Florinef

Florinef contains fludrocortisone acetate, a man-made steroid that does the job of aldosterone, the hormone the adrenal glands use to hold on to sodium and water and to get rid of potassium. When the adrenal glands fail, salt is lost, blood volume falls and blood pressure drops, causing dizziness on standing, tiredness and salt craving. The UK SmPC lists two uses: partial replacement therapy in primary adrenocortical insufficiency (Addison's disease) and treatment of salt-losing adrenogenital syndrome, a form of congenital adrenal hyperplasia. It is normally taken together with hydrocortisone or another glucocorticoid, which replaces cortisol.

All Florinef options on this page are 100 microgram (0.1mg) tablets; the two dosage labels on the order form describe the same strength. Packs of 30, 60 and 90 tablets are listed under one label and 120, 180, 270 and 360 tablets under the other.

For adults, the SmPC gives a daily range of 50 to 300 micrograms by mouth; for a 50 microgram dose, the SmPC points to other suitable fludrocortisone products. For children, half a tablet to one tablet a day is described, adjusted to age, weight and severity. In practice many adults are maintained on 50–200 micrograms daily, guided by blood pressure lying and standing, ankle swelling, sodium and potassium levels and sometimes plasma renin. Salt intake also needs watching, and serum electrolytes should be checked periodically during long-term treatment.

Fludrocortisone acetate is licensed in the UK as a prescription-only medicine (POM). It is supplied mainly as generic 50 and 100 microgram tablets and as an oral solution; some versions must be kept in the fridge, while others are stored below 30°C, so follow the leaflet in your own pack. People with Addison's disease are advised to carry a steroid emergency card.

For Florinef and other fludrocortisone tablets, the SmPC lists hypersensitivity and systemic infection unless it is being treated with suitable anti-infective medicines. Because of its marked effect on sodium, use outside the licensed indications is not advised. Live vaccines should not be given to people on immunosuppressive corticosteroid doses. Extra care is needed with high blood pressure, heart failure, kidney problems, osteoporosis, glaucoma, diabetes, peptic ulcer and a history of tuberculosis or severe mood disorders. Contact with chickenpox or measles should be reported to a doctor promptly.

When Florinef is combined with diuretics, amphotericin B or other potassium-lowering medicines, there is a higher risk of low potassium, which in turn raises the risk of toxicity with digoxin. Enzyme inducers such as carbamazepine, phenytoin, barbiturates and rifampicin can speed up its clearance. Fludrocortisone may change the effect of warfarin, raise blood sugar in diabetes, oppose blood pressure medicines and add to the stomach risks of NSAIDs.

Most side effects come from too much salt-retaining activity: high blood pressure, swollen ankles, weight gain, headache and low potassium, which can cause muscle weakness or cramps. Heart failure is a rarer risk. Never stop Florinef suddenly; during vomiting, injury or serious illness, adrenal crisis is an emergency and needs 999 or A&E. Any change in dose is for your doctor or prescriber to decide.