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Doctors are urging stronger written warnings that painkilling drugs can cause serious headaches, a problem that could afflict thousands of New Zealanders.
So-called "rebound" headaches have been reported from paracetamol and ibuprofen, available from supermarkets, and from stronger prescription medicines.
An Auckland woman said last night that she suffered "incredibly severe" headaches when taking the maximum dose of paracetamol for several days while recovering from the caesarean birth of her first child.
The headaches were so bad she needed to keep herself completely still in a darkened room to reduce the pain. She suspected the pills were the cause and said that soon after she stopped taking them the headaches ceased.
Pharmac figures show paracetamol was the most commonly prescribed state-subsidised drug in the 12 months to June 2006; more than 1.4 million scripts were written for it.
British newspapers report that 1 per cent of the population suffers from recurrent headaches caused by painkillers and that the problem is more common in women than men - a figure that suggests 40,000 New Zealanders are afflicted.
An American study found that 20 per cent of doctors' patients suffered rebound headaches from analgesics.
New Zealand health practitioners were yesterday unaware of any New Zealand statistics on rebound headaches, but said it was a significant problem and agreed that stronger warnings were needed to accompany pain medications sold at supermarkets.
"It's a real problem," said College of General Practitioners president Dr Jonathan Fox.
He said he had had migraine patients who seemed to need ever more frequent medication - until it was found to be causing headaches.
"They needed to be weaned off everything," Dr Fox said.
"Even with paracetamol, people will pop a couple every day for headache and it may be exacerbating the problem. You take them off it and ... things may initially seem to get worse - that's just the rebound - then things should settle down ... It varies, but usually within a week or so."
Dr Fox said providing more literature with over-the-counter medications warning of the potential side-effects would be a good idea.
Neurological Foundation medical adviser Dr Jon Simcock, who thought the figure of 1 per cent of the population too high, said it would be useful to have more information available to consumers, but the existing supermarket sales of painkillers should be allowed to continue.
Waikato pharmacist Richard Heslop said rebound headaches could occur with any painkiller.
Stronger written warnings would help, but many people did not read medicine leaflets. He urged that paracetamol and ibuprofen be restricted to pharmacy sales.
A Health Ministry spokesman said appropriate information was already printed on over-the-counter packs of paracetamol, warning against prolonged use without medical advice.
