Propylhexedrine (Monograph)

Brand name: Benzedrex
Drug class: Vasoconstrictors
ATC class: R03AA01
VA class: RE102
Chemical name: N,α-dimethyl-cyclohexylethylamine
Molecular formula: C₁₀ H₂₁ N
CAS number: 101-40-6

Introduction

Vasoconstrictor, an aliphatic amine.^a

Uses for Propylhexedrine

Nasal Congestion

Self-medication for temporary relief of nasal congestion associated with the common cold, hay fever, or other allergies.^{101 a b}

As effective as other topical vasoconstrictors.^a

Topical nasal decongestants often preferred for short-term treatment; oral agents preferred for prolonged treatment.^a (See Overuse under Cautions.)

Reduce swelling and facilitate visualization of nasal and pharyngeal membranes prior to surgery or diagnostic procedures.^a

Open obstructed eustachian ostia in patients with ear inflammation.^a

Propylhexedrine Dosage and Administration

Administration

Intranasal Administration

Administer topically to the nasal mucosa as an inhalation.^{a b}

Avoid contamination of the inhaler tip; inhaler is for single-patient use only.^{a b}

Warm drug container in the hands prior to use to increase drug volatility.^a

Inhale vapor through each nostril while head is erect; blow nose thoroughly after 3–5 minutes.^a

Supervise use by children 6–12 years of age.^b

Dosage

The Benzedrex propylhexedrine inhaler delivers 0.4–0.5 mg of the drug in each 800 mL of air.^b

Pediatric Patients

Nasal Congestion

Intranasal

Children ≥6 years of age: 2 inhalations (0.4–0.5 mg) in each nostril no more than every 2 hours.^{a b}

If symptoms are not improved after 3 consecutive days, consult a clinician.^{a b} (See Overuse under Cautions.)

Adults

Nasal Congestion

Intranasal

2 inhalations (0.4–0.5 mg) in each nostril no more than every 2 hours.^{a b}

If symptoms are not improved after 3 consecutive days, consult a clinician.^{a b} (See Overuse under Cautions.)

Prescribing Limits

Pediatric Patients

Nasal Congestion

Intranasal

Children ≥6 years of age: Maximum of every 2 hours; maximum duration of 3 consecutive days.^{a b}

Adults

Nasal Congestion

Intranasal

Maximum of every 2 hours; maximum duration of 3 consecutive days.^{a b}

Special Populations

No special populations dosage recommendations at this time.^{a b}

Cautions for Propylhexedrine

Warnings/Precautions

General Precautions

Overuse

Possible irritation of nasal mucosa and adverse systemic effects (particularly in children) with excessive dosage and/or prolonged or too frequent use.^a Possible rebound congestion (rhinitis, chronic redness and swelling of the nasal mucosa); avoid prolonged use.^{a b} (See Advice to Patients.)

Overdosage following oral ingestion may result in psychotic reactions, palpitation, ventricular extrasystoles, and shock.^a

Sympathomimetic Effects

Possible headache, hypertension, nervousness, and increased ventricular rate.^a Use with caution in patients with thyroid disease (e.g., hyperthyroidism), heart disease, hypertension, or diabetes mellitus.^a

Specific Populations

Pregnancy

Safety during pregnancy not established.^a

Pediatric Use

Safety and efficacy not established in children <6 years of age.^{a b}

Possible irritation of nasal mucosa and adverse systemic effects associated with excessive dosage, prolonged or too frequent use, or inadvertent ingestion of nasal solution.^a

Common Adverse Effects

Burning, stinging, sneezing, increase in nasal discharge. ^{a b}

Drug Interactions

Specific Drugs

Propylhexedrine Pharmacokinetics

Absorption

Bioavailability

Occasionally, absorption may be sufficient to produce systemic effects.^a

Onset

Following intranasal administration, local vasoconstriction usually occurs within 0.5–5 minutes.^a

Duration

Following intranasal administration, local vasoconstriction persists for 30–120 minutes.^a

Elimination

Metabolism

Metabolized in the liver.^a

Elimination Route

Excreted in urine as unchanged drug and metabolites.^a

Stability

Storage

Intranasal

Inhaler

Tight container at 15–30°C.^b Avoid excessive heat.^a

Inhaler remains potent for 2–3 months after first use, depending on the degree of use.^{a b}

Actions

• Structurally and pharmacologically related to amphetamine.^a

• Exact mechanism of action unknown but thought to be similar to amphetamine.^a

• Indirectly stimulates α-adrenergic receptors of the sympathetic nervous system; exerts a minor stimulant effect on β-adrenergic receptors.^a

• Intranasal application constricts dilated arterioles, reduces nasal blood flow and congestion, and may open obstructed eustachian ostia.^a Temporarily improves nasal ventilation and aeration.^a

Advice to Patients

• Importance of replacing or discarding inhaler 2–3 months after first use.^{a b}

• Importance of discontinuing drug and consulting a clinician if nasal congestion worsens or persists for >3 days.^{a b}

• Overuse of nasal inhaler may cause recurrence or exacerbation of nasal congestion; importance of not using more frequently than every 2 hours or for >3 days.^{a b}

• Importance of avoiding contamination of the inhaler.^{a b} To minimize risk of spreading infections, do not share inhaler with other individuals.^{a b}

• Importance of women informing clinician if they are or plan to become pregnant or plan to breast-feed.^a

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.^a

• Importance of informing patients of other important precautionary information.^a (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

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