Fludrocortisone

Fludrocortisone (中文: 氟可的松)is a steroid with potent mineralocorticoid activity. It is used to treat:

• Adrenocortical insufficiency
• Postural hypotension
• Adrenogenital syndrome

Pronunciation

Fludrocortisone 100mcg

Drug name

Generic Name	HA Code	Legal Classification
Fludrocortisone Acetate Tablet 100mcg	FLUD01	P1S1S3

Mechanism of Action

Fludrocortisone is a corticosteroid with glucocorticoid and highly potent mineralocorticoid activity.

Dosage

Fludrocortisone is used, usually with hydrocortisone, for replacement therapy in adrenocortical insufficiency.

Replacement therapy in adrenal insufficiency	Oral: 50-300 micrograms daily
Severe orthostatic hypotension	Oral: 50-300 micrograms daily

It is also used ear drops in concentration of 0.1%.

Side Effects

Fludrocortisone acetate has glucocorticoid actions about 10 times as potent as hydrocortisone and mineralocorticoid effects more than 100 times as potent. Adverse effects are mainly those due to mineralocorticoid activity:

• Sodium and water retention
• Swelling due to fluid retention (oedema)
• Hypertension
• Increased excretion of potassium leading to hypokalaemia
• Heart failure may be induced in susceptible patients

Other side-effects include:

Steroid-induced diabetes	Raised blood sugar level
Osteoporosis, muscle wasting and weakness	Particularly danger in the elderly, as it can result in osteoporotic fractures for example of the hip or vertebrae
Susceptibility to infection
Disturbances of the gut	Indigestion, peptic ulcer, distension of the abdomen
Suppression of growth in children
Endocrine side effects	Menstrual irregularities , hirsutism (increased hair growth), weight gain
Neuropsychiatric side effects	Aggravation of schizophrenia, aggravation of epilepsy, insomnia, irritability, depression
Dermatological side effects	Easy bruising, impaired wound healing, thinning of skin and stretch marks
Ophthalmic side effects	Glaucoma, partial loss of vision due to opacity in the lens of the eye (cataracts)

Pharmacokinetics

Fludrocortisone is readily absorbed from the gastrointestinal tract.

The plasma half-life is about 3.5 hours, but fludrocortisone has a more prolonged biological half-life of 18 to 36 hours.

Drug Management

Monitoring

• Elderly (close supervision required particularly on long-term treatment)
• Frequent monitoring required if history of tuberculosis (or X-ray changes)
• Blood sugar level, blood pressure, mood change
• Monitoring of the fluid intake and output, and daily weight records may give early warning of fluid retention
• Sodium intake may need to be reduced and calcium and potassium supplements may be necessary
• Back pain may signify osteoporosis
• Plasma renin, sodium, and potassium is checked through blood tests to verify that the correct dosage is reached

Drug interaction

Interactions do not generally apply to steroid used for topical action including inhalation, unless specified.

Drugs given with steroid	Potential adverse drug interactions
NSAIDs	Increased risk of gastro-intestinal bleeding
Rifampicin	Accelerate metabolism of fludrocortisone so reduce its effects
Antidiabetics	Antagonize hypoglycemic effect, so may need to increase antidiabetic dosage
Antiepileptics such as carbamazepine, phenobarbitone, phenytoin	Accelerate metabolism of fludrocortisone so reduce its effects
Antifungal e.g. amphotericin	Increased risk of hypokalaemia
Antiviral e.g ritonavir	Increase plasma concentration of steroid – increased risk of adrenal suppression
Digoxin	Increased risk of hypokalaemia
Diuretics e.g. frusemide, hydrochlorothiazide	Antagonize diuretic effect; increased risk of hypokalaemia
Oral contraceptive (oestrogens)	Increase plasma concentration of steroid
Theophylline	Increased risk of hypokalaemia

Caution

• Osteoporosis (post-menopausal women at special risk)
• Recent myocardial infarction, congestive heart failure
• Glaucoma (including family history)
• Ocular herpes simplex – risk of corneal perforation
• Psychiatric disorders (particularly if history of steroid-induced psychosis)
• Epilepsy
• Peptic ulcer
• Hypothyroidism
• Ulcerative colitis
• Diverticulitis
• Thromboembolic disorders

Contraindication

• Acute infections
• Patients with active or doubtfully quiescent tuberculosis
• Concurrent treatment live virus vaccines for at least 3 months afterwards

Hepatic impairment

When steroids are administered orally or parenterally, the plasma-drug concentration may be increased in patients with hepatic impairment. The patient should be monitored closely.

Renal impairment

Should be used with caution in patients with renal impairment.

Pregnancy

It is not yet clear if use of fludrocortisone during pregnancy is safe for the fetus.

Note

Prolonged use of steroid	Advice to patient
Increase susceptibility to infection	Avoid contact with people who have chickenpox, shingles, or measles.
Suppresses the endogenous secretion of corticotrophin by the anterior pituitary, resulting the adrenal cortex becomes atrophied. If given for more than 3 weeks, treatment MUST be stopped gradually.	Patient must mention the course of steroid when receiving treatment for intercurrent illnesses or going through trauma such as surgery.

FAQ

How should I take the tablet?

The tablet MUST be taken with or after food to help reduce GI side-effects.

What should I avoid while taking?

Avoid abruptly discontinue the medication. Should not be taken with NSAIDs.

What happen if I overdose?

Contact your primary care doctor. If emergency situation, call 999

What happen if I miss a dose?

Take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. IV, IM and IA: administered by professionals