Physostigmine ( * )- @ Miotics, Cholinesterase inhibitor
Drug Name:Physostigmine ( * )- @ Miotics, Cholinesterase inhibitor
List Of Brands:
Indication Type Description:
Drug Interaction
Indication
Adverse Reaction
Contra-Indications
Dosages/ Overdosage Etc
Other Information
Patient Information
Pharmacology/ Pharmacokinetics
Pregnancy and lactation
Drug Interaction:
Cholinesterase inhibitors include-
Reversible - Physostigmine, Demecarium bromide
Irreversible- Echothiophate
Refer - Physostigmine
+ Cholinesterase inhibitors
Carbamate / Organophosphate insecticides/ Pesticides
warn persons on cholinesterase inhibitors who are exposed to these
substances (eg. gardeners, organophosphate plant or warehouse workers)
of systemic effects possible from absorption through respiratory tract or skin
Advice use of respiratory masks, frequent washing and clothing changes
Succinylcholine
use extreme caution before or during general anesthesia to patients on
cholinesterase inhibitors because of possible respiratory and
cardiovascular collapse.
Anticholinestrases systemic
r additive effects aare possible, coadminister topical cholinesterase
inhibitors cautiously, regardless which therapy is added.
Indication:
Glaucoma
Adverse Reaction:
Ophthalmic- iris cysts , burning, lacrimation, lid muscle twitching, conjuntivial and ciliary redness, headache, activation of latent iritis or uveitis, induced myopia with visual blurring,
retinal detachment, lens oacities, conjuntivial thickenening and destruction of nasolacrimal canals.(prolonged use)
Paroxidcal increase in IOP by pupillary block may follow instillation. Alleviate with pupil -dilating
medication.
Systemic- nausea, vomiting, abdominal cramps, diarrhea, urinary incontinence, fainting sweating, salivation, difficulty in breathing, cardiac irregularities.
Contra-Indications:
Contraindications-
Hypersensitivity to cholinesterase inhibitors or any component of the formulation. active inflammation or any inflammatory disease of the iris or clinary body., glaucoma associated with iridocyclitis.
Demacarium- Pregnancy
Echothiophate- most cases of angle-closure glaucoma (due to possibility of increasing angle-block)
Special precautions-
Concomittant therapy- cholinestease inhibitors may be used incombination with adrenergic agents, Beta blockers, carbonic anhydrase inhibitors or hyperosmotic agents.
Narrow angle glaucoma- usewith caution in patients with chronic angle -closure (narrow-angle )glaucoma or in patients with narrow angles, because of the possibility of producing pupillary block and increasing angle blockage.
Special risk patients- use caution inpatients with marked vagotonia, bronchial asthma, spastic GI disturbances, peptic ulcer, pronounced bradycardia/hypotension.revent MI, epilepsy, parkinsonism and other disorders that may respond adversely to vagotonic effects. temporarily discontinue if cardiac irregularities occur.
Ophthalmic ointments- may retard corneal healing
Miosis- usually causes dificluty in dark adaptation. Use caution while driving at night or performing hazardous tasks in poor light.
Gonioscopy- use only when shorter -acting miotics have proved inadequate. Gonioscaopy is recommended prior to use of medication. Routine examination (eg,. slit lamp, ) to lens opacities should accompany therapy.
Concomitant ocular conditions- when an intraocuar inflammatory process is present, breakdown of the blood aqueous barrier from anticholinestaerase therapy requires abstention from or cautious use of these drugs. Use with great caution where there is a history of quiescent uveitis.After long term use blood vessel dilation and resultant greater permeability increase possibly of hyphema during or prior to ophthalmic surgery. Discontinue 3 to 4 weeks before surgery.
Systemic effects- repeated administration may cause depression of the concentration of
cholinesterase in the serum and erythrocytes, with resultant systemic efects. Discontune if
salivation,urinary incontinence ,diarrhea, profuse sweating, muscle weakness, respiratory difficulties , shock or cardiac irregularities occur.
Iris cysts- Iris cysts may form, enlarge and obscure vision (more frequent in children) .The iris cysts usually shrinks upon discontinuance of the miotic,or folowing reduction in strength of the drops or frequency of instillation.
Warnings-
Myasthenia gravis- because of possible additive adverse effects administer demecarrium and echothiophate only with extreme caution to patients with myasthenia gravis who are receiving systemic anticholesterase therapy.
Conversely, use extreme caution in the use of anticholinesterase drugs for the treatment of myasthnia gravis patients who are already undergoing topical therapy with cholinesterase inhibitors.
Surgery- in patients receiving cholinesterase inhibitors, administer succinylchloine with extreme caution before and during general anesthesia. Use prior to ophthalmic surgery only as a considered
risk because of the possible occurence of hyphema.
Pregnancy- contraindiacted in women who are or who may become pregnant, If the drug is used during pregnancy or if the patient becomes pregnant,apparise the patient of the potential hazard to the fetus.
Lactation- because of the potential for serious adverse reactions in nursing infants, decide whether to discontinue nursing or the drug taking into account the importance of the drug to the mother.
Children- safety and efficacy for use in children have not been established.
Dosages/ Overdosage Etc:
Glaucoma
Dosage: Ointment- apply small quanitity to lower fonmix, upto 3 times daily Storage- Keep tightly closed. Protect from heat.
Overdosage- Can cause cholinergic crisis. Atropine sulphate is an appropriate antidote
Other Information:
Seizures- ( 130)
Convulsive disorder is an expression of a sudden excessive disorderly discharge of neurons in either a structurally
normal or diseased cortex. The discharge results in an almost istantaneous disturbance of sensation .loss of
consciousness,comvulsive movement or some combination thereof.
Drugs causing adverse reactions- ( 388 )
1. Amphetamines
2. Analeptics
3. Phenothiazine
4. Isoniazid
5. Lidocaine
6. Theophylline
7. Penicillin
8. Nalidixic acid
9. Physostigmine
10. Vincristine
11. Lithium
Patient Information:
1. Local; irritaion and headaahe may occur at inhaltion of therapy .2. Notify physician if abdiminal cramps, diarrhea,or excesive salivation occurs. 3. Wash hands immediadtely after administration. 4. Use caution while driving at night or performing hazardous tasks in poor light
Ref - USP PDI Vol II 17th Edition (1997)
PHYSOSTIGMINE - Ophthalmic
1.Allergies-
Tell your doctor if you have ever had any unusual or allergic reaction to
physostigmine. Also tell your healthcare care professional if you are allergic to
any other substances such as foods. preservatives or dyes.
2.Pregnancy-
Ophthalmic physostigmine may be absorbed into the body. However, studies
have not been done in humans or animals.
3. Breast-feeding-
Ophthamic physostigmine may be absorbed into the mothers body. However,
this medicine has not been reported to cause any problems in nursing
babies.
4.Children-
Although there is no specific information comparing use of physostigmine
in children with use in other age groups, this medicine is not expected
to cause different side effects or problems than it does in adults.
5.Older adults-
There is no specific information comparing use of physostigmine
in the elderly with use in other age groups
6. Other medicines-
Tell your doctor if you are using any other prescription or non-prescription
(Over-the counter) OTC medicine.
7. Other medical problems-
Make sure you tell your doctor if you have any other medical problems
especially-
Eye disease or problems - physostigmine may make the condition worse.
Pharmacology/ Pharmacokinetics:
Pharmacology-
These indirect-acting agents inhibit the enzyme cholinerterase, potentiating the action of acetylcholine on the parasympathomimetic end organs.
Topical appln. to the eye produces intense miosis and muscle contraction. The intra-ocular pressure is IOP is reduced by a decreased resistence to aqueous outflow.
Pregnancy and lactation:
Pregnancy-
Contraindiacted in women who are or who may become pregnant, If the drug is used during pregnancy or if the patient becomes pregnant, apparise the patient of the potential hazard to the fetus.
Lactation-
Because of the potential for serious adverse reactions in nursing infants, decide whether to discontue nursing or the drug taking into account the importance of the drug to the mother. Children- Safety and efficacy for use in children have not been established.
