HEXOCYCLIUM METHYLSULFATE (PDH)
· Pharmacologic classification: anticholinergic
· Therapeutic classification: antimuscarinic, gastrointestinal antispasmodic
Available by prescription only
Tablets: 25 mg
Indications, route and dosage
Adjunctive therapy in peptic ulcer
Adults: 25 mg q.i.d. before meals and h.s.
Contraindications and precautions
Hexocyclium is contraindicated in patients with narrow-angle glaucoma, because drug-induced cycloplegia and mydriasis may increase intraocular pressure; in patients with obstructive uropathy, obstructive GI tract disease, severe ulcerative colitis, myasthenia gravis, paralytic ileus, intestinal atony, or toxic megacolon, because the drug may exacerbate these conditions; in patients with known hypersensitivity to anticholinergics; and in patients who are allergic to tartrazine or aspirin.
Administer hexocyclium cautiously to patients with autonomic neuropathy, hyperthyroidism, coronary artery disease, cardiac arrhythmias, congestive heart failure, or ulcerative colitis, because drug may exacerbate symptoms of these disorders; to patients with hepatic or renal disease, because toxic accumulation can occur, to patients over age 40, because the drug may increase the glaucoma risk; to patients with hernia associated with reflux esophagitis, because the drug may decrease lower esophageal sphincter tone; and in humid environment, because the drug may predispose the patient to heatstroke.
Concurrent administration of antacids decreases oral absorption of anticholinergics. Administer hexocyclium at least I hour before antacids.
Concomitant administration of drugs with anticholinergic effects may cause additive toxicity.
Decreased GI absorption of many drugs has been reported after the use of anticholinergics (for example, levodopa and ketoconazole). Conversely, slowly dissolving digoxin tablets may yield higher serum digoxin levels when administered with anticholinergics.
Use cautiously with oral potassium supplements (especially waxmatrix formulations) because the incidence of potassium-induced GI ulcerations may be increased.
Effects on diagnostic tests
· CNS: headache, insomnia, drowsiness, dizziness, confusion or excitement (in elderly patients), nervousness, weakness.
· CV: palpitations, tachycardia, orthostatic hypotension.
· DERM: urticaria, decreased sweating or anhidrosis, other dermal manifestations.
· EENT: blurred vision, mydriasis, increased ocular tension, cycliplegia, photophobia.
· GI: dry mouth, dysphagia, heartburn, taste loss, nausea, constipation, vomiting, abdominal distention, paralytic ileus.
· GU: urinary retention, confusion or excitement, or curare-like symptoms develop.
Overdose and treatment
Clinical signs of overdose include curare-like symptoms and such peripheral effects as dilated, non-reactive pupils; blurred vision; flushed, hot dry skin; dryness of mucous membranes; dysphagia; decreased or absent bowel sounds; urinary retension; hyperthermia; tachycardia; hypertension; and increased respiration.
Treatment is mainly symptomatic and supportive, as needed. If the patient is alert, induce emesis (or use gastric lavage) and follow with a saline cathartic and activated charcoal to prevent futher drug absorption. In severe cases, physostigmine may be administered to block hexocyclium’s antimuscarinic effects. Give fluids, as needed, to treat shock. If urinary retention occurs, catheterization may be necessary.
Beside those relevant to all anticholinergics, consider the following recommendation.
Some hexocyclium preparations contain tartrazine dye and may cause allergic reactions, especially in patients who are sensitive to aspirin.
Hexocyclium should be administered cautiously to elderly patients. Lower doses are indicated.
Hexocyclium in not intended for use in children.
Hexocyclium may be excreted in breast milk, possibly resulting in infant toxicity. Breast-feeding women should avoid this drug. Hexocyclium may also decrease milk production.