Almost 1,000 reported cases included vomiting or diarrhoea, fever, swollen glands and injection-site swelling
THE SWINE flu vaccine caused almost 1,000 suspected adverse reactions last year, more than any other vaccine or medicine over the past five years.
However, health authorities insist the vaccine is safe and that the balance of risk and benefits for the vaccine remains positive.
The Irish Medicines Board (IMB) says the most frequently reported reactions for the vaccine have been relatively mild injection-site reactions (such as swelling), gastrointestinal problems (such as vomiting or diarrhoea) and flu-like symptoms (such as fever and swollen glands).
The Irish Timesrequested a breakdown of the drugs or vaccines responsible for the highest number of adverse reactions from the IMB under the Freedom of Information Act over the past five years.
The data shows there were about 11,500 adverse reaction reports for drugs or vaccines submitted to health authorities between 2005 and the end of 2009.
The number of adverse reactions does not necessarily represent the risk profile of each drug or vaccine, as figures for the number of people using each drug are not available. Also, it does not provide a breakdown of the number of serious or mild adverse reactions.
The figures show that the anti-psychotic drug Clozapine, also known as Clozaril, ranks second-highest in the number of adverse reactions (883).
Common adverse effects of the drug include dizziness, rapid heartbeat, constipation, excess saliva production and weight gain.
Another drug used to treat psychosis, which has attracted a relatively high number of adverse reactions, is Risperidone (154), which is more commonly known as Risperdal.
The childhood combination vaccines, which includes jabs for whooping cough, measles, mumps and rubella, ranked third highest (722) in the number of adverse reactions.
Again, health authorities insist the vaccine is safe and that most adverse reactions are mild, such as swelling, redness or fever.
Paracetamol (715), one of the most commonly used pain killers, is sometimes associated with minor issues such as hives, rashes or – if taken at high levels over a prolonged period of time – kidney damage.
Lipitor, also known as Atorvastatin, was linked to 225 adverse reactions. Studies show these typically range from joint pain and stomach upset to more serious issues such as severe muscle problems.
A spokesperson for the IMB said adverse reaction reporting rates were influenced by the seriousness of the reactions, their ease of recognition and the extent of use of a particular medicine.
In addition, reporting rates are also influenced by campaigns aimed at healthcare professionals to submit reports on specific drugs or vaccines, often as part of ongoing post-marketing surveillance.
Publicity about a particular medicine or its safety may also lead to increased reporting.
The two swine flu vaccines available in Ireland since November – GlaxoSmithKline’s Pandemrix and Baxter’s Celvapan – have been subjected to a particular vigilance.
In the first two months of 2010, more than 400 additional adverse reactions had been recorded, meaning that the overall total tops 1,400.
ADVERSE REACTIONS
Drugs or vaccines with the most adverse reactions between 2005 and 2009:
1. H1N1 vaccine:934 (Swine flu vaccine.)
2. Clozapine:883 (Anti-psychotic drug, also known as Clozaril.)
3. Childhood combination vaccines:722 (Typically the six-in-one to prevent diseases such as diphtheria, tetanus, etc.)
4. Paracetamol:715 (Pain killer.)
5. Atorvastatin:225 (Lowers blood cholesterol, also known as Lipitor.)
6. BCG vaccine:207 (A vaccine to protect against tuberculosis.)
7. Adalimumab:170 (A medication for the treatment of rheumatoid arthritis, also known as Humira.)
8. Varenicline:155 (Anti-smoking drug, also known as Champix.)
9. Venlafaxine:155 (Anti-depressant, also known as Efexor.)
10. Risperidone :154 (Anti-psychotic medicine, also known as Risperdal.)
Source:Irish Medicines Board
