Drugs Block 3 Flashcards
Atropine
Inhibits parasympathetic nervous system. Produces cylcloplegia.
Also causes failure of eye to focus.
Cocaine
Blocks axoplasmic neuronal reuptake pump of Norepi. Will dialate if sympathetic innervation is intact.
Negative test indicate’s Horner’s syndrome. Test cocaine then amphetamine.
Amphetamine
MOA: Reverses axoplasmic pump stimulating release of norepi. If response = normal postganglionic. If no response to amphetamine = no postganglionic nerve.
Test cocaine then amphetamine.
Nicotine
Activates nicotinic receptor releasing norepinepherine, but also activates parasympathetics causing miosis which is more common.
Pilocarpine
Muscarinic agonist. Used to determine cause of miosis and to treat glaucoma by enhancing aqueous humor drainage through trabecular meshwork and canal of schlemm.
If eye responds with miosis then problem is with nerve (CN III palsy)
If eye does not respond to pilocarpine then problem has to be with the eye itself (Atropinic mydriasis)
Physostigmine
Anticholinesterase that prevents Ach degradation
Use: Used to treat narrow angle glaucoma by enhancing aqueous humor drainage through trabecular meshwork and canal of schlemm
Ectothiophate
Anticholinesterase that prevents Ach degradation
Use: Used to treat narrow angle glaucoma by enhancing aqueous humor drainage through trabecular meshwork and canal of schlemm
Terazosin (-azosin)
Alpha-1 receptor antagonist that is not used to treat eye disease but can have ocular side effects.
Reserpine
Norepinephrine depleting agents that can have occular side effects of miosis/ptosis
Timolol (-olol)
Beta blocker that decreases aqueous humor formation.
Lantanoprost
MOA: Prostaglandin derivative that increases uveo-scleral outflow of aqueous humor (flow through the ciliary muscle).
Most common current treatment for glaucoma
Acetazolamide
Carbonic anhydrase inhibitor decreasing the production of aqueous humor. (also used to decrease CSF production)
Botulinum Toxin
Inhibits acetylcholine release used to treat muscle spasms.
Phenylephrine
Alpha-a agonist.
Used in eye drops to dilate pupils. Also used to reverse ptosis in Horner’s syndrome.
Epinepherine
Increases aqueous humor outflow and inhibits formation of aqueous humor. Used to treat glaucoma.
Trimethoprim
Bacteriostatic - inhibits bacterial DHFR. Has low affinity for mammalian enzyme
Polymixin B
Mechanism - Bind to LPS in the membrane creating holes ultimately leading to the release of cellular components.
Gram negative multidrug resistant coverage
Trifluridine
MOA: Pyrimidine analog effective against acyclovir resistant virus because it can be phosphorylated by host kinases also making it much more toxic and should only be used topically.
Cochlear implant
Small implantable electronic device that acts as acoustic transducer. Can’t restore or create nuclear hearing (cochlea is removed)
Both adults and children are candidates, but children between 2 and 6 are ideal due to auditory nerve degeneration.
Mastoidectomy
Removal of mastoid bone to create a safe ear by irradicating infection. Also remove cholesteatoma.
Done to preserve hearing and vestibular structures.
Reconstruction of middle ear structures.
Panretinal Photocoagulation (PRP)
Thousands of laser spots in supportive retina (retina outside macula) which leads to atrophy and decreased vascularization.
Used to treat Proliferative Diabetic Retinopathy (PDR) by preventing neovascularization
Macrolides: Erythromycin and azithromycin
Mechanism: Inhibits translation by binding 23s rRNA of the 50s subunit
Spectrum: Broad coverage of respiratory pathogens, Chlymidia
Resistance: Increased efflux, hyrolysis of drub by esterases, methylation of drug binding site
Adverse effects: GI discomfort, Hepatic failure, and prolonged QT interval. Inhibitors of CYP 450
Glycerine or Isorbide
Used to dehydrate eye during closed angle glaucoma emergency in conjunction with pilocarpine and acetazolamide
Pyremethamine and Sulfadiazine
Sulfadiazine - blocks pteridine synthetase
Pyrimethamine - blocks parasitic DHFR
Used in conjunction to treat Toxoplasmosis
Polytrim
Trimethoprim- blocks bacterial DHFR
Polymixin b - binds LPS creates holes in membrane (gram -)
Used together to treat bacterial conjunctivitis
Polymixin and Neomycin and Hydrocortisone
Polymixin b - binds LPS creates holes in membrane (gram -)
Neomycin - Blocks translocation of 30s ribosomal subunit
Hydrocortisone - Block phospholipase A2 preventing inflammation
Used to treat bacterail otitis externa
