Consumer medicine information

Dimetapp PSE Cough Cold & Flu Night Relief Liquid Caps

Paracetamol; Pseudoephedrine hydrochloride; Dextromethorphan hydrobromide monohydrate; Doxylamine succinate

BRAND INFORMATION

Brand name

Dimetapp PSE Cough, Cold & Flu Night Relief

Active ingredient

Paracetamol; Pseudoephedrine hydrochloride; Dextromethorphan hydrobromide monohydrate; Doxylamine succinate

Schedule

S3

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Dimetapp PSE Cough Cold & Flu Night Relief Liquid Caps.

What is in this leaflet?

This leaflet answers some common questions about Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps. It does not contain all the available information.

It does not take the place of talking to your doctor or pharmacist.

Keep this leaflet with the medicine. You may need to read it again.

What is Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps used for?

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps have been developed specifically for adults and children 12 years of age and over.

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps combine the decongestant action of Pseudoephedrine with the antitussive action of the non-narcotic, centrally acting cough suppressant Dextromethorphan, the analgesic and antipyretic actions of Paracetamol, and the antihistaminic action of Doxylamine.

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps temporarily relieve the symptoms of the common cold & flu: minor aches, pains, headache, muscular aches, sore throat and fever. It also relieves dry irritating coughs due to minor throat and bronchial irritation, nasal and sinus congestion, runny nose, sneezing, itchy, and watery eyes and sinus pain.

Before you take Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps

When you must not take it

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps if you have an allergy to:

  • any medicine containing paracetamol, dextromethorphan, pseudoephedrine and doxylamine succinate
  • any of the ingredients listed at the end of this leaflet.

Some of the symptoms of an allergic reaction may include:

  • shortness of breath
  • wheezing or difficulty breathing
  • swelling of the face, lips tongue or other parts of the body
  • rash, itching or hives on the skin.

Do not take this medicine if you are having an asthma attack.

Do not take this medicine if you:

  • have very high blood pressure
  • have severe coronary artery disease (heart disease caused by poor blood flow or narrowing of the blood vessels of the heart)
  • are taking prescription medication for depression, psychiatric or emotional conditions e.g. a monoamine oxidase inhibitor (MAOI), selective serotonin reuptake inhibitor (SSRI) or for Parkinson's disease, or for 2 weeks after stopping the medication. If you are unsure if your prescription medication contains any of these drugs, ask a doctor or pharmacist before taking this product.

Do not take this medicine if you are pregnant or plan to become pregnant. It may affect your developing baby if you take it during pregnancy. Your pharmacist or doctor will discuss the benefits and possible risks of taking the medicine during pregnancy.

Do not take this medicine if you are breastfeeding or plan to breastfeed. It passes into the breast milk and there is a possibility that the baby may be affected.

Do not use this product in children under 12 years of age.

Do not take this medicine after the expiry date printed on the pack or if the packaging is torn or shows signs of tampering. If it has expired or is damaged, return it to your pharmacist for disposal.

If you are not sure whether you should start taking this medicine, talk to your pharmacist or doctor.

Before you start to take it

Tell your pharmacist or doctor if you have allergies to any other medicines, foods, preservatives or dyes.

Tell your pharmacist or doctor if you have or have had any of the following medical conditions:

  • asthma
  • chronic obstructive airways disease
  • pneumonia
  • any other respiratory (breathing) conditions
  • liver or kidney disease
  • high blood pressure
  • overactive thyroid gland
  • diabetes
  • heart disease and poor blood flow in the blood vessels of the heart
  • glaucoma
  • prostate problems
  • stomach or duodenal ulcer, or other stomach problems
  • bladder problems
  • epilepsy

Tell your pharmacist or doctor if you have a chronic cough. This medicine may make your cough worse.

Tell your pharmacist or doctor if you have a condition that produces large amounts mucus. This medicine may make your condition worse.

If you have not told your pharmacist or doctor about any of the above, tell him/her before you start taking Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps.

Taking other medicines

Tell your pharmacist or doctor if you are taking any other medicines, including any that you get without a prescription from your pharmacy, supermarket or health food shop.

Some medicines and Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps may interfere with each other.

These include:

  • medicines used to treat depression, psychiatric or emotional conditions e.g. selective serotonin reuptake inhibitor (SSRI) or for Parkinson's disease
  • monoamine oxidase inhibitors, a medicine used to treat depression, especially if taken within the last 14 days
  • quinidine and amiodarone, medicines used to treat abnormal or irregular heart beat
  • opioid analgesics used to treat pain
  • medicines used to help you relax, sleep or relieve anxiety, such as sedatives
  • alcohol
  • Warfarin
  • metoclopramide, a medicine used to control nausea and vomiting
  • medicines used to treat epilepsy or fits
  • chloramphenicol, an antibiotic used to treat ear and eye infections
  • medicines used to treat heart conditions, high blood pressure
  • medicines used to treat urinary tract infections and bladder problems
  • medicines used to treat behavioural disorders
  • phenylephrine, a medicine used to treat congestion
  • appetite suppressants
  • cholestyramine (Questran, Questran Lite)

These medicines may be affected by Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps or may affect how well it works. You may need different amounts of your medicines, or you may need to take different medicines.

Your doctor and pharmacist will have more information on medicines to be careful with or avoid while taking this medicine.

How to use Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps

How much to use

For adults and children 12 years & over: Take 2 capsules orally with water at bedtime.

Do not exceed 2 capsules in 24 hours.

Do not exceed the recommended dosage.

Do not give Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps in children under 12 years of age.

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps should not be used for more than few days at a time except on medical advice.

A persistent cough may be a sign of a serious condition. If symptoms do not improve within 7 days (or within 48 hours in the case of children), tend to recur, or are accompanied by rash, persistent headache, fever that lasts more than 3 days, or if new symptoms occur, patients should consult a doctor.

If you forget to take it

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps should be taken only when it is necessary.

Do not use a double dose of this product to make up for the dose that you missed. This may increase the chance of you getting an unwanted side effect.

If you use too much (overdose)

Stop use and immediately telephone your doctor or Poisons Information Centre (telephone 13 11 26) or go to the nearest hospital straight away, if you think that you or anyone else may have used too much Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps. Do this even if there are no signs of discomfort or poisoning. Keep this telephone number handy.

While you are using Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps

Things you must do:

If anyone in the family becomes pregnant and happens to use Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps, tell your doctor or pharmacist immediately.

If you are about to be started on any new medicine tell your doctor, dentist or pharmacist that you are using Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps.

Things you must not do:

Adults:

Do not take this product for more than few days at a time unless your doctor tells you to.

Children:

Do not take this product for more than 48 hours unless your doctor tells you to.

Things to be careful of:

Do not drive or operate machinery until you know how this product affects you. This product may cause drowsiness and/or dizziness in some people and therefore may affect alertness. If this happens, do not drive or operate machinery.

Doxylamine succinate may cause drowsiness in some people.

Alcohol warning: If you generally consume 3 or more alcohol containing drinks per day, you should consult your doctor for advice on when and how you should take this product or any other paracetamol containing product.

Side Effects

Tell your doctor or pharmacist as soon as possible if you do not feel well whilst using Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps.

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps may have unwanted side effects in a few individuals. All medicines can have side effects. Ask for the advice of your doctor or pharmacist if you have any concerns about the effects of using this medicine.

Tell your doctor or pharmacist if you notice any of the following side effects and they worry you:

  • nervousness
  • shaking (tremor)
  • spinning sensation (vertigo)
  • headache
  • faster heart rate (tachycardia)
  • high blood pressure (hypertension)
  • drowsiness
  • dizziness
  • sleeplessness (insomnia)
  • nausea (feeling sick)
  • vomiting
  • dryness of the mouth
  • blurred vision
  • rash (including urticaria)

The above list includes the more common side effects of your medicine. They are usually mild.

If any of the following happen, tell your doctor immediately or go to Accident and Emergency at your nearest hospital:

  • excitation
  • extreme confusion
  • nervousness and anxiety
  • irritability
  • rectal bleeding
  • restlessness
  • severe nausea and vomiting
  • shortness of breath, wheezing or difficulty breathing
  • sudden abdominal pain
  • swelling of the face, lips, tongue or other parts of the body
  • skin rashes, itching or hives on the skin
  • urine retention
  • severe skin reactions including skin reddening, blisters or rash

The above list includes serious side effects that may require medical attention. These side effects are rare.

Tell your pharmacist or doctor if you notice anything that is making you feel unwell.

Other side effects not listed above may also occur in some people.

After using Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps

Storage

Keep Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps in a cool dry place where the temperature stays below 25°C.

Do not leave it in the car or on window sills. Heat and dampness can destroy some medicines.

Keep it where children cannot reach it.

Disposal

After the expiry date has passed, any unused Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps should be returned to your pharmacist so that it can be disposed of safely.

Product description

What it looks like

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Cap is an oval, clear blue, soft gelatin capsule

Ingredients

Each Liquid capsule contains:

Dextromethorphan hydrobromide, 10mg

Pseudoephedrine hydrochloride, 30mg

Paracetamol, 300mg

Doxylamine Succinate, 6.25mg

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps also contain the following inactive ingredients:

  • Macrogol 400
  • Propylene glycol
  • Povidone
  • Gelatin
  • Glycerol
  • Sorbitol
  • Brilliant blue FCF CI42090
  • Water - purified

SUGAR FREE GELATIN CAPSULES.

Name and Address

For all enquiries please contact:

Pfizer Australia Pty Limited
Level 17, 151 Clarence Street,
Sydney, New South Wales, 2000
AUSTRALIA

Australia 1800 555 057
or visit: www.dimetapp.com.au

Dimetapp PSE Cough, Cold & Flu Night Relief Liquid Caps - AUST R 58353

Date of Preparation:
08 September 2005

Date of Revision: 17 June 2019.

Published by MIMS September 2019

BRAND INFORMATION

Brand name

Dimetapp PSE Cough, Cold & Flu Night Relief

Active ingredient

Paracetamol; Pseudoephedrine hydrochloride; Dextromethorphan hydrobromide monohydrate; Doxylamine succinate

Schedule

S3

 

1 Name of Medicine

Paracetamol, pseudoephedrine hydrochloride, dextromethorphan hydrobromide monohydrate and doxylamine succinate.

2 Qualitative and Quantitative Composition

Each liquid capsule contains paracetamol 300 mg, pseudoephedrine hydrochloride 30 mg, dextromethorphan hydrobromide monohydrate 10 mg and doxylamine succinate 6.25 mg.
Also contains: Sulfites and soya bean products.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Dimetapp PSE Cough, Cold & Flu Night Relief are soft gelatin capsules containing clear blue liquid.

4 Clinical Particulars

4.1 Therapeutic Indications

Dimetapp PSE Cough, Cold & Flu Night Relief temporarily relieve the following symptoms of the common cold and flu: minor aches, pains, headache, muscular aches, sore throat and fever associated with a cold or flu, irritating coughs due to minor throat and bronchial irritation, runny nose, sneezing, itchy and watery eyes, nasal and sinus congestion, and sinus pain.

4.2 Dose and Method of Administration

Dosage.

Adults and children 12 years and over.

Take 2 blue capsules orally with water at bedtime.
Do not exceed 2 blue night liquid capsules in 24 hours.
Do not use in children under 12 years.
Adults should not take this product for more than a few days at a time except on medical advice.
Children should not use this product for more than 48 hours, except on medical advice.

4.3 Contraindications

Dimetapp PSE Cough, Cold & Flu Night Relief are contraindicated for use in patients:
with known hypersensitivity to the active ingredients paracetamol, pseudoephedrine, dextromethorphan hydrobromide or doxylamine succinate or substances of similar chemical structure or any other ingredient in the product;
taking prescription medication for depression, psychiatric or emotional conditions e.g. a monoamine oxidase inhibitor (MAOI), selective serotonin reuptake inhibitor (SSRI) or for Parkinson's disease, or for 2 weeks after stopping the medication;
with severe hypertension or coronary artery disease;
with narrow-angle glaucoma;
with stenosing peptic ulcer;
with symptomatic prostatic hypertrophy;
with bladder neck obstruction;
with pyloroduodenal obstruction;
taking other antihistamines.
Dimetapp PSE Cough, Cold & Flu Night Relief should not be used during an acute asthma attack.
Dimetapp PSE Cough, Cold & Flu Night Relief are contraindicated for use in: children under 12 years of age; lactating women.

4.4 Special Warnings and Precautions for Use

Dimetapp PSE Cough, Cold & Flu Night Relief should be used with caution in patients with: hypertension; hyperthyroidism; diabetes mellitus; coronary heart disease; ischaemic heart disease; glaucoma; prostatic hypertrophy; epilepsy; history of asthma.
The doxylamine component in the Dimetapp PSE Cough, Cold & Flu Night Relief may cause drowsiness and may increase the effects of alcohol. Drowsiness may continue the following day. Those affected should not drive or operate machinery; alcohol should be avoided.
Dimetapp PSE Cough, Cold & Flu Night Relief should not be used for chronic persistent cough accompanying a disease state, or cough associated with excessive secretions.
Dimetapp PSE Cough, Cold & Flu Night Relief should not be given to patients with or at risk of developing respiratory failure, e.g. asthma, chronic obstructive airways disease, and pneumonia.
Patients should stop use and ask a doctor if cough lasts for more than few days, comes back, or is accompanied by fever, rash or persistent headache. These could be signs of a serious condition.
This product should not be taken with another cough and cold medicines unless directed by a doctor.
Patients should not exceed the recommended dosage.
This product should be kept out of reach of children. This product should not be taken longer than few days unless directed by a doctor.
Some cases of ischaemic colitis have been reported with pseudoephedrine. Pseudoephedrine should be discontinued and medical advice sought if sudden abdominal pain, rectal bleeding or other symptoms of ischaemic colitis develop.

Use in hepatic impairment.

This product should be used in caution in patients with impaired hepatic function.

Use in renal impairment.

This product should be used in caution in patients with impaired renal function.

Use in the elderly.

The elderly may experience paradoxical excitation with the antihistamine doxylamine succinate in Dimetapp PSE Cough, Cold & Flu Night Relief. The elderly are more likely to have central nervous system (CNS) depressive side effects, including confusion.

Paediatric use.

Children may experience paradoxical excitation with the antihistamine doxylamine succinate in Dimetapp PSE Cough, Cold & Flu Night Relief.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Anticoagulant drugs (warfarin) - dosage may require reduction if paracetamol and anticoagulants are taken for a prolonged period of time.
Drugs that induce liver microsomal enzymes (e.g. alcohol, anticonvulsants), and other potentially hepatotoxic drugs may increase the risk of paracetamol-induced hepatoxicity.
Paracetamol absorption is increased by substances that increase gastric emptying, e.g. metoclopramide.
Paracetamol absorption is decreased by substances that decrease gastric emptying, e.g. propantheline, antidepressants with anticholinergic properties and narcotic analgesics.
Paracetamol may increase chloramphenicol concentrations.
Paracetamol excretion may be affected and plasma concentration altered when given with probenecid.
Colestyramine reduces the absorption of paracetamol if given 1 hour of paracetamol.
Monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs) may cause a serious increase in blood pressure or hypertensive crisis, hyperpyrexia, convulsion and may prolong and intensify the anticholinergic and CNS depressive effects.
Dimetapp PSE Cough, Cold & Flu Night Relief are contraindicated for use in patients taking medications for depression, psychiatric, or emotional conditions, or Parkinson's disease, or for 2 weeks after stopping the medication.
See Section 4.3 Contraindications for additional information.
Other sympathomimetic agents, such as decongestants, appetite suppressants and amphetamine-like psychostimulants - may cause an increase in blood pressure and additive effects.
Methyldopa and β-blockers - may cause an increase in blood pressure.
Urinary acidifiers enhance elimination of pseudoephedrine.
Urinary alkalinisers decrease elimination of pseudoephedrine.
Central nervous system (CNS) depressants (alcohol, sedatives, opioid analgesics, hypnotics) - may cause an increase in CNS depressant effects.
Selective Serotonin Reuptake Inhibitors (SSRI's) or tricyclic antidepressants may result in a “serotonin syndrome” with changes in mental status, hypertension, restlessness, myoclonus, hyper-reflexia, diaphoresis, shivering and tremor. Tricyclic antidepressants may also prolong and intensify the anticholinergic and CNS depressive effects.
Serum levels of dextromethorphan may be increased by the concomitant use of inhibitors of cytochrome P450 2D6, such as antiarrhythmics quinidine and amiodarone, antidepressants such as fluoxetine and paroxetine, or other drugs which inhibit cytochrome P450 2D6 such as haloperidol and thioridazine.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category B2)
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed.
Studies in animals are inadequate or may be lacking, but available data show no evidence of an increased occurrence of fetal damage.
Dimetapp PSE Cough, Cold & Flu Night Relief should be used in pregnancy only if the potential benefits to the patient are weighed against the possible risk to the fetus. Patients are advised to ask a doctor before use if pregnant or trying to become pregnant.
Dimetapp PSE Cough, Cold & Flu Night Relief are not recommended for breastfeeding mothers unless the potential benefits to the patient are weighed against the possible risk to the infant.

4.7 Effects on Ability to Drive and Use Machines

The doxylamine component in Dimetapp PSE Cough, Cold & Flu Night Relief may cause drowsiness and may increase the effects of alcohol. Drowsiness may continue the following day. Those affected should not drive or operate machinery; alcohol should be avoided.

4.8 Adverse Effects (Undesirable Effects)

The following adverse reactions may be associated with the use of paracetamol/ pseudoephedrine/ dextromethorphan/ doxylamine containing products.

Cardiac disorders.

Palpitation, tachycardia, or arrhythmias.

Gastrointestinal disorders.

Nausea, vomiting, stomach discomfort or constipation, dry mouth, ischaemic colitis (frequency unknown).

Eye disorders.

Blurred vision, dryness of eyes.

Immune system disorders.

Hypersensitivity.

Nervous system disorders.

Dizziness, mild drowsiness, fatigue, dystonias, headache, psychomotor hyperactivity, anxiety, tremors, (rarely) hallucinations, sedation, appetite stimulation, muscle dyskinesias and activation of epileptogenic foci. Impaired performance (impaired driving performance, poor work performance, incoordination, reduced motor skills and impaired information processing). Performance may be impaired in the absence of sedation and may persist in the morning after a night-time dose.

Renal and urinary disorders.

Urinary hesitance and retention.

Psychiatric disorders.

Agitation, anxiety, excitability, insomnia, irritability, nervousness, restlessness.

Skin and subcutaneous tissue disorders.

Rash, urticaria. Very rare cases of serious skin reactions (including severe cutaneous reactions such as Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, and Acute Generalized Exanthematous Pustulosis) have been reported.

Vascular disorders.

Hypertension, increased blood pressure.

Blood system disorders.

Haematological reactions have been reported.
Children and the elderly are more likely to experience adverse effects than other age groups.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration 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 at www.tga.gov.au/reporting-problems.

4.9 Overdose

Symptoms which may be associated with high doses (overdosage) of paracetamol/ pseudoephedrine/ dextromethorphan/ doxylamine:

Cardiac disorders.

Bradycardia, palpitation, tachycardia.

Gastrointestinal disorders.

Nausea, vomiting.

Nervous system disorders.

Convulsion, dizziness, tremor, depressed level of consciousness, dysarthria, nystagmus, somnolence, nervousness, insomnia, agitation, irritability, myoclonus.

Psychiatric disorders.

Agitation, anxiety, insomnia, irritability, nervousness, restlessness, excitability, confusional state, psychotic disorder, serotonin syndrome.

Vascular disorders.

Hypertension, increased blood pressure.

Respiratory, thoracic and mediastinal disorders.

Respiratory depression.
Overdosage with paracetamol if left untreated can result in severe, sometimes fatal liver damage and rarely, acute renal tubular necrosis.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia); 0800 764 766 (New Zealand) for advice.

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Paracetamol is a p-aminophenol derivative that exhibits analgesic and antipyretic activity. It does not possess anti-inflammatory activity. Paracetamol is thought to produce analgesia through a central inhibition of prostaglandin synthesis.
Pseudoephedrine has direct- and indirect-sympathomimetic activity and is an effective decongestant in the upper respiratory tract. It is a stereoisomer of ephedrine and has a similar action, but has been found to have less pressor activity and fewer central nervous system (CNS) effects.
Sympathomimetic agents are used as nasal decongestants to provide symptomatic relief. They act by causing vasoconstriction resulting in redistribution of local blood flow to reduce oedema of the nasal mucosa, thus improving ventilation, drainage and nasal stuffiness.
Dextromethorphan is a non-opioid cough suppressant. It is methylated dextrorotatory analogue of levorphanol, a codeine analogue. Dextromethorphan acts centrally on the cough centre in the medulla and nucleus tractus solaris to increase the cough threshold. It does not have classical analgesic, sedative or respiratory depressant effects at usual antitussive doses.
Doxylamine succinate competes with histamine at central and peripheral histamine1-receptor sites, preventing the histamine-receptor interaction and subsequent mediator release.
Doxylamine succinate is a highly lipophilic molecule that readily crosses the blood-brain barrier.
Doxylamine succinate is highly selective for histamine1-receptors but has little effect on histamine2 or histamine3-receptors. Doxylamine succinate also activates 5-hydroxytryptamine (serotonin) and α-adrenergic receptors and blocks cholinergic receptors.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

Paracetamol is readily absorbed from the gastrointestinal tract with peak plasma concentrations occurring about 10 to 60 minutes after oral administration. Paracetamol is distributed into most body tissues. Paracetamol crosses the placenta and is present in breast milk. Plasma protein binding is negligible at usual therapeutic concentrations but increases with increasing doses. The elimination half-life of paracetamol varies from 1 to 3 hours.
Paracetamol is metabolised predominantly in the liver and excreted in the urine mainly as the inactive glucuronide and sulfate conjugates. Less than 5% is excreted as unchanged paracetamol. The metabolites of paracetamol include a minor hydroxylated intermediate, which has hepatotoxic activity. This intermediate metabolite is detoxified by conjugation with glutathione, however, it can accumulate following paracetamol overdosage (more than 150 mg/kg or 10 g total paracetamol ingested) and if left untreated can cause irreversible liver damage.
Paracetamol is metabolised differently by premature infants, newborns, infants and young children compared to adults, the sulfate conjugate being predominant.
Pseudoephedrine is readily absorbed from the gastrointestinal tract. It is largely excreted unchanged in the urine together with small amounts of its hepatic metabolite. It has a half-life of about 5-8 hours; elimination is enhanced and half-life reduced accordingly in acid urine. Small amounts are distributed into breast milk.
Dextromethorphan is well absorbed from the gastrointestinal tract after oral administration. It is metabolised in the liver, exhibiting polymorphic metabolism involving the cytochrome P450 isoenzyme (CYP 2D6). It is excreted in the urine as unchanged dextromethorphan and demethylated metabolites, including dextrorphan, which has some cough suppressant activity. The plasma elimination half-life of dextromethorphan is 1.2 to 3.9 hours. However, the rate of metabolism varies between individuals according to phenotype (extensive vs poor metabolisers), with half-life being as long as 45 hours in patients who are poor metabolisers.
Doxylamine succinate is readily absorbed from the gastrointestinal tract. Following oral administration, the mean peak plasma concentration occurs after 2-3 hours. It has an elimination half-life of about 10 hours in healthy adults. It is excreted in the urine as unchanged doxylamine (60%) and metabolites (nordoxylamine and dinordoxylamine).
The major metabolic site is the liver and major metabolic pathways are N-demethylation, N-oxidation, hydroxylation, N-acetylation, N-desalkylation and ether cleavage.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

Macrogol 400, Propylene glycol, Povidone, Gelatin, Sorbitol Special-Glycerin Blend, Brilliant blue FCF and Water - purified.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store below 25°C.

6.5 Nature and Contents of Container

Dimetapp PSE Cough, Cold & Flu Night Relief are packaged in blister strips with foil backing.

Pack sizes.

2s (sample pack), 4s (sample pack), 10s, 12s, 14s, 16s, 20s.
Not all pack sizes may be marketed.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Paracetamol.

Chemically known as N-(4-Hydroxyphenyl)acetamide. It has a molecular formula of C8H9NO2 and molecular weight of 151.2. Paracetamol is a white or almost white, crystalline powder.

Pseudoephedrine hydrochloride.

Chemically known as (1S,2S)-2-(Methylamino)-1-phenylpropan-1-ol hydrochloride. It has a molecular formula of C10H16ClNO and molecular weight of 201.7. Pseudoephedrine hydrochloride is a white or almost white, crystalline powder or colourless crystals.

Dextromethorphan hydrobromide monohydrate.

Chemically known as ent-3-Methoxy-17-methylmorphinan hydrobromide monohydrate. It has a molecular formula of C18H26BrNO,H2O and molecular weight of 370.3. Dextromethorphan hydrobromide monohydrate is almost white, crystalline powder.

Doxylamine succinate.

Chemically known N,N-Dimethyl-2-[(1RS)-1-phenyl-1-(pyridin-2-yl)ethoxy]ethanamine hydrogen butanedioate. It has a molecular formula of C21H28N2O5 and molecular weight of 388.5. Doxylamine succinate is a white or almost white powder.

Chemical structure.


CAS number.

Paracetamol: 103-90-2.
Pseudoephedrine hydrochloride: 345-78-8.
Dextromethorphan hydrobromide monohydrate monohydrate: 6700-34-1.
Doxylamine succinate: 562-10-7.

7 Medicine Schedule (Poisons Standard)

S3.

Summary Table of Changes