Chlorphenamine: Indications, Dosage, Presentations, Side Effects, Warnings, Precautions and Interactions

It is a medicine belonging to the group of medications called antihistamines.

This substance counteracts the effect of histamine, a chemical mediator released from specific cells during allergic reactions.

Chemical names: chlorpheniraminechlorpheniraminechlorphenilpyridamine, dieldrin, and chlorotrimeton.

What is this medicine indicated for?

Chlorphenamine is a medication called antihistamines. It can be supplied to adults and children six years and older. It is used to relieve symptoms caused by allergies, such as watery eyes, itchy eyes, sneezing, runny nose, rash, and irritation.

It is also used to treat itching caused by insect bites and other diseases such as chickenpox or measles.

Chlorphenamine works by blocking the effects of histamine, a substance released by cells that produce allergic symptoms in the body.

This medicine is available under different brand names or in other presentations. In addition, some forms of this medication can not be used against all the conditions mentioned in this article.


Your doctor may have suggested this medication to treat a condition not listed in this medication information article. If this is the case, do not stop using chlorpheniramine and discuss the situation with your doctor, asking the questions that cause you concern.

At the end of the treatment, discard it, and do not give it to anyone even if they have the same symptoms. This medicine can be harmful to people for whom it has not been prescribed.

How should this medication be used?


It should be used to treat the symptoms of allergic rhinitis; The usual dose for adults and children over 12 years is 4 mg every 4 to 6 hours.

The usual dose for adults and children 12 years and older is 12 mg every 12 hours for continuous release tablets. The maximum recommended dose for 24 hours is 24 mg.

To prevent seasonal allergic rhinitis, the recommended initial dose is 4 mg at bedtime, which can be increased to 8 mg 3 times a day, as needed, over two weeks.

For children 6 to 11 years of age, the usual recommended dose is 2 mg every 4 to 6 hours. The maximum recommended dose for a 24-hour period is 12 mg.

This medication is not recommended for children under six years unless the doctor indicates otherwise.

Elderly or older adults may require lower doses given their age condition.

Several factors can be considered to determine the dose a person needs: weight, health, and other medications that they are taking.

If the administration of this medication was indicated to you differently from the ones noted here, follow the instructions given by your doctor and then consult him.

You must use this medication exactly as your doctor or pharmacist has told you.

If you miss a dose, take the medication as soon as notice the omission and resume treatment as quickly as possible.

Avoid as far as possible the omissions, oversights, or excesses so that the product has effectiveness and there are no overdose problems.

To eliminate expired or unused medications, it is recommended not to dispose of them in wastewater or domestic waste. Ask how to do it the experts in medicine or pharmacist.

Presentations of chlorphenamine

  • Tablets
  • Extended-release tablets / modified-release tablets.
  • Oral drops
  • Oral suspension/syrup
  • Injectable solution.

Cases in which this medication is not recommended

Do not use this medicine in the following circumstances:

  • You are allergic to chlorpheniramine or any of the ingredients in the medication.
  • If that is the condition, it is suggested to take an inhibitor such as phenelzine, tranylcypromine, or moclobemide.
  • Always under supervision and medical indication. Never without her.
  • Chlorphenamine is not indicated as a treatment in newborns or premature infants.

What are the possible side effects of this medication?

When talking about side effects, there is a probability that not all patients have the same reactions or side effects mentioned here since they vary according to the particular conditions of each one.

If you experience side effects or are concerned, consult your doctor.

At least 1% of people taking this medication reported the following side effects. Many of these side effects usually go away on their own over time or can be resolved.

It is also possible that your pharmacist can advise you on what to do if these side effects occur:

  • Constipation .
  • Diarrhea.
  • Sexual difficulties
  • Abdominal pain.
  • Emission of difficult urine.
  • State of general weakness.
  • Dizziness
  • Sickness.
  • Loss of appetite
  • Dry mouth.
  • Dryness of the vagina.
  • Drowsiness.
  • Vomiting

Most of the side effects listed below do not happen very often; however, if they do appear, the problems could escalate if you do not receive medical attention.

Check with your doctor as soon as possible if you experience any of the following side effects:

  • Agitation or a state of nervousness.
  • Nightmares.
  • Confusion.
  • Difficulty to sleep.
  • Pain to urinary urination.
  • Bruising or unusual bleeding
  • Skin rash or urticaria .
  • Uncontrolled emotion.
  • Hallucinations (hear, see or perceive phenomena that do not exist).
  • Lack of coordination.
  • Vision problems (for example, blurred vision).

Stop taking the medication and seek immediate medical attention if there is an answer, such as seizures.

Some people may experience side effects other than those listed. Consult your doctor if you notice a symptom you are concerned about while using this medicine.

Warnings and precautions

Women should mention if they are pregnant or breastfeeding. These factors can influence how you should use this medicine, as the safety of the fetus has not been proven.

When there are problems of this nature, liver problems should inform to the doctor before being administered chlorphenamine. Failure to do the liver condition could aggravate.

Drowsiness or reduced alertness: This medication may cause drowsiness. Avoid driving or operating machinery or equipment until you have determined that you are not sleepy during the day and that your mental and physical abilities are not affected while taking this medication.

Medical conditions: If you have any of the following conditions, inform your doctor before the use of chlorpheniramine:

Pregnancy: Chlorphenamine should not be used during pregnancy unless the benefits outweigh the risks. If a pregnancy occurs while taking this medication, contact your doctor immediately.

Breast-feeding: This medicine is transmitted through breast milk but does not seem to cause any harmful or significant effects in breast-fed babies. Consult your doctor to see if you should continue breastfeeding.

Children: the safety and efficacy of this medication have not been established for children under six years of age.

Older people may experience more side effects (e.g., drowsiness, dry mouth, difficulty urinating) while using this medication. Older people should not use this medicine unless recommended by a doctor, pharmacist, or other health professional.

Can other agents interact with this medicine?

There may be an interaction between chlorphenamine and any of the following:

  • Alcohol.
  • Narcotic analgesics (e.g., codeine, morphine, oxycodone).
  • Tricyclic antidepressants (e.g., amitriptyline, nortriptyline, desipramine).
  • Barbiturates (eg, phenobarbital, pentobarbital).
  • Benzodiazepinas (p. ej., lorazepam, diazepam).
  • Clarithromycin .
  • Erythromycin .
  • MAO inhibitors (for example, tranylcypromine, phenelzine, moclobemide).
  • Ketoconazole
  • Medications that have anticholinergic effects (e.g., benztropine, diphenhydramine).
  • Neuroleptic drugs (e.g., haloperidol, risperidone ).
  • Phenytoin

If you are taking any of these medications, consult your doctor or pharmacist. In your case, your doctor may ask you to:

  • Stop taking one of the medications.
  • Replace one drug with another.
  • Change the way you take one or both drugs.
  • Do not change anything at all.

The interference of one medication with another does not always result in the interruption of one of them. Ask your doctor what to do in case of interactions with other medicines.

Other medications not included in the list above may interact with this medication. Tell your doctor about everything you are taking, prescription or over-the-counter and herbal remedies. Do not forget to mention the supplements that you are ingesting.

If you consume caffeine, alcohol, nicotine, or illegal drugs, you should tell your doctor, as these substances can affect the action of many medications.

Other warnings

Dizziness, sedation, confusion, and hypotension may be more frequent in geriatric patients who take antihistamines.

There may be anticholinergic side effects in older adults, such as dry mouth and urinary retention (primarily in men) of antihistamines.

If these side effects occur and continue or are severe, medications are likely to be stopped.

Store this medication at room temperature, away from light and moisture, and out of the reach of children.

Prolonged use of antihistamines can decrease or inhibit salivary flow, thus contributing to caries, periodontal disease, oral candidiasis, and malaise.