McKenna's Pharmacology for Nursing, 2e

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P A R T 5  Drugs acting on the autonomic nervous system

CHAPTER SUMMARY ■■ 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. 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. 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. 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 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,

■■ 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 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. 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: