Data, obtained in clinical trials
Overview
The results of clinical studies have demonstrated that the use of cetirizine at recommended doses leads to the development of minor undesirable effects on the central nervous system (CNS), including drowsiness, fatigue, dizziness and headache. In some cases, a paradoxical stimulation of the central nervous system was registered.
Although cetirizine is a selective blocker of peripheral H1-receptors and almost no anticholinergic action, reported on single cases of difficulty urinating, accommodation and dry mouth disorders.
Reported violations of liver function, accompanied by increased levels of hepatic enzymes and bilirubin. In most cases, adverse events were resolved after cetirizine was discontinued.
The list of undesirable side reactions
There are data from double-blind, controlled clinical trials aimed at comparing cetirizine and placebo or other antihistamines used at the recommended doses (10 mg once daily for cetirizine) in more than 3,200 patients, on the basis of which a reliable analysis can be made safety data.
According to a combined analysis, in placebo-controlled studies with cetirizine at a dose of 10 mg, the following adverse reactions were observed with a frequency of 1.0% or higher
| Undesirable reactions (WHO terminology) | Cetirizine 10 mg (n = 3260) | Placebo (n = 3061) |
| General violations and violations at the site of introduction |
| Fatigability | 1,63% | 0,95% |
| Disturbances from the nervous system |
| Dizziness | 1,10% | 0,98% |
| Headache | 7,42 % | 8,07% |
| Infringements from gastrointestinal tract |
| Abdominal pain | 0,98 % | 1,08% |
| Dry mouth | 2,09 % | 0,82% |
| Nausea | 1,07% | 1,14% |
| Mental disturbance |
| Drowsiness | 9,63 % | 5,00 % |
| Disturbances from the respiratory system, chest and mediastinal organs |
| Pharyngitis | 1,29% | 1,34% |
Although the incidence of sleepiness in the cetirizine group was higher than that in the placebo group, in most cases this adverse event was mild or moderate in severity. In an objective evaluation conducted in other studies, it was confirmed that the use of cetirizine in the recommended daily dose in healthy young volunteers does not affect their daily activity.
Children
In placebo-controlled studies, the following adverse events were observed in children aged 6 months to 12 years at a frequency of 1% or more:
| Undesirable reactions (terminology WHO) | Cetirizine (n =1656) | Placebo (n =1294) |
| Disorders from the gastrointestinal tract |
| Diarrhea | 1,0% | 0,6% |
| Mental disturbance | | |
| Drowsiness | 1,8% | 1,4% |
| Disturbances from the respiratory system, organs of the thoracic cue and mediastinum |
| Rhinitis | 1,4% | 1,1% |
| General violations and violations at the site of introduction |
| Fatigability | 1,0% | 0,3% |
Experience of post-registration application
In addition to the adverse events identified in clinical trials and described above, the following adverse reactions were observed in the post-marketing use of the drug.
Adverse events are presented below in terms of organ system classes MedDRA and frequency of development, on the basis of data on the post-marketing use of the drug. The incidence of adverse events was determined as follows: Often (≥1/10); often (≥1/100, <1/10); infrequently (≥1/1000, <1/100); rarely (≥1/10000, <1/1000); rarely (<1 /10000), frequency unknown (due to insufficient data).
On the part of the blood and lymphatic system: rarely - thrombocytopenia.
From the immune system: rarely - hypersensitivity reactions; rarely - anaphylactic shock.
Metabolic and nutritional disorders: frequency unknown - increased appetite.
Disorders from the psyche: infrequently - Excitation; rarely - aggression, confusion, depression, hallucinations, sleep disturbance; rarely - tick; frequency unknown - suicidal ideation.
From the nervous system: infrequently - paresthesia; rarely - convulsions; rarely - perversion of taste, dyskinesia, dystonia, fainting, tremor; frequency unknown - memory impairment, including amnesia.
From the side of the organ of vision: rarely - violation of accommodation, blurred vision, nystagmus.
From the organs of hearing: frequency unknown - Vertigo.
From the digestive system: infrequently - diarrhea.
From the side of the cardiovascular system: rarely - tachycardia.
Hepatobiliary disorders: rarely - change in functional hepatic samples (increased activity of transaminase, alkaline phosphatase, gamma-glutamyltransferase and bilirubin).
From the skin side: infrequently rash, itching; rarely - hives; rarely - angioedema, persistent drug erythema.
From the urinary system: rarely - dysuria, enuresis; frequency unknown - retention of urine.
General disorders: infrequently - asthenia, malaise; rarely - peripheral edema.
Research: rarely - weight gain.
Notification of adverse reactions
Of great importance is the system of notification of suspected adverse reactions after registration of the drug.
This allows continuous monitoring of the drug benefit / risk ratio.