CHAPTER TWELVE

Centrally Acting Muscle Relaxants: should be used short-term

• cyclobenzaprine

• diazepam

• tizanidine

adverse effects: hepatotoxicity, generalized CNS depression, physical dependence (→ abstinence syndrome)

Drugs for Spasticity: can treat MS and cerebral palsy

• baclofen (acts in CNS) mimics the action of GABA → suppresses hyperactive reflexes

  • tx: MS, CP, spinal cord injury, not stroke

  • adverse effects: GI symptoms

  • considerations: no antidote; gradual withdrawal over 1-2 wks. (abrupt → rhabdomyolysis)

• diazepam (acts in CNS) mimics the action of GABA

  • tx: alcohol withdrawal & anxiety

• dantrolene (acts directly on skeletal muscle)

  • tx: malignant hyperthermia, MS, etc.

  • adverse effects: hepatotoxicity

HERB ALERT (kava)

• uses: anxiety, stress, restlessness, promotes sleep, muscle relaxation

• adverse effects: eye disturbances, depressant effects

• drug interactions: CNS depressants, MAOIs

HERB ALERT (valerian)

• uses: anxiety, stress, insomnia

• drug interactions: CNS depressants, MAOIs, phenytoin, alcohol

• contraindications: CV disease

CHAPTER FIFTEEN

Parkinson’s disease: imbalance btwn acetylcholine (high) & dopamine (low)

Mild PD tx:

MAO-B inhibitors

• selegiline

• rasagiline

Severe PD tx:

• levodopa

  • MOA: converted into dopamine after crossing BBB; broken down by pyridoxine (vit B6)

  • food delays absorption, esp. high protein foods

  • given w/carbidopa (prevents breakdown & reduced N/V)

  • contraindicated w/ angle-closure glaucoma & malignant melanoma

  • adverse effects: dark urine/sweat, activates malignant melanoma

dopamine agonists: first-line drugs; does not compete with proteins; activates dopamine receptor

• pramipexole

  • takes several weeks to develop maximum effects

• ropinirole

  • tx PD and restless legs syndrome

• rotigotine

• apomorphine

  • subcutaneous route

  • “last resort”

• bromocriptine

COMT inhibitors: inhibit dopamine breakdown in periphery

• entacapone: selective & reversible COMT inhibitor

  • prolongs levadopa effects

• tolcapone

  • reduces “wearing off” effect

  • d/c’d if no results w/n 3 weeks

MAO-B inhibitors:

• selegiline

• rasagiline

dopamine modulators:

• amantadine

  • response diminished w/n 3 months

centrally acting anticholinergics:

• benztropine

  • no bradykinesia effects

CHAPTER 51

diarrhea

- acute: up to 2 weeks; caused by bacteria, virus, etc.

- chronic: more than 3-4 weeks; caused by tumors, DM, hyperthyroidism, Addison’s disease, etc.

antidiarrheals: adsorbents (used in milder cases) anticholinergics & opiates (used in more severe cases)

absorbents:

- MOA: coats walls of GI tracts, bind to causative agent → eliminated through stool

- adverse effects (similar to aspirin): increased bleeding time, constipation/dark stools, confusion, tinnitus, metallic taste, blue tongue

• bismuth subsalicylate

  • do NOT give to children or teens with chickenpox/influenza (→ Reye’s syndrome)

anticholinergics: decreases intestinal muscle tone & peristalsis of GI tract, reduces gastric secretions, drying effect

- adverse effects: urinary retention, dry mouth, etc.

- do NOT give to pt with narrow-angle glaucoma, GI obstruction, myasthenia gravis, toxic megacolon, etc.

opiates:

- adverse effects: respiratory depression, hypotension, N/V/C, flushing

• loperamide:

probiotics: replenishes healthy bacteria

• Lactobacillus acidophilus: suppress bad bacteria and supplies good bacteria

laxatives: used to ease/stimulate defecation

- contraindications: bowel obstruction, N/V, abdominal pain

bulk forming:

• psyllium

emollients:

• docusate

hyperosmotics: increases fecal h20 content

• polyethylene

• lactulose

saline: do NOT use with renal failure

• magnesium hydroxide

• magnesium salts

stimulants: induce intestinal peristalsis; most likely to → dependence

• senna

• bisacodyl

peripherally acting

CHAPTER 52

vomiting center (VC)
chemoreceptor trigger zone (CTZ)

anticholinergics (Ach blockers):

• scopolamine: transdermal patch (behind ear) switched every 3 days

antihistamines (H1 receptor blockers): inhibit Ach by binding to H1

- very drying → dehydration, hypotension

• diphenhydramine

• dimenhydrinate

• meclizine

antidopaminergics (dopamine antagonists): block dopamine receptors in CTZ

• promethazine

• prochlorperazine

neurokinin receptor antagonists: inhibit substance P

prokinetic drugs: block dopamine receptors in CTZ, also stimulate peristalsis in GI

• metoclopramide

serotonin blockers: block serotonin receptors in GI tract

- side effects: prolonged QT

tetrahydrocannabinoids: inhibitory effect on reticular formation, thalamus, and cerebral cortex

- stimulates appetite

• dronabinol

  • used for N/V associated with chemo

glucocorticoids:

- contraindicated with active fungal infxn, systemic infxn, or cerebral malaria

• dexamethasone

• methylprednisone

benzos:

• lorazepam: used in combo regimens to suppress CINV (not used alone)

misc. drugs

• phosphorated carbohydrate solution (Emetrol): mint-flavored oral solution

herbs

• ginger: can tx N/V associated with chemo, pregnancy, etc.

CHAPTER 36

***OTC cough & cold meds are not to be given to peds < 2 years old due to risk for oversedation, seizures, tachycardia, and death (US FDA)

decongestants: rebound congestion

- oral: no rebound congestion, all adrenergic

- topical: more potent and prompter onset

- contraindications: narrow-angle glaucoma, uncontrolled CVD (HTN), inability to close eyes, diabetes, hyperthyroidism, CVA hx, long-standing asthma, BPH

- interactions: sympathomimetics, MAOIs, caffeine

• adrenergics: constrict small arterioles of upper resp tract to allow for better drainage

  • ephedrine

  • oxymetazoline (only use for 3-4 days max)

• anticholinergics: drying out effect

  • ipratropium

• corticosteroids: decrease inflammation by turning off inflammatory cells

  • fluticasone

  • flunisolide

  • triamcinolone

antitussives: only used for nonproductive cough

- contraindications: respiratory depression, increased ICP, seizures

• opioid antitussives:

  • codeine (may be w/ guaifenesin): suppresses cough center

  • hydrocodone

• nonopioid antitussives:

  • dextromethorphan: same MOA as opioids but no CNS depression

  • benzonatate: decrease reflex stim in medulla, numbs cough receptors

mucolytics: act directly on mucus to make it less viscous

• acetylcysteine: has sulfuric smell, tx acetaminophen toxicity

expectorants: aid in mucus removal, may be used for productive/non-productive coughs

- MOA: decrease reflex stimulation

• guaifenesin: increases hydration of resp tract → maintains ciliary clearance and decreases mucus viscosity

herbs:

• echinacea

CHAPTER 37

URT diseases: cold, rhinitis, hay fever

LRT diseases: asthma, COPD

asthma

1. intrinsic (no allergy hx)

2. extrinsic (due to known allergen)

3. exercise induced

4. drug induced

• bronchodilators

  • beta-adrenergic agonists:

    • nonselective adrenergics: + beta, beta1, beta2 receptors; tx acute asthma/COPD attacks

      • epinephrine

    • nonselective beta-adrenergics: + beta, beta2 receptors

      • metaproterenol

    • selective beta2 drugs: + beta2 receptors

      • albuterol: (SABA)

      • salmeterol: (LABA)

  • anticholinergics: block Ach receptors to prevent bronchoconstriction → airway relaxation & dilation to prevent COPD bronchospasms

    • ipratropium

    • tiotropium

    • aclidinium

  • xanthine derivatives: decrease cAMT levels (inhibits phosphodiesterase)→ bronchodilation; cigarette smoking enhances xanthine metabolism

    • theophylline: very small therapeutic range

• nonbronchodilating resp drugs

  • leukotriene receptor antagonists (LTRAs): prevent bronchoconstriction

    • montelukast: approved for pts >1 year (black box warning)

    • zafirlukast

    • zileuton

  • corticosteroids: take AFTER bronchodilator; tx chronic asthma; contraindicated with systemic fungal infections; rinse mouth after to prevent thrush

    • fluticasone propionate

    • methylprednisone

  • phosphodiesterase-4 inhibitors: prevents coughing & excess mucus from worsening

    • roflumilast

  • monoclonal antibody antiasthmatics: decreases immune response

    • omalizumab

    • mepolizumab

    • reslizumab