TRIPROLIDINE HYDROCHLORIDE AND PSEUDOEPHEDRINE HYDROCHLORIDE
Clinical safety rating: safe
CNS depressants may enhance sedative effects May cause marked drowsiness and impair mental and physical abilities.
Triprolidine is a first-generation antihistamine that competitively antagonizes histamine at H1 receptors, reducing allergic symptoms. Pseudoephedrine is a sympathomimetic amine that directly stimulates alpha-adrenergic receptors, causing vasoconstriction and decongestion.
| Metabolism | Triprolidine: Hepatic via CYP450 enzymes (major metabolites: hydroxylation products). Pseudoephedrine: Partially hepatic (N-demethylation) and renal excretion (55-75% unchanged in urine). |
| Excretion | Triprolidine: ~80% renal (mostly metabolites, <5% unchanged). Pseudoephedrine: ~70-90% renal (43-96% unchanged, depends on urine pH; acidic urine increases elimination, alkaline decreases). Biliary/fecal: negligible for both. |
| Half-life | Triprolidine: 3-5 hours (terminal). Pseudoephedrine: 5-8 hours (terminal, pH-dependent; urine pH 8: ~13 hours, pH 5: ~3 hours). Clinical: normal renal function. |
| Protein binding | Triprolidine: ~90% bound (serum proteins). Pseudoephedrine: ~20% bound (serum proteins). |
| Volume of Distribution | Triprolidine: ~2.5 L/kg (high tissue distribution). Pseudoephedrine: ~2.6-3.5 L/kg (extensive tissue distribution). |
| Bioavailability | Oral: Triprolidine: ~100% (well absorbed). Pseudoephedrine: ~90-100% (well absorbed). |
| Onset of Action | Oral: Triprolidine: 30-60 min. Pseudoephedrine: 30-60 min. |
| Duration of Action | Oral: Triprolidine: 4-6 hours (antihistamine). Pseudoephedrine: 4-6 hours (decongestant). Clinical: doses given q4-6h. |
1 tablet (triprolidine 2.5 mg/pseudoephedrine 60 mg) orally every 4 to 6 hours; maximum 4 tablets per 24 hours.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50 mL/min: administer every 6 hours; GFR 10-29 mL/min: administer every 8 hours; GFR <10 mL/min: avoid use or administer every 12 hours with caution. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50% or extend interval to every 8-12 hours; Child-Pugh Class C: avoid use. |
| Pediatric use | Children 6-12 years: half tablet (triprolidine 1.25 mg/pseudoephedrine 30 mg) orally every 4-6 hours, max 2 tablets per day; Children 2-5 years: consult physician (not typically recommended). |
| Geriatric use | Initiate at half the adult dose (e.g., half tablet) every 6 hours due to increased sensitivity and risk of anticholinergic effects; monitor for dizziness, sedation, and hypertension. |
| 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.
| FDA category | Animal |
| Breastfeeding | Both drugs are excreted in breast milk in small amounts. M/P ratio not reported. Pseudephedrine may reduce milk production by 24% with single doses. Consider benefit versus risk; avoid in nursing mothers with hypertension or if infant is premature. Monitor infant for irritability, insomnia, and tachycardia. |
| Teratogenic Risk |
■ FDA Black Box Warning
None.
| Common Effects | Sedation |
| Serious Effects |
["Hypersensitivity to triprolidine, pseudoephedrine, or any component","Severe hypertension or coronary artery disease","Concurrent use of MAO inhibitors or within 14 days of discontinuation","Narrow-angle glaucoma","Urinary retention","Severe hepatic or renal impairment"]
| Precautions | ["Cardiovascular effects: Pseudoephedrine may cause hypertension, palpitations, tachycardia, and arrhythmias; use with caution in patients with cardiovascular disease.","CNS depression: Triprolidine may cause sedation and impair mental alertness; avoid activities requiring full attention.","Drug interactions: MAO inhibitors, sympathomimetics, anticholinergics, and CNS depressants may potentiate effects.","Elderly and children: Increased sensitivity to anticholinergic effects; avoid in children <6 years unless directed by physician.","Urinary retention: Triprolidine may exacerbate in patients with prostatic hypertrophy or bladder neck obstruction."] |
Loading safety data…
| Tripolidine hydrochloride: FDA Pregnancy Category B. No evidence of teratogenicity in animal studies; no adequate human studies. Pseudephedrine: FDA Pregnancy Category C. In first trimester, case-control studies suggest a slight increased risk of gastroschisis (OR ~1.8-2.0) with vasoconstrictors; avoid in first trimester. In second and third trimesters, risk is low, but high doses may reduce uterine blood flow. Use only if benefit outweighs risk. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate. In third trimester, assess fetal heart rate and uterine contractions if used near term. Watch for signs of uterine hyperstimulation with high doses. For prolonged use, monitor fetal growth via ultrasound. |
| Fertility Effects | No known adverse effects on fertility in humans. Pseudephedrine may theoretically impair spermatogenesis due to vasoconstriction, but clinical data are lacking. Tripolidine has no known effects. |