CLARINEX-D 12 HOUR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CLARINEX-D 12 HOUR (CLARINEX-D 12 HOUR).
Desloratadine is a long-acting tricyclic histamine antagonist selective for H1-receptor with additional anti-inflammatory properties. Pseudoephedrine is a sympathomimetic amine that acts as a vasoconstrictor via alpha-adrenergic receptors.
| Metabolism | Desloratadine: primarily metabolized by CYP3A4 and CYP2D6 to active metabolite 3-hydroxydesloratadine. Pseudoephedrine: partially metabolized in liver by N-demethylation via CYP450 enzymes; largely excreted unchanged in urine. |
| Excretion | Desloratadine: 40.2% renal (unchanged and metabolites), 41.7% fecal; pseudoephedrine: 70-90% renal (unchanged). |
| Half-life | Desloratadine: 27 hours (terminal), allows once-daily dosing; pseudoephedrine: 4-6 hours (prolonged in alkaline urine). |
| Protein binding | Desloratadine: 83-87% (mainly albumin); pseudoephedrine: negligible binding. |
| Volume of Distribution | Desloratadine: 49 L (approx. 0.7 L/kg), extensive tissue distribution; pseudoephedrine: 2.6-3.5 L/kg. |
| Bioavailability | Desloratadine: 100% (oral); pseudoephedrine: ~100% (oral). |
| Onset of Action | Desloratadine: 60 minutes (oral); pseudoephedrine: 30-60 minutes (oral). |
| Duration of Action | Desloratadine: 24 hours (symptom relief), pseudoephedrine: 4-6 hours (12-hour formulation). |
| Molecular Weight | Desloratadine: 310.8 Da; Pseudoephedrine: 165.23 Da |
| Action Class | Antihistamine (second-generation)/Decongestant combination |
1 tablet (5 mg desloratadine / 120 mg pseudoephedrine) orally every 12 hours.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | Contraindicated in patients with GFR < 60 mL/min due to pseudoephedrine component. |
| Liver impairment | No specific Child-Pugh based adjustments for desloratadine; pseudoephedrine may require caution in severe hepatic impairment. |
| Pediatric use | Not recommended for use in pediatric patients under 12 years of age. |
| Geriatric use | Use with caution; initiate at lower doses due to increased sensitivity to pseudoephedrine and risk of anticholinergic effects. |
| 1st trimester | Avoid. Desloratadine (category C) and pseudoephedrine (category C) have risks; pseudoephedrine associated with gastroschisis and vascular disruption. |
| 2nd trimester | Avoid if possible; pseudoephedrine may reduce uteroplacental blood flow. |
| 3rd trimester | Avoid; pseudoephedrine can cause uterine vasoconstriction and fetal hypoxia. |
Clinical note
Comprehensive clinical and safety monograph for CLARINEX-D 12 HOUR (CLARINEX-D 12 HOUR).
| Placental transfer | Desloratadine and pseudoephedrine cross the placenta; pseudoephedrine is detected in fetal blood. |
| Breastfeeding | Desloratadine is excreted in breast milk in low amounts; pseudoephedrine is excreted and may cause irritability or decreased milk production. Use with caution, preferably lowest dose. |
■ FDA Black Box Warning
None.
| Common Effects | Insomnia, Nervousness, Dizziness, Dry mouth, Pharyngitis, Fatigue, Somnolence (less common than with first-generation antihistamines) |
| Serious Effects | Cardiovascular events (e.g., hypertension, tachycardia, arrhythmias, myocardial ischemia), Cerebrovascular events (e.g., hemorrhagic stroke, especially in patients with hypertension), Seizures, Severe allergic reactions (e.g., anaphylaxis, angioedema), Urinary retention (especially in patients with prostatic hypertrophy), Increased intraocular pressure (angle-closure glaucoma) |
Severe hypertensionCoronary artery diseaseNarrow-angle glaucomaUrinary retention (including from prostatic hyperplasia)Concurrent MAOI therapy or within 14 daysHypersensitivity to desloratadine, pseudoephedrine, or any component
| Precautions | Cardiovascular effects: Use with caution in patients with hypertension, arrhythmias, or ischemic heart disease., CNS stimulation: May cause insomnia, dizziness, or nervousness., Urinary retention: Use with caution in patients with prostatic hypertrophy or bladder neck obstruction., Renal impairment: Reduce dose or avoid in severe renal impairment., Hepatic impairment: Caution in severe hepatic disease. |
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| Lactation Rating |
| L3 (Moderately Safe) |
| Teratogenic Risk | Clarinox-D 12 Hour (desloratadine/pseudoephedrine) is classified as FDA Pregnancy Category C. Desloratadine: No adequate studies in pregnant women; animal studies show no teratogenicity at doses 210 times human exposure, but potential for adverse effects is unknown. Pseudoephedrine: Case reports suggest possible association with gastroschisis at first-trimester exposure; vasoconstriction may reduce uteroplacental blood flow, especially in third trimester. Avoid in first trimester if possible; use only if benefit outweighs risk. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate due to pseudoephedrine's vasoconstrictive effects. Fetal heart rate monitoring via non-stress test may be considered in third trimester. Assess for signs of reduced placental perfusion (e.g., fetal growth restriction) if used chronically. |
| Fertility Effects | No specific human data on fertility effects. Pseudoephedrine may theoretically impair fertility via peripheral vasoconstriction affecting reproductive organs. Desloratadine animal studies showed no impairment. Effects in humans unknown. |
| Food/Dietary | Avoid high-tyramine foods (e.g., aged cheeses, cured meats, fermented foods) as pseudoephedrine may potentiate pressor effects. Taking with food may reduce gastrointestinal irritation. Avoid grapefruit juice; it may increase desloratadine levels. Limit caffeine intake as it can add to CNS stimulation. |
| Clinical Pearls | CLARINEX-D 12 HOUR (desloratadine/pseudoephedrine) combines a non-sedating antihistamine with a sympathomimetic decongestant. Pseudoephedrine can cause hypertension, tachycardia, and urinary retention; avoid in patients with severe hypertension, coronary artery disease, or narrow-angle glaucoma. Desloratadine is the active metabolite of loratadine; it is less sedating than first-generation antihistamines. The 12-hour formulation requires twice-daily dosing. Monitor for CNS stimulation and insomnia, especially in elderly or pediatric patients. |
| Patient Advice | Take one tablet every 12 hours with a full glass of water; do not crush or chew. · Do not exceed 2 tablets in 24 hours. · Avoid alcohol and other CNS depressants while taking this medication. · May cause dizziness or drowsiness; avoid driving until you know how the medication affects you. · Notify your doctor if you have high blood pressure, heart disease, thyroid problems, or difficulty urinating. · Discontinue use and seek medical attention if you experience chest pain, rapid heartbeat, or difficulty breathing. · Do not take with other decongestants or antihistamines without consulting a healthcare provider. |