Cetirizine is a drug that has an antiallergic effect. The effect after use is achieved quickly and lasts for a long time. It is advisable to take it for prolonged allergic reactions, namely for year-round rhinitis and chronic urticaria.
Its distinctive feature is the ability to penetrate the skin, so the drug is used for eczema and allergic genesis.
Pharmacodynamics
The drug actively fights allergic manifestations, has an antipruritic and antiexudative effect. Capillaries become less permeable, muscle spasms and skin irritations disappear. Reduces excessive bronchial activity in patients suffering from asthma.
Practically does not lead to a sedative reaction. The result is achieved in 50-60 minutes, the maximum effect is observed after 4 hours and lasts for a day. After completion of the treatment course, the drug continues to act for another 72 hours. During the treatment process, addiction to the medicine does not occur.
Instructions for use
Drops
From the age of 12 years you can take 20 drops in the evening. A child from 6 to 12 years old can also be given 20 drops, preferably in the evening. Children from 2 to 6 years old - 10 drops in the evening, from 1 to 2 years old - 5 drops 2 times a day.
For older people, the dose is not adjusted. In case of renal failure, reduce the dosage by 2 times. For seasonal allergic rhinitis, the course of treatment averages 1-1.5 months. If the allergy is short-term – 7-10 days.
Pills
The tablets are taken in the evening. From 12 years old take 1 tablet per day. A child from 6 to 12 years old weighing more than 30 kg can be given 1 tablet per day. If you weigh less than 30 kg – half a tablet.
Cetirizine, drops
Dosage regimen
Adults and children over 12 years old
The recommended dose is 10 mg (24 drops) once daily.
Children 6-12 years old
The recommended dose is 5 mg (12 drops) twice daily.
Children 2-5 years old
The recommended dose is 2.5 mg (6 drops) twice daily.
Children from 1 year to 2 years
The recommended dose is 2.5 mg (6 drops) once or twice daily.
Children from 6 months to 1 year
The recommended dose is 2.5 mg (6 drops) once daily.
The maximum duration of treatment in children with seasonal rhinitis should not exceed 4 weeks.
Special patient groups
Elderly
According to available data, with normal renal function, age is not a reason to reduce the dose.
Patients with impaired renal function
There is no data confirming the effectiveness/safety of the drug in patients with impaired renal function. Since cetirizine is mainly excreted through the kidneys (see section “Pharmacokinetic properties”), if it is impossible to use alternative treatment, the dose of the drug should be selected individually, taking into account renal function. The table below helps you choose the right dose. To use this table, it is necessary to determine creatinine clearance (CC) in ml/min. To do this, it is necessary to determine the serum creatinine level and calculate CC using the following formula:
CC = [140 - age (in years)] x weight (kg) (x 0.85 for women)
72 x serum creatinine (mg/dL)
Dose adjustment in patients with impaired renal function:
| Group | CC (ml/min) | Dose and frequency of administration |
| Normal kidney function | >80 | 10 mg (24 drops) 1 time/day |
| Mild renal impairment | 50-79 | 10 mg (24 drops) 1 time/day |
| Moderate renal impairment | 30-49 | 5 mg (12 drops) 1 time/day |
| Severe renal impairment | 10-29 | 5 mg (12 drops) once every two days |
| End stage renal failure, dialysis | <10 | Contraindicated |
For children with impaired renal function, the dose should be selected individually, taking into account renal clearance, as well as the age and body weight of the patient.
Patients with impaired liver function
In patients with only liver dysfunction, there is no need for dose adjustment.
Patients with impaired liver and kidney function
Dose adjustment is recommended (see section “Patients with impaired renal function” above).
Mode of application
Drops for oral administration.
The use of the drug does not depend on food intake (see section “Pharmacokinetic properties”).
The solution should either be dripped into a spoon or diluted with water and taken orally. If the solution is diluted with water, then it should be taken into account that the volume of liquid used to dissolve the drug corresponds to the amount of liquid that the patient is able to drink. This is especially important when dosing the drug to children.
Side effects
After administration, the following negative reactions may occur:
- excited state;
- skin rashes;
- diarrhea;
- asthenia.
In rare cases it is possible:
- cardiopalmus;
- hepatitis;
- hives;
- dizziness (up to fainting);
- nervous system disorder;
- disturbed sleep;
- stress.
If you follow the instructions and do not exceed the dosage, then even with prolonged treatment the likelihood of adverse reactions is minimized.
Use during pregnancy
The instructions for the drug say that Cetirizine should not be taken while pregnant. This is due to the fact that no studies have been conducted on pregnant women. Animal studies have not shown any adverse reactions to the fetus. There is also no information on the effects of the drug during lactation, so you should avoid taking it during breastfeeding.
A few studies indicate that taking the drug in the 1st trimester has no effect on the number of congenital defects, the frequency of miscarriages and the premature birth of a baby. The weight of the newborn also did not differ from normal values.
If a pregnant woman experiences allergic reactions, then, taking into account the possible risks, it is better to give preference to Fencarol, cetirizine, which should be avoided in the first trimester.
Cetirizine
Data obtained from clinical studies
Review
The results of clinical studies have demonstrated that the use of cetirizine in recommended doses leads to the development of minor undesirable effects on the central nervous system, including drowsiness, fatigue, dizziness and headache. In some cases, paradoxical stimulation of the central nervous system has been reported.
Despite the fact that cetirizine is a selective blocker of peripheral H1 receptors and has virtually no anticholinergic effect, isolated cases of difficulty urinating, disturbances of accommodation and dry mouth have been reported.
Liver dysfunction has been reported, accompanied by increased liver enzymes and bilirubin levels. In most cases, adverse events resolved after discontinuation of cetirizine.
List of unwanted side effects
Data from double-blind, controlled clinical trials comparing cetirizine with placebo or other antihistamines given at recommended doses (10 mg once daily for cetirizine) in more than 3200 patients are available on which to conduct a reliable analysis safety data.
According to the results of the pooled analysis, in placebo-controlled studies with the use of cetirizine at a dose of 10 mg, the following adverse reactions were identified with a frequency of 1.0% or higher:
| Adverse reactions (WHO terminology) | Cetirizine (n=3260) | Placebo (n=3061) |
| General disorders and disorders at the injection site | ||
| Fatigue | 1,63 % | 0,95 % |
| Nervous system disorders | ||
| Dizziness | 1,10 % | 0,98 % |
| Headache | 7,42 % | 8,07 % |
| Gastrointestinal disorders | ||
| Abdominal pain | 0,98 % | 1,08 % |
| Dry mouth | 2,09 % | 0,82 % |
| Nausea | 1,07 % | 1,14 % |
| Mental disorders | ||
| Drowsiness | 9,63 % | 5,00 % |
| Respiratory, thoracic and mediastinal disorders | ||
| Pharyngitis | 1,29 % | 1,34% |
Although the incidence of somnolence in the cetirizine group was higher than that in the placebo group, most cases were mild or moderate in severity. When objectively assessed in other studies, it was confirmed that the use of cetirizine at the recommended daily dose in healthy young volunteers does not affect their daily activities.
Children
In placebo-controlled studies, the following adverse reactions were observed with an incidence of 1% or greater in children aged 6 months to 12 years:
| Adverse reactions (WHO terminology) | Cetirizine (n=1656) | Placebo (n=1294) |
| Gastrointestinal disorders | ||
| Diarrhea | 1,0 % | 0,6 % |
| Mental disorders | ||
| Drowsiness | 1,8 % | 1,4 % |
| Respiratory, thoracic and mediastinal disorders | ||
| Rhinitis | 1,4 % | 1,1 % |
| General disorders and disorders at the injection site | ||
| Fatigue | 1,0 % | 0,3 % |
Post-registration experience
In addition to the adverse events identified during clinical trials and described above, during post-registration use of the drug,
no unwanted reactions follow.
Adverse events are presented below by MedDRA organ system class and incidence, based on post-marketing data.
drug.
The incidence of adverse events was defined as follows: “uncommon” (≥ 1/1000, < 1/100); “rare” (≥ 1/10000, < 1/1000); “very rare” (< 1/10000): - frequency unknown” (cannot be estimated based on available data).
Blood and lymphatic system disorders: very rarely - thrombocytopenia.
Immune system disorders: rarely - hypersensitivity reactions; very rarely - anaphylactic shock.
Metabolic and nutritional disorders: frequency unknown - increased appetite.
Mental disorders: infrequently - agitation; rarely - aggression, confusion, depression, hallucinations; very rarely - tic; frequency unknown - suicidal ideation, sleep disturbances (including nightmares).
Nervous system disorders: uncommon - paresthesia; rarely - convulsions; very rarely - taste perversion, dyskinesia, dystonia, fainting, tremor; frequency unknown - memory impairment, including amnesia, deafness.
Visual disturbances: very rarely - disturbance of accommodation, blurred vision, nystagmus; frequency unknown - vasculitis.
Hearing and labyrinthine disorders: frequency unknown - vertigo.
Cardiovascular system disorders: rarely - tachycardia.
Gastrointestinal disorders: infrequently - diarrhea.
Disorders of the liver and bile ducts: rarely - liver failure with changes in liver function tests (increased activity of transaminases, alkaline phosphatase, gamma-glutamyltransferase and bilirubin); frequency unknown - hepatitis.
Disorders of the skin and subcutaneous tissues: infrequently - rash, itching; rarely urticaria; very rarely - angioedema, persistent drug erythema; frequency unknown - acute generalized exanthematous pustulosis.
Renal and urinary tract disorders: very rarely - dysuria, enuresis; frequency unknown - urinary retention.
Musculoskeletal and connective tissue disorders: frequency unknown - arthralgia.
General disorders: infrequently - asthenia, malaise; rarely - peripheral edema.
Impact on the results of laboratory and instrumental studies: rarely - increased body weight.
Description of selected adverse reactions: after discontinuation of cetirizine, cases of itching, including intense itching and/or urticaria, have been reported.
It is important to report the development of adverse reactions to ensure continuous monitoring of the benefit-risk ratio of the drug. If any of the side effects indicated in the instructions get worse, or you notice any other side effects not listed in the instructions, tell your doctor. Health care professionals report adverse drug reactions through national adverse event reporting systems.
special instructions
After taking the medicine, you should not drive a vehicle.
Interaction with Diazepam, Cimetidine and Azithromycin has not been established. Use with Theophylline leads to a decrease in drug clearance. Particular caution should be taken in parallel with medications that have a depressant effect on the central nervous system.
The product enhances the effect of alcohol, so you should avoid taking it. The medication must be taken 3 days before allergy testing.
You can buy it at a pharmacy without a doctor's prescription.
Store at room temperature. Shelf life – 36 months from the date of release.
Cetirizine
Description of selected adverse reactions:
Cases of pruritus, including intense itching and/or urticaria, have been reported following discontinuation of cetirizine.
If you experience the side effects listed in the instructions, or they get worse, or you notice any other side effects not listed in the instructions, tell your doctor.
Overdose
Symptoms observed after apparent drug overdose have affected the central nervous system or have been associated with a possible anticholinergic effect. Symptoms that occurred after taking at least five times the recommended daily dose included the following: confusion, diarrhea, fatigue, headache, malaise, mydriasis, itching, restlessness, sedation, somnolence, stupor, tachycardia, tremor, urinary retention.
Treatment:
There is no specific antidote.
In case of overdose, symptomatic or supportive treatment is recommended. Gastric lavage and/or activated charcoal may be effective if the overdose has occurred recently. Cetirizine is partially eliminated by dialysis.
Interaction with other drugs
Concomitant use with azithromycin, cimetidine, erythromycin, ketaconazole or pseudoephedrine does not affect the pharmacokinetic parameters of cetirizine.
No pharmacokinetic interactions were observed. in vitro test
, cetirizine does not affect the protein binding effect of warfarin. Concomitant use of azithromycin, erythromycin, ketoconazole, theophylline and pseudoephedrine did not reveal significant changes in clinical laboratory parameters, vital signs and ECG.
In a study of co-administration of theophylline (400 mg per day) and cetirizine (20 mg per day), a small but statistically significant increase in 24-hour AUC (area under the curve) was found by 19% for cetirizine and 11% for theophylline. In addition, maximum plasma levels increased to 7.7% and
6.4%, respectively, for cetirizine and theophylline. At the same time, the clearance of cetirizine decreased by -16%, and also by -10% in the case of theophylline, when cetirizine was taken by patients who had previously received treatment with theophylline. However, pretreatment with cetirizine did not significantly affect the pharmacokinetic parameters of theophylline.
