Myths and legends

How long does it take for citrine to work?

Tablets: round, biconvex, covered with a film shell of white or almost white color, with a mark on one side. On a cross section, the core is white to almost white.

pharmachologic effect

pharmachologic effectH1-antihistamine, H1-antihistamine.


Competitive histamine antagonist, metabolite of hydroxyzine, blocks H1– histamine receptors. Prevents the development and facilitates the course of allergic reactions, has antipruritic and antiexudative effects. Affects the early stage of allergic reactions, limits the release of inflammatory mediators at the late stage of the allergic reaction, reduces the migration of eosinophils, neutrophils and basophils. Reduces capillary permeability, prevents the development of tissue edema, relieves spasm of smooth muscles. Eliminates skin reactions to the introduction of histamine, specific allergens, as well as to cooling (with cold urticaria). Reduces histamine-induced bronchoconstriction in mild bronchial asthma. It has virtually no anticholinergic and antiserotonin effects. In therapeutic doses it practically does not cause a sedative effect. The onset of the effect after a single dose of 10 mg of cetirizine is 20 minutes, lasts more than 24 hours. During a course of treatment, tolerance to the antihistamine effect of cetirizine does not develop. After stopping treatment, the effect lasts up to 3 days.


Rapidly absorbed from the gastrointestinal tract (GIT), time to reach maximum concentration (TCmax) after oral administration – about 1 hour. Food does not affect the completeness of absorption (AUC), but prolongs T by 1 hourCmax and reduces the maximum concentration ( CMax ) by 23%. When taken at a dose of 10 mg once a day for 1 days, the equilibrium concentration of the drug (Css ) in plasma is 310 ng/ml and is observed 0,5–1,5 hours after administration. Plasma protein binding is 93% and does not change with cetirizine concentrations in the range of 25–1000 ng/ml. The pharmacokinetic parameters of cetirizine change linearly when administered at a dose of 5–60 mg. Volume of distribution (Vd) – 0,5 l/kg. Metabolized in small quantities in the liver by O-dealkylation to form a pharmacologically inactive metabolite (unlike other H blockers1-histamine receptors metabolized in the liver with the participation of the cytochrome P450 system). Cetirizine does not accumulate. About 2/3 of the drug is excreted unchanged by the kidneys and about 10% in the feces. Systemic clearance – 53 ml/min. Half-life (T1/2 ) in adults – 10 hours, in children 6-12 years old – 6 hours, 2-6 years old – 5 hours, 0,5-2 years old – 3,1 hours. In elderly patients T1/2 increases by 50%, systemic clearance decreases by 40% (decreased renal function). In patients with impaired renal function (Cl creatinine below 40 ml/min), drug clearance decreases, and T1/2 lengthens (for example, in patients on hemodialysis, the total clearance decreases by 70% and amounts to 0,3 ml/min/kg, and T1/2 lengthens by 3 times), which requires a corresponding change in the dosage regimen. It is practically not removed during hemodialysis. In patients with chronic liver diseases (hepatocellular, cholestatic or biliary cirrhosis of the liver), there is an increase in T1/2 by 50% and a decrease in total clearance by 40% (correction of the dosage regimen is required only with a concomitant decrease in glomerular filtration rate (GF). Penetrates into breast milk.


  • seasonal and year-round allergic rhinitis;
  • allergic conjunctivitis;
  • hay fever (hay fever);
  • urticaria, incl. chronic idiopathic urticaria;
  • itchy allergic dermatoses (atopic dermatitis, neurodermatitis);
  • angioedema (Quincke’s edema).

According to the World Health Organization, 40% of the world’s population suffers from allergic diseases. Allergy is a chronic disease. Millions of people are forced to take medications regularly. The main ones are antihistamines. Doctors divide these drugs into three generations depending on their effect on the body.

Pharmacist Natalya Zotina talks about the second generation drug Cetrine: what its active ingredient is, what dosages are recommended for adults and children, whether it has contraindications and side effects. Compares Cetrin with its closest analogues.


Cetrin is produced by the Indian company Dr. Reddy’s Laboratories Ltd. It is produced in the form of tablets containing 10 mg of cetirizine dihydrochloride. The drug does not have any other dosage forms or dosages.

Active substance

The drug contains the active substance cetirizine. It blocks H1-histamine receptors, suppresses the release of mediators of allergic inflammation and stops the development of an allergic reaction.

Cetirizine is included in the Russian List of vital and essential drugs for medical use. Used for treatment since 1987.

Allergy drug

  • blocks the sensitivity of receptors to histamine, the main mediator of allergic inflammation
  • reduces capillary permeability
  • reduces swelling
  • relieves itching
  • relieves spasm of smooth muscles, including bronchi
  • eliminates skin reaction to cold

What does the medicine help with?

  • allergic rhinitis
  • allergic conjunctivitis
  • hay fever (hay fever)
  • hives
  • dermatoses accompanied by itching: neurodermatitis, atopic dermatitis
  • Quincke’s edema

Why is Cetrin prescribed?


  • with hypersensitivity to cetirizine and hydroxyzine
  • during pregnancy and lactation
  • if the child is under 6 years old


Cetrin tablets are taken whole, not chewed, and washed down with a glass of water. Eating does not affect the effect of the drug. Adults are prescribed Cetrin once a day, 10 mg. Or 5 mg twice a day, dividing the tablet in half.

Exceptions to admission for patients with kidney disease:

  • 5 mg per day for reduced renal function
  • 5 mg every other day for severe chronic renal failure

How long does it take for Cetrin to work?

Cetrin begins to act within 20 minutes after taking the tablet. The effect of one dose lasts for a day. When taken as a course after discontinuation of the drug, its effect lasts for three days.

Drug dosage for children

Cetrin tablets are approved for use by children over 6 years of age. The regimen is the same as for adults: once a day, 10 mg or twice a day, 5 mg (½ tablet).

How long can I take the drug?

The duration of treatment with Cetrin is determined by the doctor. On average, treatment time ranges from a week to a month. Usually the drug is discontinued after allergy symptoms disappear.

You may be interested in: Antiallergy drugs and inexpensive allergy pills

Side effects

  • dry mouth
  • headache, migraine, dizziness
  • abdominal pain, bloating, dyspepsia
  • allergic reactions: swelling, rash, itching

Overdose of Cetrin:

  • occurs with a single dose of 50 mg of the drug
  • manifested by dry mouth, drowsiness, constipation, urinary retention, irritability and restlessness
  • treated with gastric lavage and symptomatic remedies

The speed of reactions worsens when taking a dose of more than 10 mg per day.

Medicine and alcohol: compatibility

Cetrin does not interact with alcohol in recommended doses. However, the manufacturer’s instructions warn against drinking alcohol while taking the drug.


  • Zirtek
  • Zodak
  • Zintset
  • Parlazin
  • Solonex
  • Sensor
  • Cetirizine

Their contraindications and side effects are similar. Analogues differ in dosage forms. Thus, Zodak, Zyrtec and Cetirizine are produced in tablets and drops, and Zincet – in tablets and syrup. Parlazin, Solonex and Sensinor are presented in pharmacies only in drops for internal use.

These drugs are interchangeable, provided the dosage form for administration is followed. For children from 6 months of age, the doctor prescribes cetirizine in the form of drops. The medication is taken under medical supervision. Zincet syrup can be taken by children from 2 years of age.

Suprastin or Cetrin: which is better?

Suprastin is a first generation antihistamine. The active substance is chloropyramine. It differs from second generation drugs in that it acts not only on histamine receptors, but also on the central nervous system. Suprastin causes drowsiness, reduces reaction speed and enhances the effect of alcohol. It is prohibited to drink alcohol while taking Suprastin. It has many more side effects than Cetrin.

When taken orally, its effect begins within 15-30 minutes and lasts for 3-6 hours. Suprastin is produced in tablets and solution for intramuscular and intravenous administration. Tablets are approved for children from 3 years of age. The injection solution is used for acute manifestations of allergies from 1 month of life.

Suprastin and Cetrin tablets are sold from pharmacies without a prescription. The safety profile is higher for Cetrin.

Loratadine or Cetrin: which is better?

The active substance of drugs called Loratadine is the substance of the same name. It, like cetirizine, is a second generation antihistamine. The therapeutic effect of the analogues is similar, despite the difference in chemical structure.

The action of Loratadine begins half an hour after administration and lasts 24 hours, like Cetrin. According to the instructions, Loratadine is not used for allergic dermatitis and Quincke’s edema. Loratadine is available in the form of tablets and syrup, approved for children from 3 and 2 years of age, respectively.

Both drugs have proven effectiveness. Sold in pharmacies without a prescription. Loratadine is suitable for children under 6 years of age. To choose a drug, it is better for an adult patient to consult a doctor or pharmacist.

Zodak or Cetrin: which is better?

Zodak and Cetrin are direct analogues, both contain cetirizine. Zodak is made in Russia, Tsetrin is made in India.

Zodak has two dosage forms: oral drops and tablets. Drops are used to treat children from 6 months, but only as prescribed by a doctor and under his supervision.

Cetrin has a wider range of indications for use: it is prescribed for dermatoses that are accompanied by itching and Quincke’s edema. Zodak does not have such indications in the instructions.


  • The composition of the drug Cetrin includes the active substance cetirizine dihydrochloride. It blocks histamine receptors and stops the development of an allergic reaction.
  • Cetrin is used for various types of allergies: allergic rhinitis and conjunctivitis, hay fever, urticaria, dermatoses with itchy skin, Quincke’s edema.
  • Dosage for adults and children over 6 years of age: 5 mg twice daily or 10 mg once daily. The duration of treatment and dosage are prescribed by the doctor.
  • Cetrin may have side effects: dry mouth, headaches, dyspepsia and allergic reactions.
  • Treatment with Cetrin tablets is contraindicated in children under 6 years of age, pregnant and lactating women, and those with hypersensitivity to the components of the drug and hydroxyzine.
  • The manufacturer indicates in the instructions that it is undesirable to drink alcohol during treatment with Cetrin.
  • Cetrin analogues: Zirtec, Zintset, Zodak, Parlazin, Solonex, Sensinor, Cetirizine.
  • Suprastin is a first-generation antihistamine, and Cetrin, Zodak and Loratadine are second-generation. Second generation drugs have a higher safety profile and duration of action.

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