Source: Medicines & Healthcare Products Regulatory Agency (GB) Revision Year: 2021 Publisher: GlaxoSmithKline Consumer Healthcare (UK) Trading Limited, 980 Great West Road, Brentford, Middlesex, TW8 9GS, UNITED KINGDOM
Piriton tablets are contra-indicated in patients who are hypersensitive to antihistamines or to any of the tablet ingredients.
The anticholinergic properties of chlorphenamine are intensified by monoamine oxidase inhibitors (MAOIs). Piriton Tablets is therefore contra-indicated in patients who have been treated with MAOIs within the last fourteen days.
Chlorphenamine, in common with other drugs having anticholinergic effects, should be used with caution in epilepsy; raised intra-ocular pressure including glaucoma; prostatic hypertrophy; severe hypertension or cardiovascular disease; bronchitis, bronchiectasis and asthma; hepatic impairment; renal impairment. Children and the elderly are more likely to experience the neurological anticholinergic effects and paradoxical excitation (eg. increased energy, restlessness, nervousness). Avoid use in elderly patients with confusion.
The anticholinergic properties of chlorphenamine may cause drowsiness, dizziness, blurred vision and psychomotor impairment in some patients which may seriously affect ability to drive and use machinery.
Concurrent use with drugs which cause sedation such as anxiolytics and hypnotics may cause an increase in sedative effects, therefore medical advice should be sought before taking chlorphenamine concurrently with these medicines.
The effects of alcohol may be increased and therefore concurrent use should be avoided.
Should not be used with other antihistamine containing products, including antihistamine containing cough and cold medicines.
Patients with rare hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine,
Keep out of sight and reach of children.
Concurrent use of chlorphenamine and hypnotics or anxiolytics may cause an increase in sedative effects, concurrent use of alcohol may have a similar effect therefore medical advice should be sought before taking chlorphenamine concurrently with these medicines.
Chlorphenamine inhibits phenytoin metabolism and can lead to phenytoin toxicity.
The anticholinergic effects of chlorphenamine are intensified by MAOIs (see Contra-indications).
There are no adequate data from the use of chlorphenamine maleate in pregnant women. The potential risk for humans is unknown. Use during the third trimester may result in reactions in the newborn or premature neonates. Not to be used during pregnancy unless considered essentially by a physician.
Chlorphenamine maleate and other antihistamine may inhibit lactation and may be secreted in breast milk. Not to be used during lactation unless considered essential by a physician.
The anticholinergic properties of chlorphenamine may cause drowsiness, dizziness, blurred vision and psychomotor impairment, which can seriously hamper the patients' ability to drive and use machinery.
The following convention has been utilised for the classification of the frequency of adverse reactions: very common (>1/10), common (>1/100 to <1/10), uncommon (>1/1000 to <1/100), rare (>1/10,000 to <1/1000) and very rare (<1/10,000), not known (cannot be estimated from available data).
Adverse reactions identified during post-marketing use with chlorphenamine are listed below. As these reactions are reported voluntarily from a population of uncertain size, the frequency of some reactions is unknown but likely to be rare or very rare:
System Organ Class | Adverse Reaction | Frequency |
---|---|---|
Nervous system disorders* | Sedation, somnolence | Very common |
Disturbance in attention, abnormal coordination, dizziness headache | Common | |
Eye disorders | Blurred Vision | Common |
Gastrointestinal disorders | Nausea, dry mouth | Common |
Vomiting, abdominal pain, diarrhoea, dyspepsia | Unknown | |
Immune system disorders | Allergic reaction, angioedema, anaphylactic reactions | Unknown |
Metabolism and nutritional disorders | Anorexia | Unknown |
Blood and lymphatic system disorders | Haemolytic anaemia, blood dyscrasias | Unknown |
Musculoskeletal and connective tissue disorders | Muscle twitching, muscle weakness | Unknown |
Psychiatric disorders | Confusion*, excitation*, irritability*, nightmares*, depression | Unknown |
Renal and urinary disorders | Urinary retention | Unknown |
Skin and subcutaneous disorders | Exfoliative dermatitis, rash, urticaria, photosensitivity | Unknown |
Respiratory, thoracic and mediastinal disorders | Thickening of bronchial secretions | Unknown |
Vascular disorders | Hypotension | Unknown |
Hepatobiliary disorders | Hepatitis, including jaundice | Unknown |
Ear and labyrinth disorders | Tinnitus | Unknown |
Cardiac disorders | Palpitations, tachycardia, arrythmias | Unknown |
General disorders and administration site conditions | Fatigue | Common |
Chest tightness | Unknown |
* Children and the elderly are more likely to experience the neurological anticholinergic effects and paradoxical excitation (eg. increased energy, restlessness, nervousness).
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at:www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
None reported.
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