SUMMARY OF PRODUCT CHARACTERISTICS

1 NAME OF THE MEDICINAL PRODUCT

When sold as an antihistamine :

Histergan Tablets When sold as a sleep aid:

Paxidorm Tablets 25 mg Dreemon Tablets

Numark Night Time Sleep Aid Tablets NightAid

Aspar Sleep Aid 25 mg Tablets

2. QUALITATIVE AND QUANTITATIVE COMPOSITION

Diphenhydramine Hydrochloride BP 25mg

3 PHARMACEUTICAL FORM

Sugar coated tablet (Tablet)

4 CLINICAL PARTICULARS

4.1 Therapeutic indications

As an antihistamine: Treatment of allergic conditions e.g. hay fever, vasomotor rhinitis, stings, urticaria, angioneurotic oedema, drug sensitivity, contact dermatitis and photosensitivity.

As a sleep aid: As a short term hypnotic.

4.2. Posology and method of administration

As an antihistamine:

Adults and Children over 12 years: 1 or 2 tablets three or four times per day. In severe or chronic conditions this may be increased at the discretion of a doctor, but not to exceed 300mg in any 24 hour period.

Elderly

As for adults, use cautiously, reduce dose if required.

Not recommended for children under the age of 12.

As a sleep aid:

Adults: 1 or 2 tablets at bedtime, or after retiring when sleep is not readily achieved.

Children: Not recommended for children under the age of 16.

Elderly: As for adults, use cautiously, reduce dose if required.

4.3. Contra-indications

Known sensitivity to any of the ingredients and/or porphyria. When used as a sleep aid: Sedation of children under the age of 16 should only be under medical direction, consequently use as a sedative in this age group is contraindicated.

4.4. Special warnings and precautions for use

Avoid concurrent taking of alcohol.

Use with caution in prostatic hypertrophy, epilepsy, glaucoma and hepatic disease and CNS depression or hypotension in the elderly. Caution should be exercised in patients with urinary retention.

4.5. Interaction with other medicinal products and other forms of interaction

Diphenhydramine may potentiate hypnotics and anxiolytics. Diphenhydramine and beta-histamine are antagonistic.

4.6. Pregnancy and lactation

Safety in pregnancy and lactation has not been demonstrated.

4.7. Effects on ability to drive and use machines

May cause drowsiness. If affected do not drive or operate machinery.

4.8. Undesirable effects

Dryness of mouth, dizziness, nausea, difficulty in micturation, allergic reaction and rarely thrombocytopenia. Headache, psychomotor impairment, blurred vision, gastrointestinal disturbances, palpitations, arrhythmias, hypotension, hypersensitivity (including bronchospasm, angioedma and anaphylaxis), rashes, photosensitivity, extrapyramidal effects, confusion, depression, sleep disturbances, tremor, convulsions, sweating, myalgia, paraesthesia, blood disorders, liver dysfunction, and hair loss.

4.9. Overdose

Symptoms: Dizziness, hypotension, inco-ordination, nausea, diarrhoea, vomiting, dryness of mouth, difficulty in micturation and convulsions. CNS stimulation (Paradoxical) and hyperpyrexia in children.

Treatment: Gastric lavage in the conscious patient (emetics should not be given) and intensive symptomatic supportive therapy where necessary. External cooling and I.V. fluids may be required in children. Anticonvulsive therapy may be necessary.

5    PHARMACOLOGICAL PROPERTIES

5.1    Pharmacodynamic properties

Diphenhydramine has anti-histaminic, anti-cholinergic (anti-spasmodic), antitussive and sedative activity.

5.2. Pharmacokinetic properties

Diphenhydramine is a histamine H₁ receptor antagonist.

The main site of metabolism is the liver.

Peak plasma concentration is in about 3 hours after ingestion.

The first hepatic pass will remove about 50% of an oral dose before reaching the general circulation.

Oral availability is about 50%.

5.3. Preclinical safety data

Not applicable.

6.1 List of excipients

Lactose, Corn Starch, Kollidon 25, Magnesium Stearate, Opaseal, Sucrose, Calcium Carbonate, Talc, Acacia, Titanium Dioxide, Opalux pink AS 1537, Opagloss, Silicone Fluid 200/350 cs

6.2. Incompatibilities

Incompatible with barbiturates and iodo compounds in solution.

6.3. Shelf life

36 months.

6.4.    Special precautions for storage

Store between 4°C and 25°C.

6.5.    Nature and contents of container

Blister packs of 8, 16 and 20 tablets.

Instructions for use/handling

Not applicable

7    MARKETING AUTHORISATION HOLDER

Norma Chemicals Ltd.

51-53 Stert Street Abingdon

Oxfordshire OX14 3JF United Kingdom

8.    MARKETING AUTHORISATION NUMBER

PL 00386/5008R

9.    DATE OF FIRST AUTHORISATION/RENEWAL OF AUTHORISATION

8 September 1989, 14 June 1995

10 DATE OF REVISION OF THE TEXT

04/07/2011