A medicine is only made available to the public if the clinical trials have shown that the benefits of taking the medicine outweigh the risks.
Once a medicine has been licensed, information on the medicine’s effects, both intended and unintended, is continuously recorded and updated.
Some side-effects may be serious while others may only be a mild inconvenience.
Everyone’s reaction to a medicine is different. It is difficult to predict which side-effects you will have from taking a particular medicine, or whether you will have any side-effects at all. The important thing is to tell your prescriber or pharmacist if you are having problems with your medicine.
The frequency of these side-effects is unknown
- bone problems – these may occur in infants
- breathing difficulties
- chest pain
- difficulty sleeping
- faster heart rate
- feeling restless
- feelings of excitement
- general feeling of being unwell
- hair loss – this may occur in children
- heart problems
- hypersensitivity reactions
- intolerance of heat
- intracranial hypertension – this may occur in children
- joint pain
- muscle cramps
- muscle weakness
- premature epiphyseal closure – this may occur in children
- skin rash or rashes
- weight loss
- worsening of thyroid problems – these may occur if Levothyroxine sodium is taken at a high dose for long period of time. These may include lowered blood pressure, jaundice, confusion or coma
If you feel unwell or if you have concerns about a side-effect, you will need to seek advice. If you feel very ill, get medical help straight away. Contact your prescriber, pharmacist, nurse or call 111.
The Yellow card Scheme is vital in helping the MHRA monitor the safety of the medicines and vaccines that are on the market.
Before a medicine is granted a licence so that it can be made available in the United Kingdom, it must pass strict tests and checks to ensure that it is acceptably safe and effective. All effective medicines however, can cause side effects.