Drug Interaction:
Interacting drugs- summary
+ Anticholinesterase
Aminoglycoside antibiotics/ Neomycin,streptomycin / Kanamycin
a mild but definite nondeploarizing blocking action which may accentuate neuromuscular block
Atropine/ Belladona derivatives
routine admin. of atropine or belladonna derivatives with these agents suppress the parasympathomimetic ( muscarinic ) symptoms of excessive GI stimulation, leaving
only the more serious symptoms of paralysis of voluntary muscles as sign of leakage
Corticosteroids
anticholinesterase effect antagonised in myasthenia gravis
Depolarizing muscle relaxants /succinyl choline / decamethonium
neostigmine prolong the phase I block of these agents.Use these drugs in myasthenic patients only when definitely indicated. Make careful adjustment of cholinesterase dosage
Local and some anesthetics , / antiarrhythmics
interfere with neuromuscular transmission. Use cautiously if at all , in myastenis patients
Magnesium
has a direct depressant effect on skeletal muscle, and antagonise the beneficial effect of anticholinesterase therapy
Mecamylamine
do not administer to patients receiving ganglionic blocking effect
Methocarbamol
a single report indicates this drug has impaired the effect of pyridostigmine in patient with myasthenia gravis
Succinylcholine
neuromuscular blocking agents effects may be increased. Prolonged respiratory depression with extended periods of apnea occur
Patient Information:
Ref- Advice for the Patient - Drug Information in Lay Language- USPDI (1997)
Antimyasthenics - Systemic
Includes- Ambenonium, Neostigmine, Pyridostigmine
1.Allergies-
Tell your doctor if you have ever had any unusual or allergic reaction to ambenomium,
bromides, neostigmine or pyridostigmine. Also tell your healthcare provider if you are
allergic to any other substances, such as preservatives or dyes.
2.Pregnancy-
Antimyasthenics have not been reported to cause birth defects, however, muscle
weakness has occured temporarily in some new borns babies whose mother took
antimyasthenics during pregnancy
3. Breast-feeding-
Antimyasthetics have not been reported to cause problems in nursing babies
4.Children-
Although there is no specific information comparing use of antimyasthenics
in children with use in other age groups,these medicines are not expected to cause
different side effects or problems in children than in adults.
5.Older adults-
Many medicines have not been studied specifically in older people. Therefore, it
may not be known whether they work exactly the same way they do in younger
adults, or if they cause different side effects or problems in older people
Although there is no specific information comparing use of antimyasthenic
in the elderly to use in other age groups, they are not expected to cause
different side effects or problems in older people than they do in younger adults
6.Other medicines-
Although certain medicines should not be used together at all, in other cases two
different medicines may be used together even interaction might occur. In such
cases your doctor may want to change the dose , or other precautions may be
necessary.
When you are taking an antimyasthenic, it is especially important that
your doctor know if you are taking any of the following-.
Demercarium (eg.Humorsol) or
Echothiophate (eg.Phospholine iodide) or
Malathion (eg.Floropryl ) or
Guanadrel (eg. Hylore ) or
Guanethidine (eg.Ismelin ) or
Mecamylamine (eg.Inversine) or
Procainamide ( eg.Pronestyl ) or
Trimthanaphan ( eg.Arfonald) - the effects of thes medicines may interfere
with the actions of antimyasthenics
7.Other medical problems-
The presence of other medical problems may affect the use of antimyasthenics.
make sure you tell your doctor if you have other any other medical problems,
Intestinal blockage or
Urinary tract blockage or
Urinary tract infection- these medicines may make the condition worse.
Manufacturer Details