Supplies of HRT drugs are running low because manufacturers are struggling to get hold of ingredients, according to reports.
The shortage is hitting almost all 200,000 British women on hormone replacement therapy and is set to continue into 2020.
FemSeven patches, manufactured by London-based firm Theramex, have been out of stock since the end of last year.
The company said its supply issue is in ‘regards to the adhesive that keeps patches attached to the skin’, and they are unlikely to be available until next year.
Most Elleste tablets are also out-of-stock, caused by ‘interruptions in the production of certain strengths of the drug’.
All high street pharmacies are being affected by the shortages, which has had a ‘domino effect’ causing supplies of alternatives to run low.
It comes as GPs warned yesterday of a surge in demand from women as ‘more and more patients are panicking’ amid the crisis.
Frustrated doctors said the shortage was adding to their workload as they were forced to spend hours finding alternative treatments.
HRT drugs, administered as patches, pills or gels, provide the oestrogen that the body stops producing during the menopause.
Thousands of women have had to switch brands of HRT drugs in recent weeks, which can cause crippling symptoms including night sweats.
More than a dozen commonly prescribed HRT drugs are out of stock or in short supply.
These include most Elleste tablets and FemSeven Sequi and Conti patches.
Mylan, which produces Elleste, explained why it was experiencing a shortage to MIMS – the Monthly Index of Medical Specialities.
‘Our manufacturing partner continues to experience interruptions in the production of certain strengths of Elleste,’ a spokesperson said.
‘We will continue to provide updates, including timing for resolution, as we receive them.’
Theramex told MIMS that both versions of its FemSeven patches are unlikely to be available again before the new year.
The firm told the Chemist and Druggist publication in April it was ‘evaluating other sources of adhesive from alternative suppliers’.
However, the company said it is a ‘time consuming process’. It did not explain why it had suddenly experienced issues with its patches.
‘We will inform clinics, hospitals [and]pharmacies when the products are available,’ a Theramex spokesperson added at the time.
The firm warned it was unable to suggest any alternative treatments for women due to no other HRT having the same composition as its patches.
Janssen, the manufacturer of Evorel – a type of patch also in short supply, told MIMS that the shortages of other products has only increased demand for Evorel.
The British Menopause Society claims it was told Evorel Conti patches are expected to be out of stock as early as September.
Janssen also said its Evorel Sequi patches would run out in the first few weeks of September, while three of its other patches – 50, 75 and 100 – will be out of stock from October.
Haitham Hamoda, chair of the BMS, told The Pharmaceutical Journal there had been ‘availability issues with many HRT products’.
‘Some of these are related to manufacturing shortages, while others are related to supply issues.
‘The BMS has been reassured that these are temporary shortages which pharmaceutical companies and their suppliers are trying to resolve.’
Professor Helen Stokes-Lampard, chair of the Royal College of GPs Professor Helen Stokes-Lampard told BBC Radio 4’s PM programme: ‘We know that there are the generic phrases like ‘supply issues’ and ‘manufacturing problems.
‘But because it’s commercially sensitive… nobody will be honest with the public and the NHS. So it’s frustrating.’
When a drug is unavailable, pharmacists try to match the patient with a similar brand that will continue to provide the necessary balance of hormones.
However, alternatives are not available for some of the out-of-stock drugs, including combined patches such as FemSeven Conti.
Lloyds’ supplier AAH Pharmaceuticals has run out of 15 of the 24 HRT brands it stocks.
Pharmaceutical retailer Alliance, which is owned by the same group as Boots, has run out of nine of 27 HRT products while a further five are low in stock.
Leeds GP Dr Richard Vautrey, of the British Medical Association, told the Daily Mail he was expecting an increase in calls from women this week.
‘That’s always the case whenever there’s a shortage of any product – people can get increasingly anxious,’ he said.
‘That’s particularly the case for products like HRT which we prescribe for three or six months at a time… it’s understandable if they get anxious if their product isn’t available.’
He said there had been a shortage of HRT over the past year, although it had become a ‘particular problem’ in the last few weeks.
‘We’ve been left playing pharmacy ping-pong,’ he said.
‘We’re issuing prescriptions, the pharmacies haven’t got them, we issue a different one, the pharmacies haven’t got that.
‘We often have to speak to the pharmacies to find out what they have actually got so we can find something as close as possible to the prescription the woman needs.
‘It takes a lot of time for GPs and it’s very frustrating for patients who find themselves taking a prescription around different pharmacies.’
Dr Hannah Short, a GP who specialises in the menopause, added: ‘More and more of my patients are panicking.’
The Royal College of GPs yesterday advised women on HRT to ‘start thinking early’ about renewing their prescription.
Helen Stokes-Lampard, chairman of the college, said the shortage was ‘depressing and demoralising for everybody’.
She said: ‘For some products, it’s just a temporary blip while they’re desperately manufacturing more.
‘That’s because there has been a domino effect – demand has peaked for their products while others are long-term unavailable.
‘For the longer term products, including the patches, it’s going to be into early 2020 before the supply issues are sorted.’
She added that GPs and pharmacists were being kept in the dark by suppliers about the shortage because the information was ‘commercially sensitive’.
The GP, who works in Lichfield, Staffordshire, added: ‘I was on call in surgery on Friday and this was a genuine and hugely frustrating problem.
‘Not just in terms of adding to GP workload, as looking for suitable alternatives is very time-consuming, but it can be distressing for patients.’
A Department of Health and Social Care spokesperson said: ‘We are continuing to monitor the situation very closely and taking every step with suppliers to resolve these manufacturing issues as quickly as possible.
‘Our priority remains to ensure patients continue to access safe and effective medicines.
‘Supplies of alternative HRT products are available and any patient affected should discuss alternatives with their doctor.’