Circadin Side Effects

Home › Medicine Side Effects › Circadin

Answer the side-effect intent for circadin without diagnosing; distinguish common from serious reactions and give safe next-step/reporting guidance.

What is Circadin?

Circadin contains the active ingredient Melatonin.

• Active ingredient — Melatonin
• Registration number — 56/2.2/0389
• Registration holder — Teva Pharmaceuticals (Pty) Ltd

It is approved for:

• The active substance of CADIATEV, melatonin, belongs to a natural group of hormones produced by the body
• S4 CADIATEV is used on its own for the short-term (up to 13 weeks) treatment of primary insomnia (persistent difficulty in getting to sleep or staying asleep, or poor quality of sleep) in patients aged 55 years and older
• ‘Primary’ means that the insomnia does not have any identified cause, including any medical, mental, or environmental cause

Common side effects of Circadin

Not everyone gets side effects. The effects below are those listed in the South African approved leaflet, grouped using the leaflet’s own frequency wording.

Less frequent side effects

• a reactivation of the chickenpox virus in the body, causing a painful rash
• reduced number of white blood cells in the blood
• reduced blood platelets, which increases risk of bleeding or bruising
• a high level of a certain type of fat (triglycerides) in the blood
• low serum calcium levels in the blood, low sodium levels in the blood
• irritability, nervousness, restlessness, insomnia, abnormal dreams, nightmares, anxiety, migraine, headache
• altered mood, aggression, agitation, crying, stress symptoms, early morning awakening, increased sex drive, depressed mood, depression
• restlessness associated with increased activity, dizziness, tiredness, disturbance in attention, memory impairment
• lethargy (tiredness, lack of energy), restless legs syndrome, poor quality sleep, ‘pins and needles’ feeling, migraine, fainting
• feeling of drowsiness
• visual impairment, excessive tearing
• blurred vision
• vertigo (a feeling of dizziness or ‘spinning’), episodes of dizziness and a sensation of spinning with certain head movements
• high blood pressure, hot flushes
• upper abdominal pain, stomach pain, indigestion, mouth ulceration, dry mouth, nausea
• acid reflux, stomach disorder, inflammation of the stomach lining
• blistering in the mouth, tongue ulceration, stomach upset, vomiting, abnormal bowel sounds, wind, excess saliva production, bad breath, abdominal discomfort, gastric disorder
• abnormal liver function, increased liver enzyme functions, abnormal increase of bilirubin in the blood
• eczema, skin rash, hand dermatitis, itchy rash, nail disorder, psoriasis, night sweats, itching, rash, dry skin, excessive sweating
• presence of red blood cells in the urine
• excretion of glucose in the urine
• excess proteins in the urine, passing large volumes of urine, urinating during the night
• pain in extremities, arthritis, muscle spasms, neck pain, night cramps
• menopausal symptoms
• prolonged erection that might be painful, inflammation of the prostate gland
• feeling of weakness, tiredness, pain, thirst
• changes in the composition of your blood which could cause yellowing of the skin or eyes, inflammation of the skin
• weight increase
• abnormal blood electrolytes. Side effects with unknown frequency:
• swelling of mouth or tongue, swelling of the skin
• abnormal milk secretion

Serious side effects and warning signs

This leaflet does not set out a separate list of serious side effects. The general warning signs below apply to any medicine.

General warning signs that apply to any medicine

How long can side effects last?

How long a side effect lasts depends on the effect, the product, how long it has been used, and the person. Some effects ease within days as the body adjusts. Others continue for as long as the product is used. A few can persist after stopping, and some need review rather than waiting.

• Settling effects — mild effects that ease over the first days or weeks of use
• Ongoing effects — effects that continue while the product is being used and improve after stopping
• Persistent effects — effects that continue after stopping and need medical review
• Delayed effects — effects that appear after weeks or months rather than immediately

Which of these applies to a particular effect is a clinical question. If a side effect is not settling, is getting worse, or is affecting your daily life, that is worth a conversation with a pharmacist or doctor regardless of how long it has been going on.

Factors that may affect side effects

The approved leaflet identifies the following cautions and factors.

Do not use it at all if

• if you are hypersensitive (allergic) to melatonin or to any other ingredients of CADIATEV (listed in section 6)
• if you are pregnant or breastfeeding

Use with care, and tell your doctor, if

• if you suffer from liver or kidney problems. No studies on the use of CADIATEV in people with liver or kidney diseases have been performed, you should speak to your doctor before taking CADIATEV as its use is not recommended
• if you have been told you suffer from an autoimmune disease (where the body is ‘attacked’ by its own immune system). No studies on the use of CADIATEV in people with auto-immune diseases have been performed; therefore, you should speak to your doctor before taking CADIATEV as its use is not recommended
• smoking may make CADIATEV less effective, because the components of tobacco smoke can increase the breakdown of melatonin by the liver. Children and adolescents: Do not give this medicine to children below 18 years as it has not been tested and its effects are unknown

Pregnancy and breastfeeding

• If you are pregnant or breastfeeding, think you may be pregnant or are planning to have a baby, please consult your doctor, pharmacist, or other healthcare provider for advice before taking CADIATEV
• Do not take CADIATEV if you are pregnant or breastfeeding your baby while taking CADIATEV

Interactions and medicines to check

The approved leaflet names these interactions.

• Always tell your healthcare provider if you are taking any other medicine
• (This includes all complementary or traditional medicines.) Fluvoxamine (used for the treatment of depression and obsessive-compulsive disorder), psoralens (used in the treatment of skin disorders e.g., psoriasis), cimetidine (used in the treatment of stomach problems such as ulcers), quinolones and rifampicin (used in the treatment of bacterial infections), oestrogens (used in contraceptives or hormone replacement therapy) and carbamazepine (used in the treatment of epilepsy)
• Adrenergic agonists/antagonists (such as certain types of medicines used to control blood pressure by constricting blood vessels, nasal decongestants, blood pressure lowering medicines), opiate agonists/antagonists (such as medicines used in the treatment of drug addiction), prostaglandin inhibitors (such as nonsteroidal anti-inflammatory medicines), antidepressant medication, tryptophan, and alcohol
• Benzodiazepines and non-benzodiazepine hypnotics (medicines used to induce sleep such as zaleplon, zolpidem and zopiclone)
• Thioridazine (for the treatment of schizophrenia) and imipramine (for the treatment of depression)
• CADIATEV with food, drink, and alcohol: Take CADIATEV after you have eaten
• Do not drink alcohol before, during or after taking CADIATEV, because it reduces the effectiveness of CADIATEV

What to do if you experience side effects

If you think you are having a side effect, the response depends on how severe it is. Use the warning signs above first — if any of those apply, treat it as urgent.

If the symptom is severe or frightening

Get medical help immediately. Call 10177 for an ambulance, or 112 from a mobile phone, or go to the nearest emergency department. Take the product and its packaging with you if you can.

If the symptom is mild but bothering you

• Write down what the symptom is, when it started, and how it relates to when you take the product
• Check the leaflet that came with the product to see whether the symptom is listed
• Speak to your pharmacist — for many questions this is the fastest route to a useful answer
• Contact the prescriber if the symptom is affecting your daily life or is not settling

You can also report a suspected side effect in South Africa. Reporting does not replace getting medical advice, and you do not need to be certain the product was the cause.

When to seek urgent medical help

Some symptoms need medical attention straight away rather than an appointment in a few days. Do not wait to see whether they settle.

Get same-day medical advice if you have

• A high fever, or a rash together with feeling generally unwell
• Yellowing of the eyes or skin, or unusually dark urine
• Unusual bruising or bleeding that you cannot explain
• Severe or persistent vomiting or diarrhoea, especially if you cannot keep fluids down
• A sudden change in mood, or thoughts of harming yourself
• Any symptom that is rapidly getting worse

How to report a suspected side effect in South Africa

South Africa has an official system for reporting suspected side effects, run by the South African Health Products Regulatory Authority (SAHPRA). Reports from the public and from healthcare professionals are how safety signals get detected after a product is already in use.

Who can report

Anyone can report — you do not have to be a healthcare professional, and you do not need to prove that the product caused the problem. A suspicion is enough. Patients, caregivers and family members can all submit a report.

What to have ready

• The name of the product, its strength and form, and the batch number if you have it
• Why it was being used, and when it was started and stopped
• What the suspected reaction was, when it began, and how long it lasted
• Any other medicines, supplements or remedies being used at the same time
• Basic details about the person affected — age and sex are usually enough

How to report

SAHPRA accepts adverse reaction reports through its e-Services reporting system and through the Med Safety mobile app. Healthcare professionals can also report through the same routes. Current forms and access points are published on the SAHPRA site.

• SAHPRA Health Products Vigilance — the main vigilance and reporting hub
• SAHPRA e-Services — current adverse reaction reporting access

For a fuller walkthrough see how to report an adverse drug reaction.

Related pages

• minoxidil side effects

← Back to more medicine side effects.