Cozaar (losartan potassium) is heralded by its manufacturer Merck Sharp & Dohme as being "the first of a new class" for treating hypertension, or high blood pressure.
The class in question is known as angiotensin II receptor blockers, and is supposed to be a safer alternative to the ACE inhibitor family. One test that bears out this theory found that losartan potassium did not trigger the dry cough usually associated with ACE inhibitors, which frequently gets so bad that treatment has to be stopped.
Around 5 million patients around the world have been treated with Cozaar over three years, and with few side effects. Any effects, says the manufacturer, have been mild and transient, and most have had an incidence rate similar to a placebo; in other words, the effect could have happened, anyway.
So has Merck produced the first perfect drug? Not if you're a pregnant woman still in your second or third trimester. Taking the drug could cause you to abort the baby, or it could be born with a serious handicap.
And, for the rest of the population, the argument that the drug's side effects are no worse than a placebo doesn't quite add up. Incidence of muscle cramping is much higher, as is dizziness, insomnia, sinusitis and upper respiratory infection.
The manufacturer also says the drug is well tolerated with others again, not quite the case. Patients who are hypersensitive to aspirin and penicillin suffered swelling of the lips and eyelids and facial rashes when given Cozaar.
Other reactions that have been observed include diarrhoea, muscle pain and migraine.
Despite this, Cozaar is probably a safer option than the ACE inhibitors, which may not be saying quite as much as the manufacturer would have you believe.