The controversial drug dipyrone can treat acute headaches, but patients should be warned of the risk of potentially serious blood disorders (or "dyscrasias"), concluded a Cochrane Review team. Furthermore, most of the studies used in reaching this conclusion involved intravenous infusions of the drug, making it expensive and complex to deliver.
Dipyrone is a non-opioid painkiller that was launched in Germany in 1922 but was later banned from many countries including the USA and UK because of evidence that it might cause life-threatening blood disorders such as agranulocytosis. It is, however, a popular analgesic in many parts of the world including South America, India, South Africa, Russia and several European countries. Oral doses can be bought over the counter in Brazil and Spain.
A group of Cochrane Researchers set out to evaluate whether dipyrone was effective and safe for acute primary headaches in adults and children.
They identified four trials that involved 636 adults. None involved children. Three of the studies used intravenous dipyrone.
Taken together the evidence indicates that dipyrone is effective in treating episodic tension-type headaches and migraine in adults. The sample size, however, was too small to make any assessment of the medicine's safety.
"Given that many effective and more easily administered therapies are available, patients and clinicians will need to consider whether and in what circumstances the benefits of treatment are worth the time, trouble and expense of intravenous administration," says Dr Rebecca Gray, a Cochrane Editor who worked closely with the project.
If used, "patients should be well informed about the risk of blood dyscrasias," she adds.