Allergies happen when your immune system overreacts to a normally harmless substance like dust or pollen. Hay fever, hives and anaphylaxis are all types of allergic reactions.

Many of those affected reach quickly for antihistamines to treat mild to moderate allergies (though adrenaline, not antihistamines, should always be used to treat anaphylaxis).

If you’re using oral antihistamines very often, you might have wondered if it’s OK to keep relying on antihistamines to control symptoms of allergies. The good news is there’s no research evidence to suggest regular, long-term use of modern antihistamines is a problem.

But while they’re good at targeting the early symptoms of a mild to moderate allergic reaction (sneezing, for example), oral antihistamines aren’t as effective as steroid nose sprays for managing hay fever. This is because nasal steroid sprays target the underlying inflammation of hay fever, not just the symptoms.

Here are the top six antihistamines myths – busted.

Myth 1. Oral antihistamines are the best way to control hay fever symptoms

Wrong. In fact, the recommended first line medical treatment for most patients with moderate to severe hay fever is intranasal steroids. This might include steroid nose sprays (ask your doctor or pharmacist if you’d like to know more).

Studies have shown intranasal steroids relieve hay fever symptoms better than antihistamine tablets or syrups.

To be effective, nasal steroids need to be used regularly, and importantly, with the correct technique.

In Australia, you can buy intranasal steroids without a doctor’s script at your pharmacy. They work well to relieve a blocked nose and itchy, watery eyes, as well as improve chronic nasal blockage (however, antihistamine tablets or syrups do not improve chronic nasal blockage).

Some newer nose sprays contain both steroids and antihistamines. These can provide more rapid and comprehensive relief from hay fever symptoms than just oral antihistamines or intranasal steroids alone. But patients need to keep using them regularly for between two and four weeks to yield the maximum effect.

For people with seasonal allergic rhinitis (hayfever), it may be best to start using intranasal steroids a few weeks before the pollen season in your regions hits. Taking an antihistamine tablet as well can help.

Antihistamine eye drops work better than oral antihistamines to relieve acutely itchy eyes (allergic conjunctivitis).

Myth 2. My body will ‘get used to’ antihistamines

Some believe this myth so strongly they may switch antihistamines. But there’s no scientific reason to swap antihistamines if the one you’re using is working for you. Studies show antihistamines continue to work even after six months of sustained use.

Myth 3. Long-term antihistamine use is dangerous

There are two main types of antihistamines – first-generation and second-generation.

First-generation antihistamines, such as chlorphenamine or promethazine, are short-acting. Side effects include drowsiness, dry mouth and blurred vision. You shouldn’t drive or operate machinery if you are taking them, or mix them with alcohol or other medications.

Most doctors no longer recommend first-generation antihistamines. The risks outweigh the benefits.

The newer second-generation antihistamines, such as cetirizine, fexofenadine, or loratadine, have been extensively studied in clinical trials. They are generally non-sedating and have very few side effects. Interactions with other medications appear to be uncommon and they don’t interact badly with alcohol. They are longer acting, so can be taken once a day.

Although rare, some side effects (such as photosensitivity or stomach upset) can happen. At higher doses, cetirizine can make some people feel drowsy. However, research conducted over a period of six months showed taking second-generation antihistamines is safe and effective. Talk to your doctor or pharmacist if you’re concerned.

Myth 4. Antihistamines aren’t safe for children or pregnant people

As long as it’s the second-generation antihistamine, it’s fine. You can buy child versions of second-generation antihistamines as syrups for kids under 12.

Though still used, some studies have shown certain first-generation antihistamines can impair childrens’ ability to learn and retain information.

Studies on second-generation antihistamines for children have found them to be safer and better than the first-generation drugs. They may even improve academic performance (perhaps by allowing kids who would otherwise be distracted by their allergy symptoms to focus). There’s no good evidence they stop working in children, even after long-term use.

For all these reasons, doctors say it’s better for children to use second-generation than first-generation antihistimines.

What about using antihistimines while you’re pregnant? One meta analysis of combined study data including over 200,000 women found no increase in fetal abnormalities.

Many doctors recommend the second-generation antihistamines loratadine or cetirizine for pregnant people. They have not been associated with any adverse pregnancy outcomes. Both can be used during breastfeeding, too.

Myth 5. It is unsafe to use higher than the recommended dose of antihistamines

Higher than standard doses of antihistamines can be safely used over extended periods of time for adults, if required.

But speak to your doctor first. These higher doses are generally recommended for a skin condition called chronic urticaria (a kind of chronic hives).

Myth 6. You can use antihistamines instead of adrenaline for anaphylaxis

No. Adrenaline (delivered via an epipen, for example) is always the first choice. Antihistamines don’t work fast enough, nor address all the problems caused by anaphylaxis.

Antihistamines may be used later on to calm any hives and itching, once the very serious and acute phase of anaphylaxis has been resolved.

In general, oral antihistamines are not the best treatment to control hay fever – you’re better off with steroid nose sprays. That said, second-generation oral antihistamines can be used to treat mild to moderate allergy symptoms safely on a regular basis over the long term.

Janet Davies, Respiratory Allergy Stream Co-chair, National Allergy Centre of Excellence; Professor and Head, Allergy Research Group, Queensland University of Technology; Connie Katelaris, Professor of Immunology and Allergy, Western Sydney University, and Joy Lee, Respiratory Allergy Stream member, National Allergy Centre of Excellence; Associate Professor, School of Public Health and Preventive Medicine, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Drug companies are paying Australian doctors millions of dollars a year to fly to overseas conferences and meetings, give talks to other doctors, and to serve on advisory boards, our research shows.

Our team analysed reports from major drug companies, in the first comprehensive analysis of its kind. We found drug companies paid more than A$33 million to doctors in the three years from late 2019 to late 2022 for these consultancies and expenses.

We know this underestimates how much drug companies pay doctors as it leaves out the most common gift – food and drink – which drug companies in Australia do not declare.

Due to COVID restrictions, the timescale we looked at included periods where doctors were likely to be travelling less and attending fewer in-person medical conferences. So we suspect current levels of drug company funding to be even higher, especially for travel.

What we did and what we found

Since 2019, Medicines Australia, the trade association of the brand-name pharmaceutical industry, has published a centralised database of payments made to individual health professionals. This is the first comprehensive analysis of this database.

We downloaded the data and matched doctors’ names with listings with the Australian Health Practitioner Regulation Agency (Ahpra). We then looked at how many doctors per medical specialty received industry payments and how much companies paid to each specialty.

We found more than two-thirds of rheumatologists received industry payments. Rheumatologists often prescribe expensive new biologic drugs that suppress the immune system. These drugs are responsible for a substantial proportion of drug costs on the Pharmaceutical Benefits Scheme (PBS).

The specialists who received the most funding as a group were cancer doctors (oncology/haematology specialists). They received over $6 million in payments.

This is unsurprising given recently approved, expensive new cancer drugs. Some of these drugs are wonderful treatment advances; others offer minimal improvement in survival or quality of life.

A 2023 study found doctors receiving industry payments were more likely to prescribe cancer treatments of low clinical value.

Our analysis found some doctors with many small payments of a few hundred dollars. There were also instances of large individual payments.

Why does all this matter?

Doctors usually believe drug company promotion does not affect them. But research tells a different story. Industry payments can affect both doctors’ own prescribing decisions and those of their colleagues.

A US study of meals provided to doctors – on average costing less than US$20 – found the more meals a doctor received, the more of the promoted drug they prescribed.

Another study found the more meals a doctor received from manufacturers of opioids (a class of strong painkillers), the more opioids they prescribed. Overprescribing played a key role in the opioid crisis in North America.

Overall, a substantial body of research shows industry funding affects prescribing, including for drugs that are not a first choice because of poor effectiveness, safety or cost-effectiveness.

Then there are doctors who act as “key opinion leaders” for companies. These include paid consultants who give talks to other doctors. An ex-industry employee who recruited doctors for such roles said:

Key opinion leaders were salespeople for us, and we would routinely measure the return on our investment, by tracking prescriptions before and after their presentations […] If that speaker didn’t make the impact the company was looking for, then you wouldn’t invite them back.

We know about payments to US doctors

The best available evidence on the effects of pharmaceutical industry funding on prescribing comes from the US government-run program called Open Payments.

Since 2013, all drug and device companies must report all payments over US$10 in value in any single year. Payment reports are linked to the promoted products, which allows researchers to compare doctors’ payments with their prescribing patterns.

Analysis of this data, which involves hundreds of thousands of doctors, has indisputably shown promotional payments affect prescribing.

US research also shows that doctors who had studied at medical schools that banned students receiving payments and gifts from drug companies were less likely to prescribe newer and more expensive drugs with limited evidence of benefit over existing drugs.

In general, Australian medical faculties have weak or no restrictions on medical students seeing pharmaceutical sales representatives, receiving gifts, or attending industry-sponsored events during their clinical training. They also have no restrictions on academic staff holding consultancies with manufacturers whose products they feature in their teaching.

So a first step to prevent undue pharmaceutical industry influence on prescribing decisions is to shelter medical students from this influence by having stronger conflict-of-interest policies, such as those mentioned above.

A second is better guidance for individual doctors from professional organisations and regulators on the types of funding that is and is not acceptable. We believe no doctor actively involved in patient care should accept payments from a drug company for talks, international travel or consultancies.

Third, if Medicines Australia is serious about transparency, it should require companies to list all payments – including those for food and drink – and to link health professionals’ names to their Ahpra registration numbers. This is similar to the reporting standard pharmaceutical companies follow in the US and would allow a more complete and clearer picture of what’s happening in Australia.

Patients trust doctors to choose the best available treatments to meet their health needs, based on scientific evidence of safety and effectiveness. They don’t expect marketing to influence that choice.

Barbara Mintzes, Professor, School of Pharmacy and Charles Perkins Centre, University of Sydney and Malcolm Forbes, Consultant psychiatrist and PhD candidate, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.