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P A R T 5
Drugs acting on the autonomic nervous system
CHAPTER SUMMARY
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Cholinergic drugs are chemicals that act at the same
site as the neurotransmitter acetylcholine (ACh),
stimulating the parasympathetic nerves, some nerves
in the brain and the neuromuscular junction.
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Direct-acting cholinergic drugs react with the ACh
receptor sites to cause cholinergic stimulation.
■■
Use of direct-acting cholinergic drugs is limited by
the systemic effects of the drug. They are used to
induce miosis and to treat glaucoma; one agent is
available to treat neurogenic bladder and bladder
add to his difficulty swallowing; nausea and vomiting,
which could make it difficult to maintain nutrition; and
cramps, diarrhoea and involuntary defaecation related
to the increase in GI secretions and activity, which could
make toileting difficult and add to Mrs. J.’s home care
burden. Cardiovascular effects can include bradycardia,
heart block and hypotension, which could lead to
dizziness and weakness and further complicate safety
issues. Urinary tract effects can include a sense of urgency
related to stimulation of the bladder muscles and sphincter
relaxation, which could lead to incontinence as the person
becomes less responsive to normal reflexes. Miosis and
blurred vision, headaches, dizziness and drowsiness can
occur, further complicating safety issues. The benefits of
slowing the progression of the disease often need to be
weighed against all of the potential adverse effects that can
complicate care and safety.
CARE GUIDE FOR A.J.: INDIRECT-ACTING
CHOLINERGIC AGONISTS
Assessment: History and examination
Assess for contraindications or cautions: known allergies
to any of the components of this drug, arrhythmias,
coronary artery disease, hypotension, urogenital or
GI obstruction, peptic ulcer, recent GI or genitourinary
surgery, and regular use of NSAIDs, cholinergic drugs or
theophylline.
Focus the physical examination on the following:
CNS: orientation, affect, reflexes, memory response, ability
to carry out simple commands, vision
CV: blood pressure, pulse, peripheral perfusion, ECG
GI: abdominal exam
GU: urinary output, bladder tone
Respiratory: respirations, adventitious sounds
Skin: colour, temperature, texture
Implementation
Ensure safe and appropriate administration of the drug;
monitor the ability to swallow and the appropriateness
of dosage form.
Provide comfort and safety measures (e.g. physical
assistance, raising side rails on the bed); temperature
control; pain relief; small, frequent meals.
Monitor cardiac status and urine output throughout drug
therapy.
Provide support and reassurance to deal with side effects,
discomfort and GI effects.
Provide the individual and the family with teaching
regarding drug name, dosage, side effects, precautions
and warning signs of serious adverse effects to report.
Evaluation
Evaluate drug effects: slowing of progression of dementia.
Monitor for adverse effects: CV effects—bradycardia,
heart block, hypotension; urinary problems; GI effects;
respiratory problems.
Monitor for drug–drug interactions.
Evaluate the effectiveness of teaching program and
comfort and safety measures.
INDIVIDUAL/FAMILY TEACHING FOR A.J.
• The drug that was ordered for you is called rivastigmine.
It is called a cholinergic agonist or a parasympathetic drug
because it mimics the effects of the parasympathetic
nervous system. Cholinergic drugs get this name because
they act at certain nerve–nerve and nerve–muscle
junctions in the body that are called cholinergic sites.
They use a chemical called acetylcholine (ACh) to carry
out their functions. The nerves in your brain that are
affected by Alzheimer’s disease use ACh to help you
to remember things and make connections between
memories.
• Some of the following adverse effects may occur.
•
Nausea, vomiting, diarrhoea
: It is wise to be near
bathroom facilities after taking your drug. If these
symptoms become too severe, consult with your
healthcare provider.
•
Flushing, sweating
: Staying in a cool environment and
wearing lightweight clothing may help.
•
Increased salivation
: This may increase your difficulty in
swallowing.
•
Urgency to void
: Maintaining access to a bathroom may
relieve some of this discomfort.
•
Headache
: Aspirin or another headache medication
(if not contraindicated in your particular case) will help
to alleviate this pain.
•
Changes in vision, dizziness
: These might lead to falls or
more confusion.
• Report any of the following to your healthcare provider:
very slow pulse, light-headedness, fainting, excessive
salivation, abdominal cramping or pain, weakness or
confusion, blurring of vision, further signs of dementia.
• Tell any doctor, nurse or other healthcare provider
involved in your care that you are taking this drug.
