SIDE-EFFECTS OF DRUGS
USED IN THE MANAGEMENT OF GLAUCOMA
First broadcast on www.provet.co.uk
This information is provided by
Provet for educational purposes only.
You should seek the advice of your
veterinarian if your pet is ill as only he or she can correctly advise on the
diagnosis and recommend the treatment that is most appropriate for your pet.
Several drugs can be used in the
management of glaucoma, providing the eye is not already grossly distended, in
which case surgical drainage may be needed. However, the drugs commonly used
can have serious side-effects which must be monitored.
used in the management of glaucoma either :
- Increase drainage of aqueous from the eye
- Decrease production of aqueous within the
- Carbonic anhydrase inhibitors
- Beta-adrenergic blocking agents
They are useful as a sole method of treatment providing the eye is not
already grossly distended.
The following side-effects can be expected,
especially with high doses :
Acetazolamide is a carbonic anhydrase inhibitor and so it works by
decreasing the hydration of carbon dioxide to produce aqueous.
Common side-effects include :
- Increased thirst
- Increased urine production
- General lethargy
A Beta-adrenergic blocking agent. Side-effects, particularly on high
doses which may occur include :
- Bronchoconstriction - a potentially lethal side-effect.
- Decreased glyconeogenesis and decreased glucagon secretion can lead to
- Cardiac side-effects - arrhythmias. The drug must not be stopped
quickly otherwise arrhythmias can result.
- Hypertension may increase when treatment is stopped.
Similar to Pilocarpine (see below) but it has a longer duration of
Similar to Acetazolamide (see above) but side-effects occur less
Similar to Acetazolamide (see above) but side-effects are said to be much
Pilocarpine is a parasympathomimetic miotic
and it is the drug of choice to reduce intraocular pressure in both
closed-angle and open-angle glaucoma. It increases aqueous drainage by
opeining the trabecular meshwork around the canal of Schlemm.
As one of it's direct effects pilocarpine
increases tear production and saliva production. It also increases sweating.
Pilocarpine impairs vision because during it's period of action the
the eye muscles undergo spasm fixing accommodation and focal length.
Sometimes it causes local irritation when instilled into the eye. Cats are
more likely to develop side-effects than dogs.
Pilocarpine is contra-indicated in :
- Anterior uveitis
- Luxated lens - except possibly
Similar to Befunolol. Timolol is an even more potent Beta-adrenergic
blocker than Propanolol.
Latanoprost is a prostaglandin analogue of PGF 2-alpha that
increases outfow of aqueous fluid through the uvealscleral tract.
Latanoprost is an isopropyl ester prodrug that is inactive until it is
hydrolyzed by esterases in the cornea
Updated January 2016