Generic Name

Pyrilamine Maleate

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Classification

FDA Approved Indications

N/A

Mechanism of Action

Pyrilamine Maleate is an H1 histamine receptor antagonist that blocks the effects of histamine at H1 receptor sites, thereby reducing allergic responses.

Dosage and Administration

Adult: Dosage varies; typically 25-50 mg orally every 4-6 hours as needed, not exceeding 300 mg/day.

Pediatric: Use with caution; dosage is usually 1 mg/kg body weight per day divided into multiple doses.

Geriatric: Start at lower doses due to increased sensitivity and risk of adverse effects.

Renal Impairment: Adjust dosage based on renal function; consult prescribing information.

Hepatic Impairment: Use caution; no specific guidelines, monitor for efficacy and toxicity.

Pharmacokinetics

Absorption: Rapidly absorbed from the gastrointestinal tract.

Distribution: Widely distributed; crosses the blood-brain barrier, causing sedation.

Metabolism: Metabolized in the liver.

Excretion: Excreted primarily in urine.

Half Life: Approx. 4-6 hours.

Contraindications

• Hypersensitivity to pyrilamine or similar antihistamines.
• Use caution in patients with glaucoma, urinary retention, hypertension, or cardiovascular disease.

Precautions

• Use with caution in elderly, children, and those with central nervous system depression.

Adverse Reactions - Common

• Sedation, drowsiness (Common)
• Dry mouth, dizziness (Common)

Adverse Reactions - Serious

• CNS depression, respiratory depression (Rare)
• Allergic reactions including rash, urticaria (Rare)

Drug-Drug Interactions

• CNS depressants, alcohol, other sedatives

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed.
• Avoid activities requiring alertness until response is known.
• Do not consume alcohol or CNS depressants without consulting healthcare provider.
• Report excessive drowsiness, allergic reactions, or other side effects.

Special Considerations

Black Box Warnings:

• CNS depression, especially in elderly, young children, or if combined with other CNS depressants.

Genetic Factors: Not specifically linked to genetic testing.

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Severe drowsiness, hallucinations, seizures, respiratory depression.

Treatment: Supportive care, ensure airway patency, administer activated charcoal if within appropriate time frame, and provide symptomatic treatment.

Storage and Handling

Storage: Store at room temperature away from moisture, light, and heat.

Stability: Stable under proper storage conditions.