Chlorpheniramine

Chlorpheniramine is an antihistamine used to treat sneezing, itching, watery eyes, and runny nose caused by allergies or the common cold.

Chlorpheniramine is available under the following different brand names: ChlorTrimeton, and Diabetic Tussin.

Dosages of Chlorpheniramine:

Adult and Pediatric Dosage Forms and Strengths

Tablet

• 4 mg
• 8 mg
• 12 mg

Syrup

• 2 mcg/5 mL

The suspension (pediatric only)

• 2 mg/mL

Dosage Considerations – Should be Given as Follows:

Allergic Rhinitis

Adult:

• Tablets or syrup: 4 mg orally every 4-6 hours; not to exceed 24 mg/day
• Extended-release tablets: 8 mg orally every 8-12 hours or 12 mg every 12 hours; not to exceed 24 mg/day
• Extended-release capsules: 12 mg orally once/day; not to exceed 24 mg/day
• Sustained-release capsules: 8-12 mg orally every 8-12 hours, up to 16-24 mg/day

Pediatric:

• Children under 2 years: Safety and efficacy not established
• Children 2-6 years: 1 mg orally every 4-6 hours; not to exceed 6 mg/day
• Children 6-12 years: 2 mg orally every 4-6 hours; not to exceed 12 mg/day or sustained release at bedtime
• Children over 12 years:
  • Tablets or syrup: 4 mg orally every 4-6 hours; not to exceed 24 mg/day
  • Extended-release tablets: 8 mg orally every 8-12 hours or 12 mg every 12 hours; not to exceed 24 mg/day
  • Extended-release capsules: 12 mg orally once/day; not to exceed 24 mg/day
  • Sustained-release capsules: 8-12 mg orally every 8-12 hours, up to 16-24 mg/day

Geriatric:

• 4 mg orally once/day or every 12 hours
• Sustained-release: 8 mg orally at bedtime
• Non-anticholinergic antihistamines should be considered first when treating allergic reactions (Beers Criteria)
• Avoid use in the elderly because of the high incidence of anticholinergic effects
• Clearance reduced with advanced age, greater risk of confusion, dry mouth, constipation, and other anticholinergic effects and toxicity
• May exacerbate existing lower urinary conditions or benign prostatic hyperplasia

Additional Information

• See also combo with hydrocodone (Tussionex)

Other Indications and Uses

• Perennial and seasonal allergic and vasomotor rhinitis, relief of symptoms from colds, hives, angioedema, anaphylactic reactions, itching, allergic conjunctivitis

Common side effects of chlorpheniramine include:

• Abnormal/involuntary facial movements
• Acute labyrinthitis
• Agranulocytosis
• Blurred vision
• Central nervous system (CNS) depression
• Chills
• Cholestasis
• Constipation
• Delirium
• Diarrhea
• Disturbed coordination
• Dizziness
• Dizziness, sedation, and hypotension may occur in geriatric patients
• Double vision
• Drowsiness
• Dryness of mouth, nose, and throat
• Early menses
• ECG changes (e.g., widened QRS)
• Euphoria
• Faintness
• Fast heart rate
• Headache
• Hemolytic anemia
• Hepatitis
• High blood pressure (hypertension)
• Impotence
• Insomnia
• Irregular heartbeats (e.g., extrasystole, heart block)
• Irritability
• Lack of energy
• Liver failure
• Liver function abnormality
• Loss of appetite
• Low blood pressure (hypotension)
• Low platelet count (thrombocytopenia)
• Low red blood cell, white blood cell, and platelet count (pancytopenia)
• Low white blood cell count (leukopenia)
• Muscular weakness
• Nasal stuffiness
• Nausea
• Nervousness
• Numbness and tingling
• Pain or discomfort when urinating
• Palpitations
• Problems with memory or concentration
• Restlessness or excitability (especially in children)
• Ringing in the ears (tinn69tus)
• Sedation ranging from mild drowsiness to deep sleep (most frequent)
• Seizures (less common)
• Spinning sensation (vertigo)
• Stomach upset or pain
• Sweating
• Thickening of bronchial secretions
• Tightness of the chest
• Toxic psychosis
• Tremors
• Urinary retention
• Visual disturbances
• Vomiting
• Wheezing
• Yellowing skin and eyes (jaundice) (rare)

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

Chlorpheniramine has no known severe interactions with other drugs.

Serious interactions of chlorpheniramine include:

• eluxadoline
• idelalisib
• isocarboxazid
• ivacaftor
• sodium oxybate
• tranylcypromine

Chlorpheniramine has moderate interactions with at least 201 different drugs.

Mild interactions of chlorpheniramine include:

• ashwagandha
• brimonidine
• eucalyptus
• nettle
• sage
• Siberian ginseng

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

Warnings

This medication contains chlorpheniramine. Do not take ChlorTrimeton or Diabetic Tussin if you are allergic to chlorpheniramine or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• Documented hypersensitivity
• Lower respiratory disease, e.g., asthma (controversial)
• Preemies and neonates
• Nursing women
• Acute asthma, sleep apnea

Effects of Drug Abuse

• None

Short-Term Effects

• See "What Are Side Effects Associated with Using Chlorpheniramine?"

Long-Term Effects

• See "What Are Side Effects Associated with Using Chlorpheniramine?"

Cautions

• Caution in narrow-angle glaucoma, prostatic hypertrophy, stenosing peptic ulcer, pyloroduodenal obstruction, or bladder neck obstruction.
• Chlor-Trimeton non-drowsy contains no chlorpheniramine, only pseudoephedrine.
• All injections are discontinued.

Pregnancy and Lactation

• Use chlorpheniramine with caution during pregnancy if the benefits outweigh the risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.
• Chlorpheniramine's excretion in milk is unknown. It is not recommended for use while breastfeeding.