Misuse of paracetamol causes stroke and high blood pressure

It is a household drug for many Kenyans. We take it for all manner of pains — headache, toothache, relieving high temperatures in children and for flu and colds.

The drug, paracetamol, is even used to relieve hangovers. It is considered cheap, safe and effective.

But should we think harder before we pop another pill? Do we know the science behind the ‘miracle worker’?

Experts are now warning that misuse of, and addiction to the pain killer can cause life threatening conditions.

Strangely, even the researchers who developed the drug sometime in the 1960s do not fully understand how it works, according to a study published in the American Journal of Respiratory and Critical Care.

The study findings revealed that the drug has an effect on several parts of the body, including the site of the pain and in the brain, where pain signals are interpreted.

However, they cannot tell exactly how the drug works, with the researchers concluding that paracetamol appears to inhibit the action of chemicals that are released when cells in our bodies are injured.

It also reduces headache and fever by affecting chemical messages in the area of the brain that controls our body temperature.

Paracetamol is an active ingredient in more than 600 medications. It comes in different brand names depending on the country, including Tylenol, Panodil, Pinex and Pamol. Some of the Kenyan examples are Panadol and Sonamol.

Not regulated

For 62 years, the drug has gained popularity in the country, with more than 10,000 kilogrammes being sold each year. It is one of the drugs that is not regulated and anyone can buy it over the counter.

Dr Tom Micklewright, the author of the study and a general practitioner in the National Health Service (NHS) in the United Kingdom, said that all they know is that paracetamol works by disrupting messages in different parts of the brain involved in processing pain.

However, prolonged use of the drug can cause hepatotoxicity and other complications. Hepatotoxicity is injury to the liver or impairment of the liver function.

“Heavy use of alcohol and regular use of paracetamol in management of alcohol induced hangover are discouraged as this can increase the risk of liver and kidney diseases. Due to its safety, paracetamol is widely misused for the relief of alcohol induced hangover symptoms,” said the study.

The research by University of Edinburgh researchers also revealed that patients taking the drug over many months increases their chances of developing high blood pressure, heart attacks and strokes.

Randomised trial

In a randomised trial, 110 volunteers, two-thirds of whom were taking drugs for high blood pressure, or hypertension were given 1g of paracetamol four times a day for two weeks.

They were then given dummy pills, or placebos, for another two weeks.

The findings showed that those who were placed on paracetamol had increased blood pressure, more than those on a placebo, said Prof James Dear, chair of Clinical Pharmacology at the University of Edinburgh.

Another large US study found a link between long-term paracetamol use and increased risk of heart attacks.

The researchers have since advised doctors to consider reducing the dosage of paracetamol on patients with chronic pain to reduce the risk of them developing other diseases.

Dr Tom Micklewright stressed the importance of always reading the label and information leaflet before taking any medication, and paracetamol is no exception.

Reading up on paracetamol before you take it helps make you aware of any possible side effects and how it will work best for you. If you are unsure, you should consult your GP before taking paracetamol.

"This is particularly important if you've previously had an allergic reaction to it, have liver problems, take medication for epilepsy or tuberculosis, are on warfarin, regularly consume large amounts of alcohol or take other medications," said Dr Micklewright.