Drug Guide
Acetaminophen, Clemastine Fumarate, Pseudoephedrine Hydrochloride
Classification
Therapeutic: Allergy, Cold, and Pain Relief
Pharmacological: Combination of analgesic, antihistamine, and decongestant
FDA Approved Indications
- Relief of allergy symptoms such as runny nose, sneezing, itchy eyes, and nasal congestion
- Temporary relief of headache and minor pain associated with cold and allergy symptoms
Mechanism of Action
Acetaminophen: inhibits prostaglandin synthesis in the central nervous system, reducing pain and fever; Clemastine Fumarate: antihistamine that blocks H1 receptors, reducing allergic responses; Pseudoephedrine Hydrochloride: adrenergic agonist that constricts blood vessels in nasal passages, decreasing nasal congestion.
Dosage and Administration
Adult: Follow package instructions; generally, 1-2 tablets every 4-6 hours as needed, not exceeding 8 doses in 24 hours
Pediatric: Consult specific product dosing; generally, not recommended for children under certain ages without physician guidance
Geriatric: Adjust dose based on renal and hepatic function; caution due to increased sensitivity to side effects
Renal Impairment: Use with caution; dose adjustment may be necessary
Hepatic Impairment: Use with caution due to acetaminophen component; monitor liver function
Pharmacokinetics
Absorption: Rapid from gastrointestinal tract
Distribution: Widely distributed, crosses the blood-brain barrier
Metabolism: Acetaminophen: primarily hepatic; Clemastine: hepatic CYP enzymes; Pseudoephedrine: minimal hepatic metabolism
Excretion: Renal, primarily as conjugates of acetaminophen and metabolites
Half Life: Acetaminophen: 2-3 hours; Clemastine: approximately 12-19 hours; Pseudoephedrine: 6-12 hours
Contraindications
- Hypersensitivity to any component
- Severe hepatic impairment (acetaminophen)
- Prostate hypertrophy, urinary retention (pseudoephedrine)
Precautions
- Use caution in MAOI use, hypertension, cardiovascular disease, glaucoma, and elderly; monitor for anticholinergic effects from clemastine
Adverse Reactions - Common
- Drowsiness, dizziness (Common)
- Dry mouth, blurred vision (Common)
Adverse Reactions - Serious
- Respiratory depression, hepatotoxicity (acetaminophen overdose) (Serious but less common)
- Serious allergic reactions, tachycardia, hypertension (pseudoephedrine) (Serious but less common)
Drug-Drug Interactions
- MAOIs (risk of hypertensive crisis with pseudoephedrine)
- Other CNS depressants (additive drowsiness)
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor for allergic reactions, drowsiness, blood pressure, and signs of overdose
Diagnoses:
- Risk for injury due to dizziness or drowsiness
- Ineffective airway clearance if allergic reactions occur
Implementation: Administer as directed, monitor patient response, advise caution with operating machinery
Evaluation: Assess relief of symptoms, monitor for adverse effects
Patient/Family Teaching
- Do not exceed recommended dose to avoid hepatotoxicity
- Caution when operating machinery due to drowsiness
- Report signs of allergic reactions or unusual side effects
- Inform about potential increase in blood pressure with pseudoephedrine
Special Considerations
Black Box Warnings:
- Potential for hepatotoxicity with overdose or chronic use of acetaminophen
Genetic Factors: Metabolism of drugs may vary with genetic polymorphisms
Lab Test Interference: None significant
Overdose Management
Signs/Symptoms: Nausea, vomiting, abdominal pain, hepatotoxicity, CNS depression
Treatment: Immediate assessment, activated charcoal if recent ingestion, acetylcysteine for acetaminophen overdose, symptomatic treatment as needed
Storage and Handling
Storage: Store in a cool, dry place away from light
Stability: Stable within expiration date when stored properly