158 Section 3/ Drugs Acting on ANSthus reduces intraocular pressure. Thus it is
useful in treatment of glaucoma.
Pilocarpine when given IV increases the
flow from salivary gland and other exocrine
glands. Bronchial smooth muscle and
intestinal smooth muscle contract. Small
doses generally cause fall in BP, but higher
doses elicit rise in BP and tachycardia (which
is due to ganglionic stimulation).
Therapeutic Uses
a. Open angle glaucoma.
b. Angle closure glaucoma.
c. Ocular surgery.
d. To counteract mydriasis.
e. Diagnosis of Adie’s tonic pupil.
f. Accommodative esotropia.Adverse Reactions
- Potentially life threatening effects: Some
commercially available preparation of
pilocarpine contain sodium bisulphite
which may cause allergic reactions
including anaphylaxis and severe
asthmatic episode. - Acute overdosage: The clinical
symptoms may include nausea,
vomiting, diarrhoea, abdominal pain.
In addition frequent urination,
excessive salivation, lacrimation,
sweating, bronchoconstriction, nasal
congestion. Severe pilocarpine toxicity
may produce tremors, muscle
weakness, bradycardia, cardiac
arrhythmia, hypotension etc. - Severe or irreversible adverse effect:
Some patient with peripheral retinal
degeneration may develop retinal
detachment. A sudden drop of
intraocular pressure indicates that
retinal detachment has occurred.- Symptomatic adverse effects: Topical
pilocarpine therapy produces blurred
vision or myopia, poor vision in dim
light or sometime painful spasm. Many
patients on pilocarpine may experience
ciliary or conjunctival congestion,
headache, photophobia. Some patient
may develop pupillary dilatation
following use of pilocarpine.
Ibopamine (2% eye drop) is recently
introduced newer compound, producing dose
dependent mydriasis endowed with very
interesting characteristics: rapid onset, marked
pupil dilatation and rapid return to normal
pupillary diameter. This rapid return to normal
pupillary diameter after its diagnostic
application in eye offers significant advantages
compared to other currently available
mydriatics. Ibopamine is well absorbed
through the cornea, it is rapidly hydrolyzed by
esterases to epinine and the mydriatic effect is
correlated with the concentration of epinine in
the aqueous humor.
It is approved for mydriasis in ocular
examination and surgery and for the early
diagnosis of glaucoma.
ARECOLINE
It is obtained from the betel nut ‘Areca
catechu’ and has got muscarinic and weak
nicotinic actions. It has no therapeutic value
except for chewing to promote salivary
secretion and in pan masala etc.ANTICHOLINESTERASES
These are the drugs which act by inhibiting
the enzymes true and pseudocholinesterase
and thereby produce an accumulation of