Includes acids & enzymes
- ii) Exception
- (1) Pancreatic enzymes are still considered useful
- b) Emetics
- i) Cause vomiting – (apomorphine, ipecac)
- ii) Therapeutic Uses – poisoning
- iii) Caution:
- (1) w/ some poisons, vomiting is contraindicated:
- (a) convulsant drug
- (b) oil based substances
- (c) corrosive substances
- c) Antiemetic: Note: vomiting reflex stimulated by GI & CNS irritation
- i) Local antiemetic
- (1) Releiaves irriation
- (a) Antacis
- (b) Carminatives (relieve gas)
- ii) Systemic antiemetics
- (1) Depress vomiting center in medulla
- (a) Phenothiazines – among more effective
- (b) Antihistamines – if cause is motion sickness
- (i) Use prior to onset of symptoms
- (c) Tetrahydrocannabinol (THC)
- (i) Active ingredient in marijuana
- (ii) Often useful if nausea due to chemotherapy
- (iii) Main antiemetic value in patiens who don’t respond to other antiemetics such as prochlorperazine (Compazine®)
- (iv) Side effects
- 1. Drowsiness
- 2. Dry mouth, tachycardia
- 3. Dizziness, inability to concentrate, disorientation
- 4. Anxiety, depression, paranoia, manic psychosis, visual hallucinations
- (d) Metoclopramide (Reglan ®) – relaxes pylorus & stimulates motility
- (i) Relieves heartburn & nausea caused by gaseous distention
- d) Cathartics (means to cleanse)
- i) Contrast w/ laxatives or purgatives
- ii) Major causes of constipation include
- (1) Lack of diet fiber
- (2) Lack of exercise
- (3) Drugs, overuse of cathartics
- (4) Lack of peristalsis (many causes)
- iii) Therapeutic Uses
- (1) Treat or avoid constipation – some significant ex:
- (a) Bedridden patients
- (b) Patients w/ hemorrhoids
- (c) Patients w/ cardiovascular disease
- (2) Surgery or diagnostic procedures
- (3) Worms infestation
- (a) Used in conjunction w/ poison for worm
- (4) Chemical poisoning
- (a) When chemical has gotten past stomach
- iv) Contraindications:
- (1) Undiagnosed abdominal pain
- (a) Appendicitis (may lead to rupture)
- (b) Inflammatory disease of GI tract (too irritating)
- (2) GI obstruction including fecal impaction
- (3) Later stages of pregnancy
- v) MOA:
- (1) Irritant (acts as stimulant to peristalsis)
- (a) Caster oil, phenolphthalein
- (2) Bulk-forming (colloids like agar & methlcellulose that attract water)
- (a) Some brand names: Metamucil®, Cologel®, Mitrolan®
- (b) Lactulose (Chronulac®) acts as an osmotic agent and as an irritant
- (c) Natural sources: fruits & vegetables
- (d) Special notes: these same drugs may be used to treat diarrhea
- (3) Saline cathartics
- (a) Ex: Milk of Magnesia & other magnesium salts
- (b) Hypertonic saline that attracts water to feces caution if renal impairment
- (c) Uses: Treat edema; Secure stool specimens for worms; Some poisonings
- (4) Lubricants & fecal moistening agents – (both act to keep feces soft)
- (a) Hemorrhoid surgery, myocardial infarctions, aneurysms, cerebrovascular disorders
- (b) Ex: mineral oil, glycerin suppositories, sodium docusate
- (c) Oils may inhibit absorption of fat soluble nutrients (take on empty stomach)
- e) Antidiarrheics
- i) Important problem: diarrhea can cause
- (1) Dehydration
- (2) Exhaustion
- (3) Electrolytes & acid-base imbalance
- ii) Note: Treatment of chronic diarrhea should be aimed at the problem
- (1) Laxative abuse
- (2) Lactose intolerance
- (3) Irritable bowel syndrome, Crohn’s disease, etc.
- iii) MOA:
- (1) Demulcents and protective
- (a) Help prevent irrigation (limited usefulness)
- (2) Absorbents – absorb gas or irritating substance
- (a) Bismuth subsalicylate, Kaopectate®, activated charcoal
- (3) Astringents – precipitate protein & cover surface of membrane
- (a) Prevents further irritation, shrinks tissue
- (4) Antiinfectives – if caused by microorganisms
- (a) Note: do not inhibit peristalsis if microorganism present
- (5) Sedatives & antispasmodics – opium preparation & antimuscarinic
- (a) Ex: Imodium®, Lomotil®, paregoric are combinations of a narcotic and an antimuscarininc drug
- (6) Lactobacillus – normalizes intestinal flora
- (a) Especially good if diarrhea follows antibiotic therapy
- f) Carminatives/antiflatulents
- i) + motility to help expel gas
- ii) Simethicone is an antifoaming agent
- iii) Charcoal capsules for intestinal gas
- (1) As much as one gram before & after meals
- (2) Caution: absorbs oral medications
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