Benzonatate

INTRODUCTION

Indications

Relief of nonproductive cough due to minor throat or bronchial irritation from inhaled irritants or colds.

Action

Anesthetizes cough or stretch receptors in vagal nerve afferent fibers found in lungs, pleura, and respiratory passages. May also decrease transmission of the cough reflex centrally. Therapeutic Effects: Decrease in cough.

Adverse Reactions/Side Effects

CNS: headache, mild dizziness, sedation. EENT: burning sensation in eyes, nasal congestion. GI: constipation, GI upset, nausea. Derm: pruritus, skin eruptions. Misc: chest numbness, chilly sensation, hypersensitivity reactions.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess frequency and nature of cough and lung sounds (See Appendix K) to help document whether this drug is effective in reducing cough.

• Monitor signs of hypersensitivity reactions, including pulmonary symptoms (tightness in the throat and chest, wheezing, cough, dyspnea) or skin reactions (rash, pruritus, urticaria). Notify physician immediately if these reactions occur.

• Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

Patient/Client-Related Instruction

• Advise patient to minimize cough by avoiding irritants, such as cigarette smoke, fumes, and dust. Humidification of environmental air, frequent sips of water, and sugarless hard candy may also decrease the frequency of dry, irritating cough.

• Advise patient that any cough lasting more than 1 wk or accompanied by fever, chest pain, persistent headache, or skin rash warrants medical attention.

• Instruct patient or family/caregivers to report other problematic side effects such as severe or prolonged headache, sedation, burning sensation in the eyes, nasal congestion, chills, chest numbness, skin reactions (itching, skin eruptions), or GI problems (nausea, upset stomach, constipation).

Pharmacokinetics

Absorption: Unknown.

Distribution: Unknown.

Metabolism and Excretion: Unknown.

Half-life: Unknown.

Contraindications/Precautions

Contraindicated in: Hypersensitivity to benzonatate. Cross-sensitivity with other ester-type local anesthetics (tetracaine, procaine, and others) may occur.

Use Cautiously in: OB/Lactation: Safety not established; Pedi: Safety not established in children <10 yr.

Interactions

Drug-Drug: Additive CNS depression may occur with antihistamines, alcohol, opioids, and sedative/hypnotics.

Route/Dosage

PO (Adults and Children ≥10 yr): 100 mg 3 times daily (up to 600 mg/day).

Availability (generic available)