Prototype drugs exam 2 Flashcards
Anticholinergic Agents/ Parasympatholytics
atropine
Indications for atropine
Decrease secretions, bradycardia, pylorospasm, ureteral colic, relaxing of bladder, emotional lability with head injuries, antidote for cholinergic drugs, pupil dilation
Actions of atropine
competitively blocks acetylcholine muscarinic receptor sites, blocking the effects of the parasympathetic nervous system.
Pharmacokinetics of atropine
Route- IM
Onset-10-15min
peak- 30min
Duration 4h
Route- IV
Onset- stat
Peak- 2-4 min
Duration- 4h
Route- SQ
Onset- varies
Peak- 1-2h
Duration- 4h
Route- topical
Onset- 5-10 min
Peak- 30-40 min
Duration- 7-14 day
Half-life of atropine
2.5 h, with metabolism in the liver and excretion in the urine
Adverse effects of atropine
blurred vision, mydriasis, cycloplegia, photophobia, palpitations, bradycardia, dry mouth, altered taste perception, urinary hesitancy &retention, decreased sweating, predisposition to heat prostration, (Flushed, hot, dry, mad as the hatter)
Direct-Acting cholinergic agonists
bethanechol (Duvoid, Urecholine)
Indications for bethanechol
Treatment of nonobstructive postoperative and postpartum urinary retention, neurogenic bladder atony in adults and children >8y; diagnosis and treatment of reflux esophagitis in adults and used orally in infants and children for treatment of esophageal reflux.
Action of bethanechol
Acts directly on cholinergic receptors to mimic the effects of Ach, increase tone of detrusor muscles and causes emptying of the bladder.
Pharmacokinetics of bethanechol
Route - oral
onset- 30-90min
peak- 60-90 min
duration- 1-6 h
half-life of bethanechol
metabolism and excretion unkonwn, though to be synaptic.
adverse effects of bethanechol
abdominal discomfort, salivation, nausea, vomiting, sweating, flushing.
Indirect-acting cholinergic agonists
pyridostigmine (Mestinon) & donezpezil (Aricept)
Indications for pyridostigmine
managment of myasthenia gravis; antidote to neuromuscular junction blockers; increases survival after exposure to nerve gas.
Indications for donepezil
management of Alzheimer’s dementia, including severe dementia.
Actions of pyridostigmine
reversible cholinesterase inhibitor that increases the levels of Ach, facilitating transmission at the neuromuscular junction.
Pharmacokinetics of pyridostigmine
Route oral IM IV
Onset 35-45min 15min 5min
Duration 3-6h 3-6 h 3-6 h
Half-life of pyrdostigmine
1.9 to 3.7 hours, metabolized in the liver and tissue and excretion is in the urine.
Adverse effects of pyrdostigmine
bradycardia, cardiac arrest, tearing, miosis, salivation, dysphagia, nausea, vomiting, increased bronchial secretions, urinary frequencty and incontinence.
Actions of donepezil
reversible cholinesterase inhibitor that causes elevation ACh levels in the cortex, which slows the neuronal degradation of Alzheimer’s disease.
Pharmacokinetics of donepezil
Route- oral
Onset- varies
Peak- 2-4 h
Half-life of donepezil
70 hrs; metabolism is in the liver and excretion is in the urine.
Adverse effects of donepezil
Insomnia, fatigue, rash, nausea, vomiting, diarrhea, dyspepsia, abdominal pain, muscle cramps.
Known effects of pilocarpine
Increased secretions in the GI tract and relieve the symptoms of dry mouth that are in seen in Sjogren’s syndrome. Treats glaucoma.
tacrine (Cognex)
a cholinergic drug used to treat Alzheimer’s disease that and was the first drug used to treat Alzheimer’s dementia.
galatmine (Razadyne)
a cholinergic drug used to treat Alzheimer’s disease that use to stop the progression of Alzheimer’s dementia.
rivastigmine (Exelon)
a cholinergic drug used to treat Alzheimer’s disease that is a available in liquid form for easy swallowing.
donepezil (Aricept)
a cholinergic drug used to treat Alzheimer’s disease that has a once a day dosing with a half life of 70 h.
