TRANS 063 EENT PHARMA Flashcards
Mydriatic vs Cycloplegic
• Mydriatic → induces dilation of pupils
• Cycloplegic → induces paralysis of ciliary muscle, resulting in
loss of accommodation
• Mostly anticholinergic agents
Tropicamide, Atropine, Homatropine, Cyclopentolate
what drug class?
MYDRIATIC/ CYCLOPLEGIC AGENTS
• Widely used to induce mydriasis to facilitate dilated
fundoscopy
• Blocks muscarinic M4 receptors on the iris sphincter muscle
and ciliary muscle, causing pupillary dilation and paralysis of
ciliary muscle
TROPICAMIDE
Onset of action and duration of effect of tropicamide?
• Onset of action: 20-30 minutes
• Duration of effect: 4-6 hours
• AE: Stinging, irritation, blurred vision, dry mouth, headache,
increased IOP
Most potent mydriatic with the longest duration of action (7
days)
• Used to dilate the pupil for dilated eye examinations
• Used to treat uveitis and iritis to immobilize the ciliary muscle
and prevent or break down adhesions
• AE: Stinging, irritation, blurred vision, dry mouth, headache,
increased IOP
Atropine
- Inactive carbonic anhydrase and sodium pumps, decreasing aqueous humor production → decreased IOP
- AEs: Blurring of vision, bitter taste, dry eyes, irritation, headache
- CARBONIC ANHYDRASE INHIBITORS (ACETAZOLAMIDE, BRINZOLAMIDE)
- Considered first-line treatments for glaucoma
- Increase drainage of aqueous humor
- Once-daily dosing
- Notable AE: lengthening of eyelashes, increase in vellus hair, darkening of eyelid skin and iris color, puffy eye appearance
Sometimes used off label for lengthening the eyelashes
- PROSTAGLANDIN ANALOGS
LATANOPROST, BIMATOPROST, TRAVOPROST
- α2 effects → IOP reduction, neuroprotection (?)
- Decrease aqueous humor production and increases trabecular outflow
- AE: Dry mouth, tiredness, fatigue, blurred vision light sensitivity, tachyphylaxis (with apraclonidine)
- ALPHA AGONISTS
APRACLONIDINE, BRIMONIDINE
Block beta1 receptors in the ciliary epithelium, decreasing aqueous humor production
• AEs: Corneal epithelial erosions, corneal anesthesia
- BETA AGONISTS
TIMOLOL
Treatment/Management for corneal erosions, corneal abrasions?
Antibacterial. Takot tayo sa infection.
Commonly used ocular antibiotics?
Usually quinolones. Ofloxacin, moxifloxacin, levofloxacin or yung ginagawang first-line tobramycin at si tobramycin with dexamethasone. Sikat na brand is Tobramycin (TOBREX) and si Tobramycin with Dexamethasone (TOBRADEX).
Bakit may dexamethasone? Anti-inflammatory. Pero pag corneal abrasion hindi tayo gumagamit ng steroid. Plain lang na antimicrobial bakit kaya?
Kasi yung dexamethasone will prevent the normal healing process. Diba anti-inflammatory siya. Eh kailangan mo rin yung inflammatory, yung recruitment ng inflammatory cells para gumaling yung cornea.
Kailan ka gagamit ng eye ointment kalian ka gagamit ng eye drops?
Eye ointment pag kailangan mo ng occlusion(?). Gusto mo yung medyo lubricating effect or you want an increased contact time between the corneal tissue and the medicine. Pero kung hindi naman important yung longer contact time pwede nang eye drops.
• First-line treatment for many causes of ocular irritation, in particular for dry eye
• Topical eye drops or eye gels which are used in dry eye conditions (keratoconjunctivitis sicca/ dysfunctional tear syndrome)
Some can be over-the-counter, some can only be procured by prescription.
Gels and ointments are reserved for more severe cases kasi mas mahaba nga yung contact time sa cornea vs using ordinary eye drops.
B. OPHTHALMIC LUBRICANTS
• “Artificial tears”
- Derivative of hyaluronic acid
- Humectant, lubricant and hypoosmotic
- Promotes corneal epithelial repair and controls localized inflammation
SODIUM HYALURONATE
• Demulcent that forms protective layer over eyelid mucosa, relieve inflammation and irritation
• Demulcents: high-molecular weight polymers that mimic mucins and act to lubricate, protect and provide viscosity to eye drops
Another common ingredient or common lubricant.
POLYTHYLENE GLYCOL (PEG)/ PROPYLENE GLYCOL
• Hydrophilic polymers that coat and protect the eye
• Hydrogels that crosslink upon contact with the ocular surface to increase tear clearance times
• Must be mixed with other compounds because they are too viscous to instill alone onto the ocular surface
Madalas niyo mae-encounter
Similar to polyethylene glycol
Madalas in combination
HYROXYMETHYLCELLULOSE, HYDROXYPROPYLCELLULOSE AND HYPROMELLOSE
Common preservatives in artificial tears?
benzalkonium chloride
Inhibits voltage-gated sodium channels on neuronal membranes, inhibiting action potential generation, nerve signal propagation and transmission
• Widely used in performing to provide anesthesia during the performance of ophthalmologic procedures
OCULAR ANESTHETIC: PROPARACAINE
onset of action and duration of effect of proparacaine
- Onset of action: within 30 seconds
* Duration of effect: 10-15 minutes
- H3 receptor antagonist
- Exact MOA is unknowm (increased cochlear blood flow)
- May have some benefit in reducing symptoms of vertigo and Meniere’s disease
- Genereally well-tolerated with low risk of adverse events
- Usual dose: 24-48 mg per day in 2-3 divided doses
- BETAHISTINE
Triad of Meniere’s disease:
hearing loss, tinnitus, vertigo
- MOA: Inhibits vascular smooth muscle contractions by blocking L-type and T-type voltage-gated calcium channels
- Binds to dopamine D2 receptors, histamine H1 receptors and Ach receptors
- Used in the treatment of vertigo, Meniere’s disease, and motion sickness
CINNARIZINE
o Lipophilic and cross the blood-brain barrier
o Have antimuscarinic effects
o Cause sedation because they are lipophilic. The more lipophilic drugs are, the easier they can cross the blood brain barrier, thereby, exhibiting the CNS adverse effects such as sedation.
Older first-generation agents of anti histamines
What drug class? Cetirizine, Levocetirizine, Loratadine, Desloratadine, Ebastine, Bilastine
second generation anti histamine
- Still commonly used over-the-counter drugs
- May prevent and treat symptoms of allergic reactions and dry up nasal secretions but markedly causes sedation
- Should not be used by persons who are driving or operating machinery
- FIRST-GENERATION ANTIHISTAMINES
DIPHENHYDRAMINE, CHLORPHENAMINE, HYDROXYZINE
may be used to suppress extrapyramidal side effects of first-generation antipsychotic drugs
• Diphenhydramine
- Used mainly for the treatment of allergic rhinitis and chronic urtacrial
- Provides the same efficacy as first-generation antihistamines but with little to nosedating effect
- SECOND-GENERATION ANTIHISTAMINES
LORATADINE, CETIRIZINE, LEVOCETIRIZINE
• MOA: Agonists of alpha adrenergic receptors → Vasoconstriction
• Commonly used in patients where clogged nose is a problem
It reduces blood flow. Mas konti ang secretions kung mababa ang blood flow.
C. NASAL DECONGESTANTS
Systemic: PHENYPROPANOLAMINE, PHENYLEPHRINE (tablet)
Local: OXYMETAZOLINE (nasal spray)
rebound congestion if used for a long period of time
o Pooling of secretions in patients with COPD
Oxymetazoline
- Very effective for the treatment of allergic rhinitis with potent anti-inflammaotyr properties
- Results in significant reduction in mediator and cytokine release along with a significant inhibition in the recruitment of basophils, eosinophils, neutrophils, and mononuclear cells to nasal secretions
- Significantly improves quality of life and sleep of patient with allergic rhinitis
- Superior to oral H1 antihistamines in controlling nasal sympotms, including nasdal congestion, with no significant difference in the relief of ocular sympyoms
INTRANASAL STEROIDS
adverse effects of Budesonide and Beclomethasone
o Potential to suppress growth in children (particulary Budesonide and Beclomethasone; less likely with Mometasone furoate and Fluticasone propionate)
• Commonly present as active ingredients of commercially-available moputhwashes or gargles
• May provide soothing effects or temporary relief to symptoms of pharyngitis
Madalas ‘di ba nagrereseta ng pangmumog for symptomatic relief or adjunctive treatment. Let’s say for acute bacterial tonsillopharyngitis, the antibiotic of choice is amoxicillin. Kaya lang, it will not give symptomatic relief for difficulty of swallowing and pain kaya madalas nagbibigay ng other preparations. May soothing effect kasi or inherent antibacterial action.
E. ORAL ANTISEPTICS AND OTHER PREPARATIONS
CHLORHEXIDINE, HEXETIDINE
• Broad-spectrum antimicrobial effective against gram-positive, gram-negative bacteria and fungi
Some say it also has antiviral properties pero ‘pag oral kasi di pa ganun ka-established. Mayroong hospital cleaning agents, hospital-grade disinfectants, na ito ang active ingredient. Iba syempre ‘yung preparation ng pharmacologic sa tao.
• Positively-charged molecule that binds to the negatively-charged sites on the cell wall. It destabilizes the cell wall and interefere with osmosis.
• Both bacteriostatic and bactericidal, depending on concentration
CHLORHEXIDINE GLUCONATE
• Broad-spectrum antimicrobial effective against bacteria and fungi
• Similar mechanism of action to chlorhexidine
• Adverse effects:
o Transient anesthesia – helps to the pain
o Irritation
o Sensitization
o Taste disturbances
- HEXETIDINE
Bactidol – brand name
