Download Dear Notetaker - Home Sign In Page

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Drug interaction wikipedia, lookup

Neuropharmacology wikipedia, lookup

Theralizumab wikipedia, lookup

Neuropsychopharmacology wikipedia, lookup

Bilastine wikipedia, lookup

Prescription costs wikipedia, lookup

Pharmacogenomics wikipedia, lookup

Toxicodynamics wikipedia, lookup

Cannabinoid receptor antagonist wikipedia, lookup

Nicotinic agonist wikipedia, lookup

Psychopharmacology wikipedia, lookup

Stimulant wikipedia, lookup

Norepinephrine wikipedia, lookup

Discovery and development of beta-blockers wikipedia, lookup

BHS 254.2
Notetaker: Melissa Milbrandt
Date: 2/8/2016
Phenylephrine continued
o No cycloplegia or blockade of active light reflex because there is no effect on muscarinic
receptors: need to add Tropicamide to get these effects
o Increased effect with LA due to better absorption
o Sympathetic tone varies in different people, is decreased in older people
o Decreased effect in dark irides
o Even 1/8% can rarely cause angle closure
o Counteracts miotics, can be used in 2.5% for examining open angle glaucoma patient on
o Horner’s syndrome
 Sympathetic denervation somewhere along the pathway from the CNS to the
eye, prevents information from CNS from getting to effector cells in the eye
 Three characteristic signs: ptosis, miosis, facial anhydrosis
 Phenylephrine will treat ptosis from Horner’s
 Diagnosis: effector cells are supersensitive to sympathetic stimulation –
adrenergic agonists cause exaggerated response
 Only accurate in 71% of eyes with Horner’s
o 10% dose after local anesthetic can be used to break posterior synechiae
o 2.5% can be used to treat miotic cysts from Acetylcholinesterase Inhibitor
o Toxicities
 Contraindications: thyrotoxicosis, coronary artery disease, hypertension
(especially with 10% solution, but still caution with 2.5%)
 Drug interactions: tricyclic antidepressants, MAO inhibitors, guanethidine,
 These already enhance action of NE or adrenergic agonists on their own,
Phenylephrine will add to it
 Systemic effects
 CNS stimulation, headache
 CV effects: hypertension, subarachnoid hemorrhage, ventricular
arrhythmias, tachycardia, reflex bradycardia, blanching of the skin (due
to vasoconstriction)
 Local and ocular effects
 Transient pain
 Excessive lacrimation
 Keratitis
 Liberation of iris pigment (floaters, especially with older patients with
dark irides)
 Post-dilation miosis (especially in older patients)
 Rebound congestion (rebound hyperemia) due to conjunctival hypoxia
from vasoconstriction
 Angle closure
Apraclonidine (Iopidine) 0.5%, 1.0%
o Alpha agonist, some selective for alpha-2
BHS 254.2
Notetaker: Melissa Milbrandt
Date: 2/8/2016
Main mechanism: stimulates alpha-2 post-synaptic receptors, inhibits adenylate cyclase,
decrease cAMP, decrease aqueous humor production in ciliary body
Secondary mechanism: increase uveoscleral outflow, but not through remodeling
1% is approved for use with argon laser trabeculoplasty, argon laser iridotomy, and
Nd:YAG posterior capsulotomy to bring down increased IOP right after these procedures
o 0.5% can be used for long term use reduce IOP in primary open angle glaucoma (POAG)
 There is some alpha-1 stimulation, so cannot be used in patients with narrow
angles because of the risk of angle closure with mydriasis
o Diagnosis of Horner’s syndrome
 Alpha agonist – not as reliable in direct acting mechanisms
 1% can dilate Horner’s eye more completely than non-Horner’s eye because the
dilator muscle is super sensitive to stimulation
o Adverse effects
 Allergic reactions in 20-50% - hyperemia, increased lacrimation, etc. but it is
more of an irritation response to the drug itself than an immunologic response
 Some alpha-1 stimulation, leading to mydriasis, lid retraction, and conjunctival
 Systemic effects: dry mouth, fatigue, lethargy, headache, symptoms of head
o Available in 0.15% or 0.2% or as Alphagan P in 0.1% and 0.15% (P = purite)
o Highly selective alpha-2 adrenergic receptor agonist, most patients do not see any apha1 effects
o Decreased concentration results in fewer side effects while keeping the beneficial
o Antiglaucoma treatment
 Decrease aqueous production
 Increase uveoscleral outflow (but probably not due to remodeling)
 May be neuroprotective (inhibit excitotoxicity) in glaucoma patients, method is
not clear
BHS 254.2
Notetaker: Melissa Milbrandt
Clicker Questions
Date: 2/8/2016
BHS 254.2
Notetaker: Melissa Milbrandt
Date: 2/8/2016
BHS 254.2
Notetaker: Melissa Milbrandt
Date: 2/8/2016