SIDE EFFECTS
The most common effects associated with antihistamines have been drowsiness sedation, dryness of mucous membranes, and gastrointestinal effects. Serious side effects with oral antihistamines, sympathomimetics, and antitussives have been rare. Other adverse reactions may include:
Dermatologic - urticaria, drug rash, photosensitivity, pruritus.
Cardiovascular - hypotension, hypertension, cardiac arrhythmias,
palpitations.
Central Nervous Systems (CNS) - disturbed coordination, tremor,
irritability, insomnia, visual disturbances, weakness, nervousness, convulsion,
headache, euphoria, and dysphoria.
Genitourinary - urinary frequency, difficult urination.
Gastrointestinal - epigastric discomfort, anorexia, nausea, vomiting,
diarrhea, constipation. Respiratory - tightness of the chest and wheezing, shortness
of breath. Hematologic - hemolytic anemia, thrombocytopenia, agranulocytosis.
DRUG INTERACTIONS
MAO inhibitors may prolong and intensify the anticholinergic effects of sympathomimetic
agents. Patients may develop hyperpyrexia, hypotension, nausea, myoclonic leg
jerks, and coma following coadministration of MAO inhibitors and dextromethorphan.
Thus, concomitant administration of Deconsal® DM Tannate Chewable Tablets
and MAO inhibitors should be avoided (see "CONTRAINDICATIONS").