brompheniramine

Action

Antagonizes effects of histamine at histamine₁-receptor sites, but doesn't bind to or inactivate histamine. Also shows anticholinergic, antipruritic, and sedative activity.

Availability

Capsules (liquigels): 4 mg

Elixir: 2 mg/5 ml

Suspension: 12 mg/5 ml

Tablets: 4 mg, 8 mg, 12 mg

Tablets (extended-release): 8 mg, 12 mg

Indications and dosages

➣ Symptomatic relief of allergic symptoms caused by histamine release; severe allergic or hypersensitivity reactions

Adults and children ages 12 and older: 4 to 8 mg P.O. three to four times daily, or 8 to 12 mg extended-release tablets P.O. two or three times daily. Maximum dosage is 36 mg/day.

Children ages 6 to 12: 2 mg P.O. q 4 to 6 hours as needed, not to exceed 12 mg/day

Children ages 2 to 6: 1 mg P.O. q 4 to 6 hours p.r.n., not to exceed 6 mg/day

Contraindications

• Hypersensitivity to drug

• Coronary artery disease

• Urinary retention

• Pyloroduodenal obstruction

• Peptic ulcer

• MAO inhibitor use within past 14 days

• Breastfeeding

Precautions

Use cautiously in:

• angle-closure glaucoma, hepatic disease, hyperthyroidism, hypertension, bronchial asthma

• elderly patients

• pregnant patients.

Administration

• Give with food if GI upset occurs.

• Don't break or crush extended-release tablets.

• Shake oral suspension well before measuring dose.

See Check elixir and suspension doses carefully, because the mg/ml varies widely between the two liquids.

Adverse reactions

CNS: drowsiness, sedation, dizziness, excitation, irritability, syncope, tremor

CV: hypertension, hypotension, palpitations, tachycardia, extrasystole, arrhythmias, bradycardia

EENT: blurred vision, nasal congestion or dryness, dry or sore throat

GI: nausea, vomiting, constipation, dry mouth

GU: urinary retention or hesitancy, dysuria, early menses, decreased libido, impotence

Hematologic: hemolytic anemia, hypoplastic anemia, thrombocytopenia, agranulocytosis, leukopenia, pan-cytopenia

Respiratory: thickened bronchial secretions, chest tightness, wheezing

Skin: urticaria, rash

Other: increased or decreased appetite, weight gain

Interactions

Drug-drug. CNS depressants (including opioids and sedative-hypnotics): additive CNS depression

MAO inhibitors: intensified, prolonged anticholinergic effects

Drug-diagnostic tests. Allergy tests: false results

Granulocytes, platelets: decreased counts

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

• Monitor respiratory status.

• Stay alert for urinary retention, urinary frequency, and painful or difficult urination. Discontinue drug if these problems occur.

• With long-term use, monitor CBC.

• Monitor elderly patient for dizziness, sedation, and hypotension.

• If patient takes over-the-counter antihistamines, monitor him closely to avoid potential overdose.

Patient teaching

• Advise patient to take drug with meals if GI upset occurs.

• Instruct patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Caution patient to avoid alcohol while taking drug.

• Urge patient to tell all prescribers which drugs and over-the-counter preparations he's taking.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.