Pyridostigmine (Br) is a quaternary ammonium cholinesterase inhibitor. Pyridostigmine (Br) is a muscular stimulant. It has longer duration of action than that of neostigmine. Pyridostigmine (Br) is used in the chronic management of myasthenia gravis.Pyridostigmine (Br) is also used to reverse the actions of nondepolarizing neuromuscular blockers after surgery. Pyridostigmine was approved by the FDA in 1955.
. It is of Synthetic origin and belongs to Quaternary Ammonium. It belongs to Cholinestrase inhibitor pharmacological group on the basis of mechanism of action and also classified in Antidotes and Cholinergic Agonist pharmacological group.The Molecular Weight of Pyridostigmine (Br) is 261.10. It is weakly alkaline drug, 4.13% solution of the drug is isotonic and Its pKa is strongly basic.
Oral absorption of Pyridostigmine (Br) is found to be 45.5% ±4.5. Volume of distribution is found to be 0.53 - 1.8 l/kg and plasma protien binding is negligible. Renal Excretion accounts for 90% and plasma half life is 0.38 - 1.9 hr.
Pyridostigmine (Br) is known to interact with other drugs, the details of drug interactions is as follows:
Drug Details Severity Onset Management Chloroquine Chloroquine Colistin (Sulphate & Sulphomethate Na) Disopyramide Gentamicin Hydroxychloroquine (Sulphate) Hydroxychloroquine (Sulphate) Kanamycin (Acid Sulphate) Lithium lithium interfere with neuromuscular conduction Methocarbamol Methocarbamol may inhibit the effect of pyridostigmine bromide. Methocarbamol should be used with caution in patients with myasthenia gravis receiving anticholinesterase agents. Methylprednisolone coadministration with corticosteroids such as methylprednisolone result in profound weakness ventilation Neomycin Oxytetracycline (Dihydrate) Pantothenic Acid Pantothenic Acid may increase the effects of Pyridostigmine (Br). Penicillamine coadministration may develop myasthenia gravis Polymyxin B (Sulphate) Procainamide (HCl) Procainamide (HCl) Antiarrythmic drugs such as procainamide block the acetylcholine receptor Propafenone (HCl) Propranolol (HCl)
coadministration with beta blockers have the potential to aggravate the symptom of myasthenia gravis and also reports of bradycardia and hypotension ventilation Quinidine Antiarrythmic drugs such as quinidine block the acetylcholine receptor Streptomycin Trimeprazine (Tartrate) Verapamil (HCl) coadministration with ca channel blockers such as verapamil may produce an enhance muscle block. manage with Edrophonium
These interactions are sometimes beneficial and sometimes may pose threats to life. Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Interference in Pathology
No data regarding the pathological interferences produced by Pyridostigmine (Br) is available.
The severe or irreversible adverse effects of Pyridostigmine (Br), which give rise to further complications include Hallucinations, Anxiety, Epilepsy, Disorientation, Loss of consciousness.
The signs and symptoms that are produced after the acute overdosage of Pyridostigmine (Br) include Bradycardia, Diarrhea, Dizziness, Sweating, Abdominal pain, Salivation, Depolarizing block.
The symptomatic adverse reactions produced by Pyridostigmine (Br) are more or less tolerable and if they become severe, they can be treated symptomatically, these include SweatingX.
Pyridostigmine (Br)'s dosage details are as follows:
2 to 5 mg/dose 3.5 (3.5) 2.4 hourly IV,IM 60 to 180 mg 120 (120) As recommended. PO In Divided doses for Myasthenia Gravis
300 to 1200 mg 750 (750) As recommended. PO In Divided doses for Myasthenia Gravis
Paedriatic Dosage ( 20 Kg. )
3 mg/kg 3 (3) 6 hourly Oral Adjust Dose as per response obtained
Neonatal Dosage ( 3 Kg. )
0.625 to 3.75 mg/kg 2.2 (2.1875) 6 hourly Oral Initial dose , then adjust according to response
High Risk Groups
If prescribing authority justifies the benefits of the drug against the possible damages he/she should reevaluate them and consult the reference material and previous studies.
Warning / Precautions
Pyridostigmine should be used with caution in patients with any pre-existing stomach disorders, kidney or urinary problems, ulcers, asthma, epilepsy, heart diseases, thyroid disorders or allergies especially to bromides or anticholinesterases. Notify the doctor if this medication appears to be losing its effect. In some cases, people become insensitive to the medication and it must be stopped for a brief period. It should be used only if clearly needed during pregnancy or lactation.
Store Between 15°C-30°C. Do not Freeze. Protect from Sunlight and Moisture.
Store Between 15°C-30°C. Protect from Sunlight and Moisture.
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