Pyridostigmine Bromide
Pyridostigmine Bromide Prescribing Information
Pyridostigmine bromide oral solution is useful in the treatment of myasthenia gravis.
Pyridostigmine Bromide Oral Solution, USP is available in following form:
raspberry-flavored, containing 60 mg pyridostigmine bromide per teaspoonful (5 mL). This form permits accurate dosage adjustment for children and “brittle” myasthenic patients who require fractions of 60 mg doses. It is more easily swallowed, especially in the morning, by patients with bulbar involvement.
The size and frequency of the dosage must be adjusted to the needs of the individual patient.
The average dose is ten 5 mL teaspoonfuls daily, spaced to provide maximum relief when maximum strength is needed. In severe cases as many as 25 teaspoonfuls a day may be required, while in mild cases one to six teaspoonfuls a day may suffice.
Pyridostigmine bromide is contraindicated in mechanical intestinal or urinary obstruction, and particular caution should be used in its administration to patients with bronchial asthma. Care should be observed in the use of atropine for counteracting side effects, as discussed below.
The side effects of pyridostigmine bromide are most commonly related to overdosage and generally are of two varieties, muscarinic and nicotinic. Among those in the former group are nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis and diaphoresis. Nicotinic side effects are comprised chiefly of muscle cramps, fasciculation and weakness. Muscarinic side effects can usually be counteracted by atropine, but for reasons shown in the preceding section the expedient is not without danger. As with any compound containing the bromide radical, a skin rash may be seen in an occasional patient. Such reactions usually subside promptly upon discontinuance of the medication.
Pyridostigmine bromide oral solution, USP is an orally active cholinesterase inhibitor. Chemically, pyridostigmine bromide, USP is 3-hydroxy-1-methylpyridinium bromide dimethylcarbamate. Its structural formula is:
The molecular formula of pyridostigmine bromide, USP is C9H13BrN2O2 having a molecular weight of 261.12.
Pyridostigmine bromide oral solution, USP contains 60 mg pyridostigmine bromide per teaspoonful in a vehicle containing 0.23% w/w alcohol, glycerin, lactic acid, sodium benzoate, sorbitol, sucrose, raspberry-flavor (propylene glycol, Nat & Art flavor) and water.
Pyridostigmine bromide inhibits the destruction of acetylcholine by cholinesterase and thereby permits freer transmission of nerve impulses across the neuromuscular junction. Pyridostigmine is an analog of neostigmine (Prostigmin), but differs from it in certain clinically significant respects; for example, pyridostigmine is characterized by a longer duration of action and fewer gastrointestinal side effects.