What is mycophenolate mofetil?

Mycophenolate mofetil was developed as an immunosuppressive drug for transplant patients. It has been used for a wide variety of skin problems including psoriasis, eczema and other inflammatory disorders.

How does mycophenolate mofetil work?

Mycophenolate mofetil acts by decreasing the activity of white blood cells in the body, thus suppressing the immune system. You may need to take mycophenolate mofetil for 3 months before you notice any change in your condition. If you find it effective, mycophenolate mofetil can be continued long-term.

When is mycophenolate mofetil used?

Mycophenolate mofetil is used off-licence for adults and children with severe eczema who are troubled with repeated, widespread flare-ups of the disease, or who have eczema that is hard to control with topical treatments alone.

It is used alone or in conjunction with other immunosuppressants, such as ciclosporin.

Who should NOT take mycophenolate mofetil?

Mycophenolate mofetil should not be taken during pregnancy as it may cause birth defects.

Women should use two forms of effective contraception throughout treatment and for 6 weeks after the last dose. Pregnancy tests may be performed before starting treatment and repeated throughout the course of treatment as necessary. If you wish to plan for a pregnancy or in the event of a pregnancy, you should contact your consultant immediately. Men (including those who have had a vasectomy) should use condoms during treatment and for 90 days (13 weeks) after the last treatment dose. Female partners of men treated with mycophenolate mofetil should also use contraception during their partner’s treatment and for 90 days after their partner’s last treatment dose.

Since mycophenolate mofetil may be excreted into breast milk, it should not be used by breastfeeding women.

What are the side effects of mycophenolate mofetil?

Most people tolerate mycophenolate mofetil well. Although the risk of infection is less than with azathioprine or ciclosporin, regular blood tests are necessary to check for infection and anaemia.

Blood tests are done on assessment, then weekly, then every 2–3 months to measure blood counts, urea, electrolytes and haemoglobin. You should have an annual flu jab when taking mycophenalate mofetil.

Mycophenolate mofetil may cause some photosensitivity, so extra precautions are needed when exposed to ultraviolet light, including sunlight.

Other side effects (more common with higher doses) include nausea, vomiting and diarrhoea.
As with other immunosuppressants, long-term use of this drug may increase the risk of cancer.

Does mycophenolate mofetil interact with other drugs?

The absorption of mycophenolate mofetil can be reduced by antacids, indigestion remedies, iron tablets and the cholesterol-lowering treatment cholestyramine. Mycophenolate mofetil can reduce the absorption of anti-epileptic drugs (e.g. phenytoin). The tranquilliser clozapine may decrease the white blood cell count and thereby lower the body’s defence against infection. Mycophenolate mofetil interacts with certain antiviral drugs (e.g. aciclovir and ganciclovir). Antibiotics such as co-amoxiclav, metronidazole, norfloxacin and rifampicin may decrease the effect of mycophenolate mofetil.

Can I have immunisations while on mycophenolate mofetil?

You should avoid immunisations containing live weakened viruses (attenuated vaccines) such as polio drops, measles, mumps and rubella (MMR), yellow fever, chicken pox, shingles and nasal flu vaccines (the annual flu and pneumococcal vaccines are safe and recommended).

If you require immunisation with a live vaccine, mycophenolate mofetil should be stopped 6 months before the vaccination and not taken until 2 weeks after the vaccination has been given.

Avoid contact with infants who have had oral polio drops (no longer routinely used in the UK). Other inactivated vaccines are safe to give but may be less effective in protecting you if you continue to take mycophenolate mofetil.