TRIPROLIDINE AND PSEUDOEPHEDRINE HYDROCHLORIDES

Clinical safety rating: safe

Animal studies have demonstrated safety

How it works

Triprolidine is a first-generation antihistamine that competitively antagonizes histamine at H1 receptor sites, reducing allergic symptoms. Pseudoephedrine is a sympathomimetic amine that acts as a decongestant by stimulating alpha-adrenergic receptors in the nasal mucosa, causing vasoconstriction.

What the body does with it

Metabolism	Triprolidine: Hepatic metabolism via hydroxylation and conjugation. Pseudoephedrine: Partially metabolized in the liver by N-demethylation to an inactive metabolite; primarily excreted unchanged in urine.
Excretion	Triprolidine: Renal excretion of metabolites (approx. 60%) and unchanged drug (less than 5%). Pseudoephedrine: Primarily renal elimination as unchanged drug (70-90%), with minor hepatic metabolism. Fecal excretion is negligible for both.
Half-life	Triprolidine: 5-7 hours. Pseudoephedrine: 4-8 hours (pH-dependent; alkaline urine prolongs half-life). Clinical context: Dose adjustment needed in renal impairment for pseudoephedrine.
Protein binding	Triprolidine: Approximately 90% bound to plasma proteins (mainly albumin). Pseudoephedrine: Minimal protein binding, approximately 20%.
Volume of Distribution	Triprolidine: 2-3 L/kg. Pseudoephedrine: 2.6-3.5 L/kg. Clinical meaning: Indicates extensive tissue distribution.
Bioavailability	Triprolidine: Oral bioavailability ~90%. Pseudoephedrine: Oral bioavailability ~100%.
Onset of Action	Both components: Oral administration, 30-60 minutes.
Duration of Action	Triprolidine: 4-6 hours. Pseudoephedrine: 4-6 hours (up to 8 hours with extended-release formulations). Clinical note: Effect may persist longer in patients with alkaline urine.

Classification & Brands

Dosing & administration

1 capsule (triprolidine 2.5 mg/pseudoephedrine 60 mg) orally every 4-6 hours; not to exceed 4 doses in 24 hours.

Dosage form	CAPSULE, EXTENDED RELEASE
Renal impairment	GFR 30-50 mL/min: administer every 6-8 hours; GFR 10-29 mL/min: administer every 12 hours; GFR <10 mL/min: not recommended (avoid).
Liver impairment	Child-Pugh Class A: no adjustment; Child-Pugh Class B: cautious use, consider dose reduction; Child-Pugh Class C: contraindicated.
Pediatric use	Children 12 years and older: same as adult; Children 6-12 years: 1/2 capsule (triprolidine 1.25 mg/pseudoephedrine 30 mg) every 6 hours; Children 2-6 years: not recommended (safety not established).
Geriatric use	Initiate with 1 capsule every 8 hours, monitor for anticholinergic effects and hypertension; avoid in patients over 65 years with significant cardiovascular conditions.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

CNS depressants may enhance sedative effects May cause marked drowsiness and impair mental and physical abilities.

Breastfeeding	Pseudoephedrine: Excreted in breast milk (M/P ratio ~2.6-3.4); may reduce milk production. Triprolidine: Unknown excretion. Avoid due to potential irritability and decreased milk supply.
Teratogenic Risk	First trimester: Limited human data; animal studies not suggestive of teratogenicity. Avoid due to theoretical risk of vascular disruption from pseudoephedrine. Second/third trimester: Pseudoephedrine may reduce uteroplacental blood flow; association with gastroschisis in some studies. Use only if benefit outweighs risk.

Warnings & precautions

■ FDA Black Box Warning

No FDA black box warning.

Side Effect Profile

Common Effects	Sedation
Serious Effects

Absolute Contraindications

["Hypersensitivity to triprolidine, pseudoephedrine, or any component","Severe hypertension","Severe coronary artery disease","Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOI therapy","Narrow-angle glaucoma","Urinary retention","During or within 2 weeks of MAOI therapy"]

Clinical Precautions

Precautions

["Cardiovascular effects: Use with caution in patients with hypertension, ischemic heart disease, or arrhythmias","Central nervous system stimulation: May cause insomnia, dizziness, or nervousness","Anticholinergic effects: Caution in patients with glaucoma, prostatic hypertrophy, or urinary retention","Drug interactions: Avoid concurrent use with MAOIs or within 14 days of stopping them","Geriatric use: Increased sensitivity to anticholinergic effects"]

Clinical Tips & Counseling

Drug interactions

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