Unfortunately, some people experience sudden, severe, life-threatening allergic reactions to some of the muscle-relaxant medications that are used during anaesthesia. If a person has recently used pholcodine, a common ingredient in over-the-counter cough medicines, the risk of having one of these life-threatening reactions to a muscle relaxant is increased. 

The cough suppressing medication pholcodine can create sensitivity to the type of muscle relaxant drugs that are commonly used in procedures that require general anaesthesia, so that if someone takes pholcodine, and then later requires general anaesthesia their chance of having a severe, life-threatening allergic reaction is higher.

Anaesthetises across Australia have been advocating for this product to come off the shelves for years, after suspicion was first raised in Norway back in 2007, when they recognised that patients in Norway were experiencing 10 times the rates of death due to complications of anaesthesia compared to Sweden, where pholcodine wasn’t available over-th-counter. Norway removed over-the-counter access to pholcodine and saw this death rate drop substantially.

This doesn’t mean people will need to go without cough medicines all together - there are safe alternatives that will continue to be available. People seeking to manage coughs and colds should discuss with their pharmacist or general practitioner to find out what other options exist and to talk through what may be the best option for them.

Another opiate bites the dust.

Pholcodine is  a derivative of morphine. It's been around for a long time. It was patented in 1952 and has been available for relief of dry cough for many years. It's surprising that concern about its side effects have taken so long to emerge. Now that they have, the regulator of pharmaceutical products in Australia, the Therapeutic Goods Administration, has acted appropriately in taking it off the market. In the pharmaceutical 'bible', the Merck Index, the entry on Pholcodine ends with the caution that abuse of the drug can lead to habituation or addiction. It's amazing that it lasted so long, but then, it's only in recent years that use of another widely-used opiate, Codeine, has been restricted.

Pholcodine is a cough suppressant that works selectively on the cough centre in the brain to control and help stop coughing. It does not cause an excited state and there is no evidence of physical dependence after prolonged use, in contrast to codeine for example. That is why it has been considered safe and was available without a prescription over the counter. 

This now plays a big role in the decision of the TGA today and also by EMA in Europe to withdraw pholcodine. If patients have been taking pholcodine there is an increased risk for an allergic reaction to neuromuscular blocking agents used during anaesthesia. Especially in emergency situations, emergency doctors may not know if the patient has been taking pholcodine in the last 12 months. 

Over the last 12 months, a recent study conducted by EMA and Western Australia has shown that pholcodine was a risk factor in developing sudden, severe and life-threatening allergic reactions during anaesthesia. 

What can you do if you have taken pholcodine? If you need anaesthesia in the next 12 months you should advise your health professional.*"

* This comment has been updated from a previous version which incorrectly stated " If you need anaesthesia in the last 12 months you should advise your health professional

The Therapeutic Goods Administration (TGA), has cancelled products containing pholcodine from the Australian Register of Therapeutic Goods and is recalling pholcodine-containing medicines from pharmacies. Pholcodine was used to treat dry productive cough, it is a derivative of the pain reliever codeine, but unlike codeine, it has little or no pain relieving effect and fewer side effects.

However, it has been found to increase allergic and anaphylactic responses to neuromuscular blocking agents (NMBAs) used in surgery to relax muscles. This is thought to be due in part to a common molecular structure recognised by the immune system, even though pholcodine and NMBAs have very different mechanisms of action.

Phlocodine is not very effective in clinical trials at suppressing cough, and while anaphylaxis to NMBAs is rare, it is very serious and potentially fatal. Since it can be very difficult to determine if someone about to undergo anesthesia has taken a pholcodine-containing medicine, the risk was determined to be too great given the minimal benefit of pholcodine for it to remain a registered medicine.

Since pholcodine was voluntarily withdrawn in Norway, there was a reduction in NMBA anaphylaxis cases over the following three years, supporting the case for withdrawal.

As a pharmacist and clinical epidemiologist, I strongly endorse the Therapeutic Goods Administration's decision to deregister pholcodine. Pholcodine is a cough suppressant that has been associated with severe allergic reactions that can be life-threatening. These reactions can occur even in patients who have no history of allergy to any other medication.

The decision to remove pholcodine from the market is based on strong scientific evidence, including several studies that have shown a clear link between the use of pholcodine and an increased risk of anaphylaxis. As healthcare professionals our primary concern is the safety and well-being of our patients and removing a medication that poses such a significant risk is a necessary step in ensuring that patient safety is maintained. In addition, there are several alternative medications available that can be used to treat coughs without the risk of anaphylaxis. These alternatives have been proven to be just as effective, and they offer a safer option for patients who may be at risk of allergic reactions.

Overall, the decision to deregister pholcodine is a welcome one, and it reflects the commitment of the TGA to patient safety. As healthcare professionals, we must always prioritize the safety and well-being of our patients, and this decision is a significant step in that direction.