New Zealand - English - Medsafe (Medicines Safety Authority)
New Zealand Datasheet
1 PRODUCT NAME
DOZILE 25 mg capsules
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Doxylamine Succinate 25 mg Capsules
3 PHARMACEUTICAL FORM
Liquid filled soft gel capsules, purple, containing 25 mg doxylamine succinate.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Temporary use in the relief of insomnia.
4.2 Dose and method of administration
Adults: 1 capsule 30 minutes before retiring, or as directed by a pharmacist or physician.
Maximum stated dose should not be exceeded.
Dozile is recommended for occasional use only i.e. for periods of no longer than a week at a
time. If sleeplessness persists, consult your doctor.
Note: Dozile is not recommended for children under 12 years of age.
Hypersensitivity to doxylamine, other ethanolamine derivative antihistamines or to any other
ingredient in the product.
4.4 Special warnings and precautions for use
Caution should be used if taken with alcohol. Due to the anticholinergic properties of
used when Dozile is
medications. (See section 4.5)
Caution should be taken by those with narrow angle or open-angle glaucoma, urinary
Doxylamine may suppress positive skin test results.
Use in Children
Dozile is not recommended for children under 12 years of age. The safety and efficacy of
doxylamine as a night time sleep aid in children younger than 12 years of age have not been
established. In addition, children may be more prone than adults to experience paradoxical
CNS stimulation rather than sedation when antihistamines are used as night time sleep aids.
Use in the Elderly
The elderly may be more sensitive to the effects of the usual adult dose.
4.5 Interaction with other medicines and other forms of interaction
Dozile produces an additive effect when administered with other CNS depressants such as
opioid analgesics, neuroleptics, alcohol, hypnotics and psychotherapeutic drugs.
MAOIs may enhance the antimuscarinic effects of doxylamine.
Doxylamine has additive antimuscarinic action with other antimuscarinic drugs such as
atropine and tricyclic antidepressants.
Dozile may decrease the emetic response to apomorphine.
Concurrent use of oral contraceptives does not appear to affect the pharmacokinetics of
4.6 Fertility, pregnancy and lactation
childbearing age without any proven increase in the frequency of malformations or other
direct or indirect harmful effects on the fetus having been observed. Use of Dozile should be
avoided during pregnancy.
Use of Dozile should be avoided during lactation. First generation antihistamines may inhibit
lactation because of their anticholinergic actions. Small amounts of antihistamines are
distributed in human breast milk. Use is not recommended in nursing mothers because of
the risk of adverse effects, such as unusual excitement or irritability in infants.
Because of the potential for serious adverse reactions to antihistamines in nursing infants, a
decision should be made as to whether to discontinue nursing or doxylamine taking into
account the importance of the drug to the woman.
No data available.
4.7 Effects on ability to drive and use machines
Doxylamine causes drowsiness. Patients should not drive or operate machinery if affected.
4.8 Undesirable effects
CNS: CNS depression, stimulation (insomnia, nervousness, euphoria, irritability, tremors,
Respiratory: Thickened respiratory tract secretions.
Local: Dry mouth.
Cardiovascular: Palpitations, arrhythmias.
Ophthalmic: Blurred vision.
Renal: Urinary difficulty or retention.
Other: Hypersensitivity reactions, blood disorders, hypotension, tinnitus and paraesthesia.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicine is important. It
monitoring of the
Overdose produces signs and symptoms of anticholinergic toxicity. Acute overdose may
gastrointestinal symptoms, insomnia, nervousness, euphoria, irritability, tremors, nightmares,
tachycardia, mydriasis and a psychosis similar to that in catatonic stupor. Rhabdomyolysis
with impairment of renal function and acute renal failure has been observed. However, in
one series of cases of overdose, 39% of patients studied had no symptoms. Stimulation is
particularly likely in children.
Fatalities have been reported from doxylamine overdose. These have been characterized by
coma, grand mal seizures and cardiorespiratory arrest. Children appear to be at a high risk
for cardiorespiratory arrest. A toxic dose for children of more than 1.8 mg/kg has been
reported. A 3 year old child died 18 hours after ingesting 1,000 mg doxylamine succinate.
There is no correlation between the amount of doxylamine ingested, the doxylamine plasma
level and clinical symptomatology.
As overdosage may produce potentially fatal cardiovascular or CNS reactions, patients
should be monitored for any abnormalities of vital signs. Adequacy of ventilation and blood
pressure should be assessed and full supportive care, including oxygen and assisted
rhabdomyolysis. Laboratory tests on admission should include a determination of creatine
kinase. If this is elevated, a test for myoglobin in the urine should be done and, if present, is
a contraindication to acid diuresis. Adequate fluid replacement must be provided and good
urine output maintained.
Most patients recover with symptomatic and supportive care. Gastric lavage should be
considered if it can be performed soon after ingestion, generally within 60 minutes. Another
method of preventing absorption is charcoal administration, which again is most effective
when administered within 60 minutes of ingestion. Whole bowel irrigation with polyethylene
electrolyte lavage solution may
treatment of doxylamine overdose but are unlikely to be effective in view of the high volume
of distribution. The efficacy of forced diuresis has not been established.
suggested. For information on the management of overdose, contact the National Poisons
Centre on 0800 764 766.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Doxylamine succinate is a white or creamy white powder with a characteristic odour and has
solubilities of approximately 1 g/mL in water and 500 mg/mL in alcohol at 25°C. It has a pKa
of 5.8 and 9.3. A 1% aqueous solution has a pH of 4.8 - 5.2.
Doxylamine succinate is an ethanolamine derivative antihistamine. Because of its sedative
effect, it is used for the temporary relief of sleeplessness. The drug is also used in
combination with antitussives and decongestants for the temporary relief of cold and cough
symptoms. It is not structurally related to the cyclic antidepressants.
It is an antihistamine with hypnotic, anticholinergic, antimuscarinic and local anaesthetic
Duration of action is 6-8 hours.
5.2 Pharmacokinetic properties
Following oral administration of a single 25 mg dose of doxylamine succinate in healthy
adults, mean peak plasma concentrations of about 100 ng/mL occur within 2-3 hours after
administration. The drug has an elimination half-life of about 10 hours in healthy adults.
It is easily absorbed from the gastrointestinal tract. Following an oral dose of 25 mg the
mean peak plasma level is 99 ng/mL 2.4 hours after ingestion. This level declines to 28
ng/mL at 24 hours and 10 ng/mL at 36 hours.
The apparent volume of distribution is 2.5 L/kg.
acetylation, N-desalkylation and ether cleavage.
The elimination half life is 10.1 hours. Oral plasma clearance is 217 mL/min the drug is
excreted in the urine as unchanged doxylamine (60%), nordoxylamine and dinordoxylamine.
5.3 Preclinical safety data
No data available.
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
The capsules also contain the following inactive ingredients: butylated hydroxyanisole,
propylene glycol, macrogol 400, gelatin, amaranth, patent blue V, sorbitol special - glycerin
blend, and purified water.
None are known.
6.3 Shelf life
2 years (24 months).
6.4 Special precautions for storage
Store at or below 25°C.
6.5 Nature and contents of container
Dozile is available in a blister pack of 10 capsules.
7 MEDICINE SCHEDULE
Wilson Consumer Products
Ph: 09 379 5390
Fax: 09 379 5356
9 DATE OF FIRST APPROVAL
27 March 1997
10 DATE OF REVISION OF THE TEXT
13 May 2019
SUMMARY TABLE OF CHANGES
Summary of new information
Update to SPC format
Reporting of adverse events added
Poison centre details added