VA Class:AU350

AHFS Class:

• Antimuscarinics/Antispasmodics 12:08.08

Generic Name(s):

• Methscopolamine Bromide

Chemical Name:

• [7( S )-1α,2β,4β,5α,7β]-7-(3-hydroxy-1-oxo-2-phenylpropoxy)-9,9-dimethyl-3-oxa-9-azoniatricyclo[3,3,1,0^2,4] nonane bromide

Molecular Formula:

• C₁₈H₂₄BrNO₄

Methscopolamine bromide is a semisynthetic quaternary ammonium antimuscarinic.

Methscopolamine bromide is used as an adjunct in the treatment of peptic ulcer disease. As with other antimuscarinics, there are no conclusive data from well-controlled studies that indicate that, in the usually recommended dosage, methscopolamine aids in the healing, decreases the rate of recurrence, or prevents complications of peptic ulcers. In addition, in patients with gastric ulcer, antimuscarinics may delay gastric emptying and result in antral stasis. With the advent of more effective therapies for the treatment of peptic ulcer disease, antimuscarinics have only limited usefulness in this condition. Current epidemiologic and clinical evidence supports a strong association between gastric infection with Helicobacter pylori and the pathogenesis of duodenal and gastric ulcers, and the American College of Gastroenterology (ACG), the National Institutes of Health (NIH), and most clinicians currently recommend that all patients with initial or recurrent duodenal or gastric ulcer and documented H. pylori infection receive anti-infective therapy for treatment of the infection. For a more complete discussion of H. pylori infection, including details about the efficacy of various regimens and rationale for drug selection, see Uses: Helicobacter pylori Infection, in Clarithromycin 8:12.12.92.

Administration

Methscopolamine bromide is administered orally. The drug is preferably given 30 minutes before meals and at bedtime.

Dosage

Adult Dosage

The usual initial adult dosage of methscopolamine bromide is 2.5 mg 3 times daily before meals and 2.5 or 5 mg at bedtime. The manufacturer states that in patients with a history of increased susceptibility to the adverse effects of antimuscarinics, therapy should be initiated at a low dosage. The manufacturer states that an initial total daily dose of 12.5 mg is effective in most patients. Patients with severe symptoms may be given an initial dosage of 20 mg daily, administered in divided 5-mg doses 3 times daily before meals and once at bedtime; the manufacturer states that some patients may tolerate 30 mg daily.

As with other antimuscarinics, higher than recommended dosage of methscopolamine bromide may be required for therapeutic effect. The drug should be carefully titrated until therapeutic effect is achieved or adverse effects become intolerable, using the lowest possible effective dosage.

Pediatric Dosage

If methscopolamine bromide is used in pediatric patients, a dosage of 0.2 mg/kg or 6 mg/m² daily, given in 4 equally divided doses, has been recommended by some clinicians. However, the manufacturer states that safety and efficacy of the drug have not been established in pediatric patients.

Pharmacokinetics

Methscopolamine bromide, like other quaternary ammonium drugs, is incompletely absorbed from the GI tract since it is completely ionized.

Little information is available on the distribution or metabolic fate of methscopolamine bromide in the body. Quaternary ammonium antimuscarinics are completely ionized and possess poor lipid solubility. Accordingly, they do not readily penetrate the CNS or the eye. Methscopolamine bromide, like other quaternary ammonium compounds, is believed to be excreted principally in urine as unchanged drug and metabolites and in the feces as unabsorbed drug. Substantial amounts of orally administered drug are probably eliminated in feces as unabsorbed drug.

Chemistry and Stability

Chemistry

Methscopolamine bromide is a semisynthetic quaternary ammonium antimuscarinic. Methscopolamine bromide is an aminoalcohol ester and the quaternary ammonium derivative of scopolamine. The drug occurs as white crystals or as a white, crystalline powder and is freely soluble in water and slightly soluble in alcohol.

Stability

Methscopolamine bromide tablets should be stored in tight containers at 15-30°C.

Additional Information

For further information on chemistry, pharmacology, pharmacokinetics, uses, cautions, acute toxicity, drug interactions, and dosage and administration of methscopolamine bromide, see the Antimuscarinics/Antispasmodics General Statement 12:08.08.