London - Drugs for blood pressure, acne, depression – even common painkillers – can lead to hair loss, according to a report by scientists at the University of Melbourne. And other drugs can turn a brunette into a redhead, or make straight hair curly.
Hair loss or thinning can occur up to a year after taking medication but, thankfully, in most cases, hair loss or any other changes are reversible.
Doctors say it is important that patients see their GP if they notice any unusual hair loss (do not stop taking any medication without seeing your doctor).
They can be switched to other drugs, if appropriate, or the dose can be reduced. In other cases, patients can be reassured the effects are unlikely to be permanent.
“The cause of hair loss or change is often unknown, but you must always consider the effects of drugs,” says Professor Sam Shuster, professor of dermatology at Newcastle University.
“When drugs do affect the hair, the change is usually mild and reverses when the drug is stopped. So you may want to tolerate the change, because of the important effect the drug is having in restoring your health.’
It’s well known, for instance, that chemotherapy drugs kill cancer cells, but also attack other fast-growing cells in the body, such as hair roots. This is why patients can start to lose their hair within two to three weeks of starting treatment.
The drugs can also affect texture and shade, research shows, but hair should re-grow three to 10 months after treatment has ended.
In many cases, medications are thought to affect hair by interfering with its growth cycle, which has three distinct stages. In the growing period, which lasts between three and five years on the scalp, hair grows by around 1cm a month.
That’s followed by a shorter, two-week stage, known as the intermediate phase, where the hair follicle is prepared for releasing the hair.
In the final, three-month phase — the telogen phase or ‘resting’ phase — the hair stops growing and eventually falls out.
After three months, the follicle starts to grow a new hair. Fortunately, this happens randomly all over the scalp. If it didn’t, the hair would be shed in clumps.
Here we reveal the drugs that may be causing your hair to change …
Epilepsy drugs
Some drugs used for epilepsy and other disorders such as migraine have been linked to hair loss – and they may even make hair curly.
In a recent study involving more than 200 patients at Razi Hospital in Iran, 3.5 percent given the drug sodium valproate experienced hair loss or curling.
Antidepressants
Fluoxetine – better known as Prozac – is the most commonly reported antidepressant to cause hair loss, according to researchers in Melbourne.
The team say increased hair loss occurs up to one year after the start of medication and stops when therapy ends.
Tricyclic antidepressants, which include imipramine, amitriptyline and doxepin, may occasionally cause hair loss, the Australian study found. But “This type of hair loss is reversible,” says Shuster.
The drug lithium, commonly used to treat bipolar disorder, is linked to a 12 percent risk of hair thinning, according to some studies.
Shuster cautions that patients should never stop taking the drugs without consulting their GP. “The loss of a few hairs is trivial compared with the loss of your mental health,” he says.
Psoriasis
This skin condition leads to a build-up of painless, silvery scaly patches all over the body – it’s thought to be caused by the body over-producing skin cells.
Some treatments target this by slowing down the production of new skin cells, but this can have the unfortunate side-effect of changing hair colour or even making it curly.
One drug, acitretin, has been shown to darken hair in some patients, while another drug, etretinate, has been found to lighten hair from a black-brown shade to reddish-brown within three months.
Scientists believe that the drugs can also interfere with the structure of the hair’s root, resulting in kinks or curls.
In all the cases reported, colour and straightness returned after treatment ended.
Contraceptive Pill
Hair loss has been reported among women who stop taking the Pill after long-term use.
“Fortunately, the hair changes that occur with the pill are mild and infrequent, even with the progesterone-based pills,” says Professor Shuster.
“But like all medications, you have to balance this against the wanted effect.”
Beta blockers
Widely used to treat high blood pressure, these drugs have also been linked to hair thinning.
The Melbourne researchers say two particular beta blockers, metoprolol and propranolol, have been shown to lead to reversible hair loss.
Another group of drugs used for blood pressure, angiotensin-converting enzyme inhibitors, may also be associated with hair loss, say the Melbourne team.
Acne pills
Retinoids, which are derived from vitamin A, are widely used in dermatology for a number of conditions, including acne.
They may also cause hair loss in a small number of patients, according to the Melbourne study. The risk increases with the dose, and other body hair may be affected, too.
Ibuprofen
Small studies have linked the painkiller to hair loss. A recent New Zealand report described hair loss as a possible complication, affecting fewer than one in 100 users. In a US study based on a sample of 21 people using ibuprofen, 15 reported thinning or loss of hair.
Once the medication is discontinued, hair loss reduces over eight to nine months, say the researchers.
Blood thinners
Patients at risk of blood clots are often prescribed a type of blood-thinning medication called low molecular weight heparin.
This may trigger hair loss by damaging the hair follicles, according to a University of California study. The blood thinner warfarin may also trigger hair loss, but this is much less common, say the California team. – Daily Mail