Cholinergics/
Anticholinergics
Anticholinergics
For which indications would you use benztropine?
Parkinson's and tardive dyskinesia (drug-induced extrapyramidal reactions)
*decreases muscle rigidity and muscle tremors
Are these the side effects for cholinergic or anticholinergic drugs?
*increased respiratory secretions *abdominal cramping *bronchospasms *dysrhythmias *hypotension
*N/V/D *bradycardia *increased sweating *increased frequency and urgency of voiding patterns
Cholinergic
Wet as the ocean! Cholinergics help PRODUCE fluid/secretions
What are drug considerations for older patients (65+)?
Absorption: gastric pH less acidic, gastric emptying slowed, movement through GI tract slowed due to decreased muscle tone and activity, blood flow to GI tract reduced, decreased absorptive surface area of GI tract
Distribution: lower total body water percentage; increased fat content; decreased production of proteins by the liver resulting in decreased protein binding of drugs (and increased circulation of free drugs)
Metabolism: aging liver produces fewer microsomal enzymes, affecting drug metabolism
Excretion: decreased GFR; drugs are cleared less effectively
Considerations: higher use of medications, polypharmacy, noncompliance, increased incidence of chronic illness, sensory and motor deficits, decline in organ function, more likely to experience drug adverse effects and toxicity
What are drug considerations for pediatrics?
Absorption: Gastric pH less acidic until 1-2years; gastric emptying slowed; IM absorption faster and irregular
Distribution: greater total body water means lower fat content; decreased level of protein binding; immature blood/brain barrier
Metabolism: liver & kidneys immature/still developing - can't metabolize or excrete medications as well as adults
Excretion: kidney immaturity affects GFR - reduced excretion of drugs
What is pharmacodynamics?
the study of how the DRUG affects the BODY
Mechanism of action, therapeutic effects
What is used for treatment of mild to moderate Alzheimer's disease?
Donepezil
*increases acetylcholine in brain; helps to increase or maintain memory and learning capabilities
*for management of symptoms, NOT A CURE
What are the signs of cholinergic poisoning?
SLUDGE
Salivation Lacrimation Urinary incontinence Diarrhea Gastrointestinal cramps Emesis
Which medication is an adjunctive agent to antiparkinsonian medications, increasing dopamine by inhibiting MAO-B?
Selegiline
*does not cause hypertensive crisis like other MAOIs
*less likely to cause "cheese effect" when interacting with tyramine, formed in ripe cheese
How do you dose pediatric patients?
Milligrams per kilograms (NOT pounds)
also always measure height in CM not inches
What is pharmacokinetics?
the study of what the BODY does to the DRUG
Absorption: when will it start working? bioavailability - the extent of drug absorption; first pass effect
Distribution: transport of a drug by the bloodstream to site of action (albumin is most common blood protein and carries the majority )
Metabolism: usually kidney or liver
Excretion: elimination of drugs from the body
Which medication is a transdermal patch worn behind the ear to prevent motion sickness or postoperative nausea?
Scopolamine
Which drug is the reversal for cholinergic poisoning?
Atropine
("can't pee with atropine!"
Which medication treats muscle tremors and muscle rigidity in Parkinson patients?
Benztropine
*anticholinergic effects
*take at night if possible
What are patient teaching points for antiepileptic drugs?
*Take at the same time daily
*Take with meals
*Do not crush, chew, open extended-release forms
*Driving may be impaired
*Therapy is not a cure
*Medical-alert tag should be worn
What are peak level and trough level?
Peak: highest amount of drug found in blood level
Trough: lowest amount of drug found in blood level - draw no more than 30 min before next dose administration
If your patient has reflex neurogenic bladder (due to a spinal cord injury), which medication is likely to be prescribed?
Oxybutynin
*side effects: urinary retention, constipation
What are the side effects of anticholinergic drugs?
Dry as the desert! Everything dries up!
Constipation, tachycardia, tremors, confusion, hallucinations, sedation, urinary retention, hot/dry skin, fever, CNS depression (occurs with large doses of atropine)
Which neurotransmitters are altered in Parkinson's disease?
Dopamine & Acetylcholine
Dopamine is Decreased (symptoms occur when about 80% of stored dopamine is depleted)
Acetylcholine is Activated (increased)
What is the first line drug for tonic-clonic and partial seizures?
Phenytoin
"Funny to say, funny to pee" - urine may turn pink, orange, or red
*Use only NORMAL SALINE with IV phenytoin
*watch for extravasation as it is irritating
*Long term therapy effects: gingival hyperplasia, acne, hirsutism, osteoporosis, blood dyscrasia (sore throat and fever are signs)
Name the enteral routes.
Enteral: drug is absorbed through oral or gastric mucosa or small intestine; 40-60 minutes for drug onset
Oral: PO - by mouth
Sublingual: SL - under the tongue
Buccal: in cheek or sucked on
Rectal
What is the antidote for anticholinergic poisoning?
Physostigmine
*given for atropine overdose
What are the Six Rights of medication administration?
Right patient, right medication, right dose, right time, right route, right documentation
*also check expiration date
What are the classic signs and symptoms of Parkinson's?
TRAP (tremors, rigidity, akinesia, postural instability)
staggering gait, drooling, mood swings ("on-off phenomenon" with levodopa)
Which medication can be used as an add-on drug for partial seizures as well as neuropathic pain?
Gabapentin
*abrupt discontinuation can lead to withdrawal seizures
*causes sedation and visual changes
Name the parenteral routes.
IV - intravenous; fastest delivery into the bloodstream (15-30 min)
IM - intramuscular; thigh, arm, bum
SQ/SC - subcutaneous; into fatty tissue, takes a bit longer to absorb
Intradermal - into the skin (TB test)
Intraarterial - into an artery (ART line)
Intrathecal - into the spine, bypasses the blood/brain barrier (some chemos)
Intraarticular - into a joint (cortisone shot)