GU Flashcards
Are anticholinergics muscarinic agonists or antagonists?
antagonists
Example of muscarinic antagonist for reversal of Bethanechol toxicity?
Atropine
MOA of Atropine?
Will help the heart speed up by blocking the cholinergic receptors.
Prototype for muscarinic agonist for urinary retention?
Bethanechol (Urecholine)
Therapeutic use of Bethanechol?
urinary retention
MOA of Bethanechol?
Stimulates the release of Ach which activates the PNS
What are the adverse effects of Bethanechol?
Hypotension, bradycardia, increased tone and motility of GI, exacerbation of asthma, dysrhythmias in patients with hyperthyroidism.
Sx of Bethanechol toxicity?
profuse salivation, lacrimation, visual disturbances, bronchospasms, diarrhea, bradycardia, hypotension, cardiovascular collapse.
What is the tx for Bethanechol toxicity?
Atropine and supportive therapy
How do we evaluate the effectiveness of Bethanechol?
monitor I/Os
Contraindications for Bethanechol?
PUD, urinary or GI obstruction, coronary insufficiency, hypotension, asthma, and hyperthyroidism
How is Bethanechol taken in regards to meals?
PO 1 hour AC or 2 hrs PC to reduce gastric upset
What are the 4 major symptoms of an overactive bladder?
urgency, frequency, nocturia, and urge incontinence.
Prototype for anticholinergic drug for overactive bladder?
Oxybutynin (Ditropan XL, Oxytrol)
Therapeutic use for Oxybutynin?
overactive bladder
Adverse effects of of Oxybutynin?
anticholinergic effects: Xerostomia (dry mouth), blurred vision, photophobia, constipation, hyperthermia
Symptoms of Oxybutynin overdose?
dry mouth, blurred vision, photophobia, hyperthermia, hallucinations, and delirium; the skin becomes hot, dry, and flushed.
What is the reversal agent for Oxybutynin toxicity?
Physostigmine
Available routes for Oxybutynin?
transdermal patch and topical gel
Oxybutynin is contraindicated in who?
patients with glaucoma, intestinal atony, urinary tract obstruction, and tachycardia.
Name 2 examples of PDE5 inhibitors?
Viagra and Cialis
What is PED5 enzyme?
it converts available cGMP into GMP and the erection subsides
Therapeutic uses for Sildenafil (Viagra)?
erectile dysfunction and pulmonary arterial HTN
Is Sildenafil taken in regards to meals?
No, but high fat meals can slow down absorption
When should Sildenafil be taken?
1 hr before sexual activity
Interactions with Sildenafil?
nitrates, alpha blockers, and CYP40 inhibitors.
Adverse effects of Sildenafil?
Hypotension, priapism, HA, dyspepsia, flushing, nasal congestion, diarrhea, rash, dizziness, mild transient visual disturbances, intensification of OSA.
Rare side effects of Sildenafil?
Nonarteritic ischemic optic neuropathy (NION) and sudden hearing loss.
Who should be cautious with Sildenafil?
men with recent MI, stroke, or life threatening dysrhythmia in the past 6 months; resting hypotension (<90/50); resting HTN (>170/110); heart failure; unstable angina
Which PDE5 inhibitor lasts the longest (36 hours)?
Tadalafil (Cialis)
Adverse effects of Taldalafil?
Headache, dyspepsia, back pain, myalgia, limb pain, flushing, nasal congestion. Can also be associated with NAION and sudden hearing loss.
Meds to avoid while taking Taldalfil?
nitrates and alpha blockers except Tamsulosin (Flomax)
Food interactions with Sildenafil?
grapefruit juice
Two types of obstructions that cause BPH?
mechanical and dynamic obstruction
What is a mechanical obstruction?
when there is an overgrowth of epithelial cells
What is a dynamic obstruction?
When there is an overgrowth of smooth muscle cells. The prostate is not enlarged, but still same problem.
Which drug can decrease epithelial overgrowth in BPH?
Finesteride (Proscar)
Therapeutic use for Finasteride?
BPH for individuals with very large prostates
Adverse effects of Finasteride?
Decreases ejaculation volume and libido, gynecomastia.
Black box warning for Finasteride?
teratogenic to male fetus
Effects of Finasteride when taken in smaller doses?
propecia-promotes hair growth
When will Finasteride produce improved urination?
3-6 months
How does Finasteride affect PSA levels?
may decrease them
Interactions with Finasteride?
anticholinergics and testosterone
Which alpha 1 adrenergic antagonist is approved for tx of BPH?
Tamsulosin (Flomax)
Therapeutic use for Tamsulosin?
BPH with small prostates/dynamic obstruction
Off-label use for Flomax?
urinary hesitancy or retention in women
MOA of Flomax?
Relaxes urethra neck and prostate; selective for alpha1a receptors (will not affect BP)
Adverse effects of Tamsulosin?
Abnormal ejaculation (ejaculation failure, reduced volume, retrograde ejaculation)
Interactions with Tamsulosin?
anticholinergics and testosterone
Does Flomax lower PSA levels?
No
When should Flomax be taken?
30 min after same meal QD
How is effectiveness of Tamsulosin evaluated?
noting decreased urinary frequency, hesitancy, urgency, dribbling, nocturia
