Pharmacolohical therapy - B-adrenergic antagonists Flashcards
What are 1st line agents in SA for glaucoma?
Topical B-adrenergic antagonists - B-blockers
- reduce IOP + formation aq humour made by ciliary body
Type of B blockers of Timolol + Levobunolol
- non-selective B1 + B2 adrenergic receptors
Type of B blocker of Betaxolol
B1 selective
How does Betaxolol work?
- reduce IOP to lesser extent than nonselective B-blockers
- parts efficacy related neuroprotective mechanism indepednet of IOP reduction
- cause less excerbation of pulmonary diseases
How are topical B-blockers administered?
twice daily
How can timolol - Timptol -XE be administered?
once daily - gel forming soln
What adverse effect is common with monotherapy with B-blocker?
- Tachyphylaxis
- result in need of combination therapy
Can patients on concurrent systemic B blockers experienc less IOP reduction than patients only on topical B blockers? /
Yes
How can B blockers cause systemic adverse effects?
nasolacrimal drainage + systemic absorption in mucus membranes in nasal-pharyngeal cavity
- route bypasses FPH metbolism = signigicant drug concentrations
Most common pulmonary effect of topical B-blockers
- Bronchospasm
Other adverse effects of B blockers
- pulmonary oedema
- status asthmaticus
- respiratory arrest
Cardiovascular effects of B-blockers
- bradycardia
- hypotension
- CHF excerabtion
As with systemic B blockers, topical b blockers can also cause?
depression and hyperlipidarmia - mass symptoms of hypoglycaemia
C/I of topical B-blockers
- asthma
- COPD
- sinus bradycardia
- 2 / 3rd degree block
- cardiac failure
- hypersentivity
Common adverse effect of B blockers?
- stining upon installation
