Nursing School Notes

  • Act in limbic system & reticular activating system (RAS) (blocking brain’s response to incoming stimuli)
  • make GABA more effective (opens Cl- channels, hyperpolarizing cells - becomes more difficult to depolarize, reducing excitability)
  • most widely used anxiolytic drugs – safer, more effective, less potential for addiction & does not cause much sedation
    - Lower doses cause anxiolytic effects – reduction in anxiety w/o causing much sedation
    - Higher doses cause sedation and hypnosis
  • Other uses:
    - Anticonvulsants
    - Muscle relaxants

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Indications:
  • Relieve S&S of anxiety disorders 
  • Alcohol withdrawal 
  • Hyperexcitability / agitation 
  • Pre-op relief of anxiety & tension (lower dose)
  • Balanced anesthesia 
  • Seizures (anticonvulsant effect) 
  • Conscious sedation (Producing IV anesthetic)
  • Muscle spasms (Producing skeletal muscle relaxation)
  • Anxiety, insomnia


Contraindications:
  • Psychosis 
  • Acute narrow angle glaucoma (May ↑ IOP) 
  • Shock 
  • Coma 
  • Acute alcohol intoxication
  • pregnancy & lactation
    - fetus can develop dependency in utero & experience withdrawal Sx


Caution:
  • 15% - 20% of African Americans genetically predisposed to delayed metabolism of benzodiazepines (leading to eventual buildup &↑ AE)
  • Older Adults – ↑ CNS effects 
  • Effects on fetus and neonate: 
    - Cleft lip and/or palate
    - Cardiac defects
Adverse Reactions:
  • Sedation, Drowsiness, Lethargy 
  • Depression, Confusion
  • Blurred Vision 
  • Dry Mouth
  • Hypotension
  • urinary retention
  • N/V, Constipation
  • loss of libido 
Interactions:
  • ↑ CNS depression when taken with alcohol 
  • ↑ in effect when taken w/ cimetidine, oral contraceptives, or disulfiram (Antabuse) 
  • ↓ in effect if given with theophylline or ranitidine (Zantac) 


Kinetics:
  • Well absorbed from GI tract; Lipid soluble and distributes well throughout the body 
  • Peak levels achieved in 30 minutes to 2 hours 
  • Metabolized in the liver; Excretion is primarily in the urine

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Drugs:

1. Diazepam (Valium) & Clorazepate (Tranxene) - fast onset (30min)


2. Oxazepam (Serax) - slow onset (~ 2hrs)


3. Lorazepam (Ativan), Alprazolam (Xanax), Clonazepam (Klonopin) - intermediate onset


Drugs by Use:

  • Anxiety Disorders:
    - alprazolam (Xanax), chlordiazepoxide (Librium), clorazepate (Tranxene), diazepam (Valium), lorazepam (Ativan), midazolam 

  • Seizure Disorders
    - clonazepam (Klonopin), clorazepate (Tranxene), and diazepam (Valium)

  • Insomnia
    - estazolam, flurazepam, quazepam (Doral), temazepam (Restoril), triazolam (Halcion)

  • Anesthesia
    - midazolam, lorazepam (Ativan), and diazepam (Valium) 

  • Muscle Relaxation
    - diazepam (Valium)

  • Alcohol Withdrawal
    - chlordiazepoxide (Librium) 

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Nursing Mgmt
  • Avoid alcohol & other CNS depressants during therapy (to avoid severe drowsiness, respiratory depression, apnea)
  • Do not drive or engage in other potentially hazardous activities or those requiring mental precision until reaction to drug is known. 
  • Tell physician if you become or intend to become pregnant during therapy; drug may need to be discontinued. 
  • Take drug as prescribed; do not change dose or dose intervals. 
  • Check with physician before taking any OTC drugs. 
  • Do not breast feed while taking this drug without consulting physician. 
  • Psychic & physical dependence may occur in pt on LT high dosage therapy, in pt w/ Hx alcohol or drug addiction, or in pt who self-medicates
  • Abrupt stop may lead to withdrawal syndrome (nausea, headache, vertigo, malaise and nightmares)
  •  dec dose in elderly (dec liver/kideny function)
  • before using these drugs try: exercise, good sleep hygiene, relaxation techniques
  • IV - do not mix with other agents; slowly - connection closest to the vein – rate (5mg/minute)– hypotension, bradycardia, cardiac arrest. BR x 3 hours post administration 
  • No intra-arterial administration – IV only w/ caution 
  • No driving or operation of heavy mechanical equipment
  • Antidote:
    - Flumazenil (Romazicon) a benzodiazepine receptor antagonist antidote for overdose; indicated to reverse sedative effects of benzos 

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Benzodiazapines

  • Block only the muscarinic receptors in the PNS and cholinergic receptors in the SNS 
  • Act by competing with acetylcholine for the muscarinic acetylcholine receptor sites 
  • Do not block the nicotinic receptors 
  • Actions:
      - ↑ HR
      - ↓ GI activity
      - ↓ urinary bladder tone & function
      - dilate pupils

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 Indications:
  • decrease secretions before anesthesia
  • treat parkinsonism (by blocking the stimulating effects of acetylcholine)
  • restore cardiac rate & BP s/p vagal stimulation during surgery
  • relieve brady s/p hyperactive carotid sinus reflex
  • relieve pylorospasm & hyperactive bowel
  • prevent S&S of motion sickness & vomiting
  • relax biliary and ureteral colic
  • relax bladder detrusor muscles & tighten sphincters
  • help to control crying or laughing episodes in pt w/ brain injuries
  • relax uterine hypertonicity
  • help in the management of peptic ulcer
  • control rhinorrhea associated with hay fever
  • antidote for cholinergic drugs and for poisoning by certain mushrooms
  • ophthalmic agent to cause mydriasis or cycloplegia in acute inflammatory conditions 


Contraindications:
  • glaucoma
  • stenosing peptic ulcer
  • intestinal atony, paralytic ileus, GI obstruction
  • severe ulcerative colitis
  • toxic megacolon
  • prostatic hypertrophy, bladder obstruction
  • cardiac arrhythmias, tachycardia, myocardial ischemia
  • impaired liver or kidney function 
  • myasthenia gravis (Low doses of atropine sometimes used in MG to block unwanted GI & CV effects of the cholinergic drugs used to treat it)


Caution:
  • pregnancy & lactation
  • HTN
  • spasticity, brain damage
Adverse Reactions:
  • Weakness, dizziness, insomnia, mental confusion, excitement
  • blurred vision, pupil dilation (w/ photophobia, cycloplegia, ↑ IOP)
  • Dry mouth, altered taste perception
  • possible tachycardia & palpitations
  • Urinary hesitancy and retention
  • nausea, heartburn, constipation, bloated feelings, paralytic ileus
  • ↓ sweating & an ↑ predisposition to heat prostration 


Interactions:
  • ↑ effects w/ antihistamines, antiparkinsonism drugs, MAOIs, tricyclic antidepressants (all have anticholinergic activity)

Kinetics:
  • Well absorbed & Widely distributed throughout the body
  • excreted in the urine
  • Crosses blood brain barrier

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Drugs:

1. Atropine

Actions:
  • Depresses salivation and bronchial secretions
  • Dilates the bronchi
  • Inhibits vagal responses in the heart
  • Relaxes the GI & GU tracts
  • Inhibits GI secretions
  • Causes mydriasis 
  • Causes cycloplegia (paralysis ciliary muscles)

Indications:
  • ↓ secretions (before surgery)
  • bradycardia
  • pylorospasm, ureteral colic, relaxing of bladder
  • emotional lability with head injuries
  • antidote for cholinergic drugs
  • pupil dilation 
  • Parkinsonism 

AE:
  • Blurred vision, Mydriasis (pupil dilation), Cycloplegia (↓ accommodation reflex), Photophobia 
  • Palpitations, bradycardia 
  • Dry mouth, altered taste perception 
  • Urinary hesitancy & retention 
  • ↓ sweating (predisposition to heat prostration)



2. Dicyclomine
- relaxes GI tract; Tx hyperactive or irritable bowel


3. Glycopyrrolate (Robinul)
- adjunct therapy in Tx ulcers


4. Propantheline (Pro-Banthine)
- adjunct in Tx ulcers


5. Scopolamine (Transderm Scop)
- dec N/V associated w/ motion sickness


6. Tiotropium (Spiriva)
 -Tx bronchospasm/COPD

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Nursing Mgmt
  • Assess & monitor:
  •     CV & Respiratory 
  •     CNS (LOC, orientation, reflexes) 
  •     GI (Constipation)
  •     GU (Urinary retention)
  •     Renal 
  • Monitor for dry mouth & difficulty swallowing
  • elderly & children more susceptible to adverse effect - reduce dose (constipation, urinary retention, heat intolerance, and confusion)
  • BUT don't use Dicyclomine w/ kids
  • Teaching:
   - void before taking med
   - dry lots of fluids
   - avoid hot temperatures
   - safety precautions for dizziness/blurred vision

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Anticholinergics

  • React with acetylcholinesterase preventing Ach from breaking down – results in ↑ Ach 
  • May bind reversibly or irreversibly 
  • Irreversible:
     - Not used therapeutically
     - Being developed to as nerve gas to be used as weapons
     - War setting – antidote readily available 

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Indications:
  • Myasthenia gravis (autoimmune disease of progressive muscle weakness / lack of muscle control)
  • Alzheimer's (there is a progressive loss of ACh-producing neurons & their target neurons)

Contraindications:
  • Allergy 
  • Bradycardia 
  • Intestinal or urinary tract obstruction 
  • Lactation

 Caution:
  • Any condition that could be exacerbated by cholinergic stimulation 
  • Asthma, CAD, PUD, arrhythmias, epilepsy, or parkinsonism

 Adverse Reactions:
  • Bradycardia, Hypotension
  • Bronchoconstriction  
  • ↑ bladder tone 
  • ↑ GI secretions & activity 
  • Relaxation of GI & GU sphincters 
  • Pupil constriction (miosis)

Interactions:
  • ↑ risk GI bleed if used w/ NSAIDs 
  • ↓ anticholinesterase effects if taken w/ any cholinergic drugs because these work in opposition to each other
  • ↑ theophylline levels w/ tacrine

Kinetics:
  • Well absorbed and distributed throughout the body 
  • Metabolized in the liver and excreted in the urine

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Drugs to Treat Myesthenia gravis:

1. Neostigmine (Prostigmine) - works at neuromuscular junction


2. Pyridostigmine (Regonol, Mestinon) - longer duration than neostigmine


3. Ambenonium (Mytelase) - only PO; cannot be used if patient is unable to swallow


4. Edrophonium (Tensilon, Enlon) - diagnostic agent for myasthenia gravis

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Drugs to Treat Alzheimer's:

1. Tacrine (Cognex) - 1st drug out there to treat Alzheimer's


2. Galantamine (Reminyl) - used to stop Alzheimer's progression


3. Rivastigmine (Exelon) - available in solution for swallowing ease


4. Donepezil (Atricept) - once-a-day dosing!

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Nursing Mgmt
  • if IV administer slowly 
  • Atropine sulfate on-hand in case of crisis (antidote) 
  • Observe for excessive salivation, diarrhea, emesis, excessive urination 
  • should be taken w/ meals 
  • Prevent injury 
  • Teaching

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Nerve Gas – Irreversible Indirect Cholinergic Agonist:

  • Irreversible acetylcholinesterase inhibitor 
  • Leads to toxic accumulation of ACh at cholinergic receptor sites


 Antidotes:
Pralidoxime (Protopam Chloride); works in PNS 
  • IM or IV
  • frees up acetylcholinesterase to start breaking down ACh
  • on-hand for MG receiving an IDCA
  • antidote for irreversible acetylcholinesterase-inhibiting drugs, or nerve gas
  • Organophosphate pesticide poisoning

Atropine; works in CNS
  • Block cholinergic activity & active Ach in CNS
  • Activate Acetylcholinesterase to breakdown Ach

Adverse Effects
  • Blurred vision, dizziness, diplopia, headache, hyperventilation
  • Can cause parasympathetic crisis and muscle paralysis






Indirect-Acting Cholinergic Agnoists

  • Chemicals that act at the same site as the neurotransmitter acetylcholine (ACh)
  • Similar response as parasympathetic system activation - Effects are widespread
  • These drugs usually stimulate muscarinic receptors in PNS 
  • used as systemic agents used to:
        - ↑ bladder tone, urinary excretion, & GI secretions
        - also used as ophthalmic agents to induce miosis to relieve ↑ IOP of glaucoma via pupil constriction (not systemic when used ophthalmically)
        - ↓ HR, ↓ myocardial contractility, bronchoconstriction & ↑ bronchial mucous secretion

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Contraindications:
  • Any condition that would be exacerbated by parasympathetic effects—bradycardia, hypotension, CAD
  • PUD, intestinal obstruction or recent GI surgery  
  • Asthma 
  • Bladder obstruction 
  • Epilepsy & parkinsonism

 Caution:
  • pregnancy / lactation

Adverse Reactions:
  • N/V, diarrhea, cramps, involuntary defecation 
  • Bradycardia, heart block, hypotension 
  • Urinary urgency 
  • Flushing, ↑ sweating & salivation, swallowing difficulty

Interactions:
  • ↑ risk of cholinergic effects if these drugs are combined or given with acetylcholinesterase inhibitors 

Kinetics:
  • Well absorbed and have relatively short half-life (1-6 hr) 
  • Metabolized; excretion of these drugs is not known

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Drugs:

1. Bethanechol (Duvoid, Urecholine)
   - urinary retention
   - urogenic bladder
   - esophageal reflux in infants/kids

Mgmt:
  • Produces muscarinic effects primarily on GI tract & urinary bladder
    •     ↑ tone & peristaltic activity of esophagus, stomach, and intestine
    •     contracts detrusor muscle of urinary bladder, usually enough to initiate micturition.
    •     cant help if obstructed 
  • must monitor for effectiveness - i.e are they having problem still w/ urinary retention? (relief should be quick)
  • if not working, could be structural problem (BUN & Cr will go way up)



2. Carbachol (Miostat)
- induces miosis to ↓ IOP


3. Cevimiline (Exovac)
- Tx dry mouth


 4. Pilocarpine (Salagen)
- Tx dry mouth (xerostomia) s/p radiation therapy of head & neck tumor 
- glaucoma (constricts pupil & ↓ IOP)

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Nursing Mgmt
Baseline Assessment: 
  • Cardiovascular  - HR, BP CAD 
  • GI - Bleeding, ulcer disease, obstruction, dehydration 
  • Respiratory assessment  - Asthma 
  • GU - Recent bladder surgery or obstruction 
  • CNS - Parkinson’s and/or epilepsy



Direct-Acting Cholinergic Agonists

  • Do not usually block beta-2 receptor sites, including sympathetic bronchodilation 
  • Preferred for patients who smoke or have asthma, obstructive pulmonary disease, or seasonal /  allergic rhinitis


Indications
  • HTN
  • angina
  • some cardiac arrhythmias
  • open-angle glaucoma


Contraindications
  • brady, heart block
  • shock, CHF, hypotension


Cautions
  • COPD
  • DM, thyroid disease


Adverse Effects
  • CNS: Fatigue, dizziness, sleep disturbances
  • CV: Bradycardia, heart block, CHF, hypotension
  • Resp: Sx in resp tract (range from rhinitis to bronchospasm)
  • GI: N/V, diarrhea
  • ↓ libido and impotence


Kinetics
  • absorbed from GI
  • metabolized in liver and are excreted in the urine

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Drugs
Atenolol (Tenormin)
  • Tx MI, angina 
  • most used drug in its class for HTN


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 Drug Interactions
  • ↓ HTN effects w/ clonidine, NSAIDs, rifampin 
  • ↑ toxicity IV lidocaine if given w/ these drugs
  • ↑ risk orthostatic hypotension w/ prazosin


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 Nursing Mgmt for All A&B Agonists
  • Check apical pulse before PO admin, esp. in pt receiving digitalis (both drugs slow AV conduction)
    •       If < 60 bpm, withhold dose & consult physician
  • Monitor apical pulse, BP, respirations, & peripheral circulation throughout dosage adjustment period. Consult physician for acceptable parameters. 
  • Sudden d/c of drug can exacerbate HTN, angina, & precipitate tachycardia or MI in pt w/ CAD, & thyroid storm in pt w/ hyperthyroidism – due to being hypersensitive to catecholamines





Beta-1 Selective Blockers

  • blocks Alpha-1 receptors at the postsynaptic sites (vs. presynaptic sites) – so they blocks effects of both NE & E
  • leads to ↓ vascular tone & vasodilation leads to ↓ BP (w/o the reflex tachy that accompanies a BP drop)
  • also blocks smooth muscle receptors in the prostate, urethra, urinary bladder neck which ↑ urine flow
  • most end in -zosin/-osin


Indications
  • BPH ( blocks smooth muscle in prostate/urinary tract to ↑ urine flow) 
  • HTN (↓ vascular tone & vasodilates)


Contraindications
  • lactation


Cautions
  • CHF
  • renal failure
  • pregnancy


Adverse Effects
  • CNS: dizziness, weakness, fatigue
  • CV: arrhythmia, hypotension, edema, CHF, angina
  • GI: N/V, abd pain, diarrhea
  • (vasodilation may cause flushing, reddened eyes, congestion, priapism/sexual dysfunction)


Kinetics
  • well absorbed after oral admin
  • undergo extensive hepatic metabolism and are excreted in the urine

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Drugs
1. Doxazosin (Cardura)
  • Tx HTN 
  • Tx BPH

Nursing Considerations for Doxazosin
  • by selective competitive inhibition of alpha 1-adrenoreceptors,  produces vasodilation in both resistance (arterioles) and capacitance (veins) vessels – results in both ↓ peripheral vascular resistance & ↓ BP
  • Monitor BP w/ pt lying down & standing – teach slow change of position
  • Monitor BP 2–6 h after initial dose or any ↑ dose. (this is when postural hypotension is most likely to occur)
    •        doses > 4mg ↑ risk postural hypotension
  • Do not drive or engage in other potentially hazardous activities for 12–24 h after first dose or an ↑ dosage or when med is restarted after an interruption in dosage. 
  • Report to the physician episodes of dizziness or palpitations. These will require a dosage adjustment.
  • Do not breast feed while taking this drug.

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2. Terazosin (Hytrin)
  • Tx HTN
  • Tx BPH

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3. Prazosin (Minipress)
  • Tx HTN (usually adjunct w/ another med)

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4. Tamsulosin (Flomax)
  • only for BPH

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5. Alfuzosin (Uroxatral)
  • only for BPH

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Drug Interactions
  • ↑ hypotensive effects w/ other vasodilators or antihypertensives (nitrates, Ca blockers, ACE-I)

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Nursing Mgmt for All A&B Agonists
  • When treating BPH, must first rule out prostate cancer so the drug can't mask cancer Sx
  • Cardura & Terazosin can be used to treat BPH – must educate pt about antihypertensive AE
  • check labs per usual (esp kidney function)
  • baseline cardiac assessment
  • ask pt about UO & urine flow (force of stream? full emptying? nocturia? frequency?)
    •        monitor I&O if hospitalized


Alpha-1 Selective Blockers

  • competitively block beta receptors in SNS
  • its therapeutic effects caused by beta-block in heart & juxtaglomerular apparatus 
    •        (-) inotrope, (-) chronotrope, (-) dromotope 
    •        this leads to ↓ arrhythmia, ↓ cardiac workload, ↓ O2 consumption
    •        & dec BP b/c juxtaglomerular cells not stimulated to secrete renin
  • drugs ending in -olol

Indications
  • Tx cardiac conditions – HTN, angina, migraine headaches, preventing re-infarction after MI
  • off label: anxiety/stage fright


Contraindications
  • brady, heart block, shock, CHF
  • COPD/asthma (blocks dilation)


Cautions
  • diabetes (blocks normal S&S of hyper-/hypoglycemia)
  • thyrotoxicosis (b/c blocking effects on thyroid gland)
  • hepatic dysfunction


Adverse Effects
  • brady, heart block, hypotension, arrhythmia, HF
  • bronchospasm, cough
  • fatigue, dizziness
  • sleep disturbance, depression
  • N/V, diarrhea
  • ↓ labido, dysuria
  • ↓ exercise tolerance / can no longer "get-up-and-go"


Kinetics
  • Well absorbed from GI tract
  • Metabolized in the liver


Drugs
1. Propranolol (Inderal)
  • Patient teaching required:
    •       teach pt to take pulse / take pulse before taking med
    •       teach pt it blocks S&S hypoglycemia
    •       teach about compliance &
    •       teach that abrupt d/c can lead to withdrawal syndrome (tremors, sweating, headache, malaise, palpitation, rebound HTN, MI, life-threatening arrhythmia)
    •       teach about postural hypotension 



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2. Sotalol (Betapace)
  • indicated for life-threatening arrhythmia & maintenance of sinus rhythm w/ AF or a-fib pt

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Drug Interactions
  • ↓ effectiveness w/ NSAIDs
  • blood glucose changes w/ diabetic meds & insulin
  • HTN may occur if given w/ clonidine

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Nursing Mgmt for Nonselective Beta Blockers
  • if used LT, do not stop abruptly! (receptors become hypersensitive to catecholamines) – can cause rapid inc BP →  MI / stroke
    •        should taper over 2wks
  • labs: liver/kidney function, thyroid function, blood glucose




Nonselective Beta Blockers

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