Promethazine Theoclate

Indications

Promethazine Theoclate Tablets are an anti-emetic (anti-sickness drug) which helps to prevent, and treat nausea and vomiting, including travel sickness, and vertigo. Promethazine Theoclate contains promethazine which belongs to a group of medicines called phenothiazines. Your doctor may prescribe this medicine for giddiness or light-headedness (vertigo), or for sickness after an operation, and in such cases the tablets should be taken as instructed by your doctor.

Pharmacology

Promethazine Theoclate works by stopping histamine from binding to its receptors in an area in the brain known as the vomiting centre. The vomiting centre is responsible for causing feelings of sickness and for the vomiting reflex. It is activated when it receives nerve messages from the vestibular apparatus in the middle ear.

The vestibular apparatus provides constant feedback to the brain about the position of our body. When something disturbs the vestibular apparatus, such as movements of the head when travelling by boat or car, nerve signals are sent from the vestibular apparatus to the vomiting centre. This can cause the symptoms of motion sickness, such as nausea, dizziness or spinning sensations (vertigo) and vomiting.

By blocking the histamine receptors in the vomiting centre, Promethazine Theoclate prevents disturbances in the middle ear from activating the vomiting centre.

Dosage And Administration

To prevent travel sickness on short journeys: Promethazine Theoclate should be taken at least one or two hours before travelling. Adults and children aged over 10 years should take one tablet. Children aged 5 to 10 years should be given half a tablet.

To prevent travel sickness on long journeys: Promethazine Theoclate should be taken at bedtime each night during the journey, starting the night before you travel. Adults and children aged over 10 years should take one tablet. Children aged 5 to 10 years should be given half a tablet.

To treat travel sickness: Adults and children over 10 years should take one tablet as soon as you feel sick, followed by a second tablet the same evening. Take a third tablet the following evening if necessary. Children aged 5 to 10 years should treated in the same way, but with half a tablet each time.

For sickness and vomiting due to other causes, and for treating vertigo: Adults and children aged over 10 years should take one tablet up to three times a day. Children aged 5 to 10 years should be given half a tablet up to three times a day. Alternatively you should follow the instructions given by your doctor.

Interaction

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start taking Promethazine Theoclate. Similarly, check with your doctor or pharmacist before taking any new medicines while taking Promethazine Theoclate, to make sure that the combination is safe.

Promethazine Theoclate should not be taken by anyone who has taken a type of antidepressant called a monoamine oxidase inhibitor (MAOI), eg phenelzine, tranylcypromine, isocarboxazid, in the previous 14 days.

You are more likely to feel drowsy if you take Promethazine Theoclate with any of the following (which can also cause drowsiness):

  • alcohol
  • antipsychotic medicines, eg chlorpromazine
  • barbiturates, eg phenobarbital
  • benzodiazepines, eg diazepam, temazepam
  • sedating antihistamines, eg chlorphenamine, brompheniramine, hydroxyzine
  • sleeping tablets, eg zopiclone
  • strong opioid painkillers, eg morphine, codeine, dihydrocodeine, tramadol
  • tricyclic antidepressants, eg amitriptyline.

Contraindications

  • Children under five years of age.
  • People with reduced awareness, slow reactions or extreme drowsiness caused by medicines or illnesses that reduce activity in the central nervous system.
  • People who have taken a type of medicine called a monoamine-oxidase inhibitor antidepressant (MAOI) in the past 14 days.
  • Children and adolescents who have signs and symptoms suggestive of Reye's syndrome.
  • People who are allergic to any ingredients of the tablets.
  • Promethazine Theoclate tablets contain lactose and should not be taken by people with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption.

Side Effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with promethazine. Just because a side effect is stated here does not mean that all people using Promethazine Theoclate will experience that or any side effect.

  • Drowsiness or feeling tired.
  • Dizziness.
  • Restlessness.
  • Headache.
  • Nightmares.
  • Blurred vision.
  • Difficulty passing urine.
  • Dry mouth.
  • Confusion.
  • Feeling disorientated.
  • Unexpected increase in excitability in children.
  • Increased sensitivity of the skin to sunlight (photosensitivity). If affected you should avoid sun lamps and direct sunlight while you are taking this medicine.
  • Loss of appetite.
  • Awareness of your heartbeat (palpitations).
  • Abnormal heartbeats (arrhythmias).
  • Low blood pressure (hypotension).
  • Abnormal movements of the hands, legs, face, neck and tongue, eg tremor, twitching, rigidity (extrapyramidal effects).
  • Blood disorders.

Pregnancy And Lactation

If you are pregnant you should not take Promethazine Theoclate without consulting your doctor first. Promethazine Theoclate should only be used during pregnancy if essential, and only if the expected benefit to the mother outweighs any potential risks to the developing baby. It should not be used during the last two weeks of pregnancy, because if taken during this time it may cause irritability or excitement in the baby after birth. Seek further medical advice from your doctor.

Small amounts of Promethazine Theoclate may pass into breast milk. This is not expected to be harmful to a nursing infant with occasional short-term use of Promethazine Theoclate, but there is a risk that it may cause drowsiness, irritability or excitement in a newborn baby. If you are breastfeeding you should not take Promethazine Theoclate without getting medical advice from your doctor first.

Precautions And Warnings

Promethazine Theoclate tablets can make some people feel drowsy, dizzy, confused or disorientated and this may reduce your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you and you are sure it won't affect your performance. If your child is affected in this way they should avoid potentially hazardous activities such as riding bikes. You should not leave your child unattended after giving them this medicine.

Avoid drinking alcohol while taking Promethazine Theoclate because this is likely to make the above effects more likely or worse.

Promethazine Theoclate tablets may make your skin more sensitive to sunlight than usual, so you should avoid exposing your skin to direct sunlight or sunlamps until you know how your skin reacts. If you can't avoid strong sunlight you should use a sunscreen lotion or make sure your skin is protected with clothing.

This medicine may interfere with some pregnancy tests, causing false negative or false positive results.

If you are due to have any skin prick tests to diagnose allergies you should stop taking Promethazine Theoclate at least 72 hours before the tests. This is because antihistamines can prevent or lessen the skin reactions that indicate an allergy, and so can make the test results unreliable.

Therapeutic Class

Anti-emetic drugs, Miscellaneous sedatives & hypnotics, Sedating Anti-histamine.

Storage Conditions

Store between 15-30° C. Protect from light.