Chlorotrimeton: Uses, Mechanism of Action, Indications, Dosage, Side Effects and Interactions

It is an antihistamine belonging to the group of propylamines (alkylamines).


  • It is a medication for the relief of the common cold and allergies.
  • Treats and prevents symptoms related to sneezing, itching, runny nose, watery eyes, hives, and skin rashes.
  • It acts as a blocker of the effects of histamine on the body.
  • It is in the group of the most effective antihistamines.

The chemical formula of Clorotrimeton

  • C16H19N2Cl.
  • 3- (4-chlorophenyl) -N, N-dimethyl-3-pyridin-2-yl-propan-1amina.


Coated tablets containing: Chlorphenamine Maleate 4 mg.

Mechanism of action

Chlorine-Trimeton prevents the effect of histamine on the increase in vascular permeability, which produces symptoms such as sneezing, runny nose, and itchy eyes.

It crosses the blood-brain barrier and causes drowsiness due to the function of cerebral H1 receptors, involved in the control of sleep/wakefulness.

In addition, Chloro-Trimeton causes anticholinergic results, which provides a drying effect on the nasal mucous membranes.

Indications of Chlorotrimeton

Chloro-Trimeton or chlorphenamine maleate is indicated in the treatment of various allergies:

In treating perennial and seasonal allergic rhinitisallergic conjunctivitis, vasomotor rhinitis, allergic cutaneous manifestations, improvement of allergic reactions to plasma or blood, and angioedema.


It also has therapeutic indications for treating anaphylactic reactions in conjunction with epinephrine.

It relieves cutaneous skin conditions such as atopic dermatitis, allergic eczema, insect bites, contact dermatitis, drug reactions, and dermographism.


Chloro-Trimeton is administered orally, in individualized doses according to the patient’s needs and answers.

  • In adults and children over 12 years of age, give one tablet 3-4 times a day and do not exceed 24 mg daily.
  • In children of 6 – 12 years, give half a tablet 3 or 4 times a day and do not exceed 12 mg daily.
  • In children aged 2 to 6 years: supply a quarter of a tablet or 1 mg, 3 or 4 times a day, which is usually sufficient, without exceeding 4 mg daily; you should carefully calculate the use of this drug in the infants.

Side effects of Clorotrimeton

Common side effects:

Side effects caused by the use of Chloro-Trimeton include:

Anxiety, nervousness, diarrhea, constipation, upset stomach, vomiting, feeling weak, difficulty sleeping, nausea, loss of appetite, drowsiness, dryness of the throat, nose or mouth, headache, and excitability.

Serious side effects:

Some side effects that are more serious than can occur due to the use of Chlor-Trimeton.

These virtually harmful side effects are hallucinations, inability or difficulty urinating, seizures, severe dizziness, tremors, changes in vision, and irregular or rapid heartbeats.

Allergic reactions

Some patients may experience extreme allergic reactions to the antihistamine.

Some of the symptoms are hives, skin rashes, difficulty breathing, tightness in the chest, and inflammation.

Caution and contraindications of Chlorotrimeton

Special care must be taken when considering Chloro-Trimeton as a medicine.

  • If you have kidney disease, stomach ulcers, glaucoma, severe constipation, thyroid disorders, enlarged prostate, or difficulty urinating.
  • Chlorine Trimeton should not be administered in case of allergy to chlorpheniramine.
  • Chlorine-Trimeton has the effects of drowsiness and sedation and can reduce the ability of reflexes and concentration. The patient must be warned to avoid driving cars or dangerous heavy machinery under his effects.
  • Chloro-Trimeton can cross the placenta, so its use during pregnancy is not recommended; on the other hand, in breast milk, small amounts of antihistamine are passed. So there is a risk that adverse effects such as hyperexcitability will be caused in infants.
  • In children and the elderly can cause more marked side effects, so special attention should be paid when antihistamines are prescribed to these two age groups.
  • It is contraindicated in the case of hypersensitivity to the components or other antihistamines with a similar chemical structure.
  • In newborns or premature babies and children under three years of age.
  • In patients with monoamine oxidase inhibitor therapy.

The risk-benefit ratio should be evaluated in patients with narrow-angle glaucoma, prostatic hypertrophy, bladder neck obstruction, pyloroduodenal obstruction, stenosing peptic ulcer, and increased intraocular pressure.

As well as bronchial asthmahyperthyroidism, and cardiovascular diseases including hypertension.


An overdose of Chloro-Trimeton can bring potentially serious consequences; the effects of overdoses vary from central nervous system depression such as sedative effects, hyperreflexia, and diminished mental alertness.

It also generates seizures, apneacyanosis, and cardiovascular collapse, until stimulation, such as hallucinations, insomnia, tremors, or even death.

The stimulation symptoms and signs and symptoms are similar to those induced by atropine, such as dilated and fixed pupils, hyperthermia, dry mouth, flushing, and gastrointestinal disorders that usually occur in children.

Chlorotrimeton Interactions

Chloro-Trimeton interacts with alcohol, barbiturates, tricyclic antidepressants, and other depressants; antihistamines can inhibit the action of anticoagulants.

To carry out tests in the laboratory, antihistamines should be discontinued at least four days before performing the dermatological tests. Usually, these agents can prevent or diminish the manifestation of positive reactions to indicators.