New medicines aren't always better

Many people think because a medicine is new, it must be better than older medicines for the same condition — but this is not always the case. Read how to work out whether a new medicine is the best option for you.

Just because a medicine is new, does that mean it's better?

Many people think because a medicine is new, it must be better than older medicines for the same condition – but this is not always the case.

For a medicine to be approved, it must have been through clinical trials that show that it provides a benefit (i.e. it works) and what its side effects are. Mostly clinical trials compare the medicine with a placebo (i.e. a dummy pill with no active ingredient), but it is not always clear how well it compares to other medicines, simply because there is not enough information available.

When a medicine has been available for only a short time (e.g. less than 5 years), there are some reasons to be more cautious about taking it. Our knowledge about a medicine’s benefits and side effects grows with time, and new medicines have not been taken by a large number of people over a long period. This means side effects that are rare, that happen after long-term use, or that only occur in certain types of people may have not yet come to light.

The medicine rofecoxib (Vioxx) came on to the market in 1999 as a treatment for pain in arthritis. At first, it seemed that it was similar to other arthritis medicines used for pain relief, but with a lower chance of causing stomach ulcers and stomach bleeding. However, after 5 years, it became apparent that rofecoxib increased the risk of heart attack and stroke for some people taking it. It was then withdrawn from sale.

If you and your health professional are not happy with the results from your current medicine or with the alternatives, then it may well be worth considering a new medicine. Otherwise, there is probably no reason for you to rush into making a change.

Less is known about who will benefit and who will get side effects

Clinical trials for new medicines are usually carried out in fairly restricted groups of people. They often exclude people who are older, who are in general poor health (other than with the condition the medicine is expected to treat), who perhaps drink more than the recommended limits for alcohol or who are taking a number of other medicines. There may be good reasons for these restrictions – including the safety of the trials’ participants, but it does mean that little is known about using the medicine in such people.

For example, a trial of a medicine to treat high blood pressure may be carried out only with people under 65 whose only health problem is high blood pressure. Whether the medicine works as well in older people with multiple health problems will not be so certain until the medicine is used more widely in the community.

New medicines need to be tested for safety before they are approved, but in most cases they are tested in no more than a few thousand people. This means rare side effects (i.e. those occurring in fewer than 1 in 1000 people) will usually not show up until more people have taken the medicine. The result? It can look like new medicines have fewer side effects than older ones, just because there is not as much information and experience with them.

Fewer direct comparisons in clinical trials

The best way to compare different medicines is through head-to-head trials; that is, trials that directly compare the effects of two medicines. This type of trial gives the fairest comparison between two medicines because the people taking each medicine will have been carefully chosen to have very similar health problems, and the effects of each medicine will be assessed in the same way.

However, trials that directly compare medicines are usually only done several years after a medicine has been approved for use. And sometimes they are never done at all.

Video transcript

Because they take an extremely large sample, from memory, I think it was something like 12,000 people, or it was a couple of thousand people, had taken it and the incidence rates were very low, it indicated to me that it had been well researched.

And the other thing that was important for me was that it had been used for quite a while — it wasn’t a new drug on the market, which I would naturally be quite wary of. I don’t want my kids to be the guinea pigs; I would like to see the rates of any serious side effects occurring.

Weigh up the benefits and risks

You should not be influenced to take something simply because it is new. New medicines should be considered the same way as any other medicine — by weighing up both its benefits and risks for your situation. With new medicines, you need to bear in mind that there may not be enough good information available to help you do this.

Medicine Update

Medicine Update lets you know about new medicines and new PBS listings. Each issue provides an independent assessment of current information and research about a different medicine.