The manufacturer of Priadel (lithium carbonate) 200mg and 400mg modified-release tablets announced in July that it is discontinuing both strengths from 6th April 2021.
In a letter to Matt Hancock, doctors and pharmacists and patient groups say the withdrawal will put pressure on already overstretched health services, substantially increase the price the NHS pays for lithium, and could put patients at risk.
Dr Gary Howsam, Vice Chair of the RCGP, said: 'Lithium is vital medication for patients with bipolar disorder. Withdrawing one common brand and increasing the price of another will be to the financial detriment of the NHS, it will increase workload on an already pressurised primary care service, and it will be confusing for patients and risk their safety as the two brands aren’t directly or easily interchangeable. We urge the health secretary to intervene in this decision for the sake of the NHS and patient care.'
Lithium (available as the brands Priadel, Camcolit and Liskonum) is a first-line treatment for patients with bipolar disorder. It is also licensed for the treatment and prophylaxis of recurrent depression, and aggressive or self-harming behaviour, and used off-licence in the treatment of cluster headaches.
Clinical guidance recommends that patients be maintained on the same brand of lithium to ensure that a consistent serum lithium level is maintained. The letter warns that switching patients on Priadel to another treatment could destabilise patients, risking either the medicine becoming less effective, or building to toxic levels causing severe side-effects including kidney damage.
Switching will require added reviews, extra tests and close monitoring of patients, the letter says, increasing pressure on primary care and mental health services and exposing patients to hazards associated with attending for blood tests during the pandemic, as well as causing anxiety about potential loss of effectiveness and risks of side-effects.
The letter also warns the withdrawal of Priadel will cause a significant increase in the cost of lithium to the NHS. Priadel currently costs £4.02 for a pack of 400mg tablets, whereas Camcolit, the other brand of lithium owned by the same manufacturer, costs £48.18 per pack of 400mg tablets. It is estimated that this will cost the NHS approximately £15 million annually in direct drug costs alone.
In addition, there is no 200mg tablet available in the Camcolit brand. Priadel Liquid remains available but contains lithium citrate rather than lithium carbonate.
Highlighting that pharmacists across the UK are already reporting shortages of Priadel, the letter asks the health secretary to 'personally intervene so that Priadel remains available in the UK with an appropriate pricing structure'.
A supply disruption alert advises that prescribers should not initiate new patients on Priadel tablets, and all patients currently prescribed the tablets should be switched to an alternative lithium brand at the nearest equivalent dose once baseline serum lithium levels have been established – with the help of mental health specialists where appropriate.
GPs should proactively identify all patients prescribed Priadel tablets (including for off-licence indications), and make early contact with all patients/carers to alert them of the need to switch. Prescribers should assess patients individually so that the most appropriate treatment is selected, and all patients should be given an individualised management plan and a lithium treatment pack.
Switching should be done without cross tapering and without interrupting treatment. Close monitoring of serum lithium levels and vigilance for relapse and tolerability are required. Further detailed advice is given in the alert.