Why is Prednisone prescribed?
Prednisone, a steroid drug, is used to reduce inflammation and alleviate symptoms in a variety of disorders, including rheumatoid arthritis and severe cases of asthma. It may be given to treat primary or secondary adrenal cortex insufficiency (lack of sufficient adrenal hormone in the body). It is used in treating all of the following:

Abnormal adrenal gland development
Allergic conditions (severe)
Blood disorders
Certain cancers (along with other drugs)
Diseases of the connective tissue including systemic lupus erythematosus
Eye diseases of various kinds
Flare-ups of multiple sclerosis
Fluid retention due to "nephrotic syndrome" (a condition in which damage to the kidneys causes protein to be lost in the urine)
Lung diseases, including tuberculosis
Meningitis (inflamed membranes around the brain)
Prevention of organ rejection
Rheumatoid arthritis and related disorders
Severe flare-ups of ulcerative colitis or enteritis (inflammation of the intestines)
Skin diseases
Thyroid gland inflammation
Trichinosis (with complications)
Most important fact about Prednisone
Prednisone lowers your resistance to infections and can make them harder to treat. Prednisone may also mask some of the signs of an infection, making it difficult for your doctor to diagnose the actual problem.
How should you take Prednisone?
Take prednisone exactly as prescribed. Dosages are kept to an absolute minimum.
If you need long-term prednisone treatment, your doctor may prescribe alternate-day therapy, in which you take the medication only every other morning. The "resting day" gives your adrenal glands a chance to produce some hormone naturally so they will not lose the ability.
If you have been taking prednisone for a period of time, you will probably need an increased dosage of the medication before, during, and after any stressful situation. Always consult your doctor if you are anticipating stress and think you may need a temporary dosage increase.
When stopping prednisone treatment, tapering off is better than quitting abruptly. Your doctor will probably have you decrease the dosage very gradually over a period of days or weeks.
You should take prednisone with food to avoid stomach upset.
If you are on alternate-day therapy or have been prescribed a single daily dose, take prednisone in the morning with breakfast (about 8 a.m.). If you have been prescribed several doses per day, take them at evenly spaced intervals around the clock.
Patients on long-term Prednisone therapy should wear or carry identification.
--If you miss a dose...
If you take your dose once a day, take it as soon as you remember. If you don't remember until the next day, skip the one you missed.
If you take several doses a day, take the forgotten dose as soon as you remember and then go back to your regular schedule. If you don't remember until your next dose, double the dose you take.
If you take your dose every other day, and you remember it the same morning, take it as soon as you remember, then go back to your regular schedule. If you don't remember until the afternoon, do not take a dose until the following morning, then skip a day.
--Storage instructions...
Store at room temperature.
What side effects may occur?
Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking prednisone.
Prednisone may cause euphoria, insomnia, mood changes, personality changes, psychotic behavior, or severe depression. It may worsen any existing emotional instability.
At a high dosage, prednisone may cause fluid retention and high blood pressure. If this happens, you may need a low-salt diet and a potassium supplement.
With prolonged prednisone treatment, eye problems may develop (e.g., a viral or fungal eye infection, cataracts, or glaucoma).
If you take prednisone over the long term, the buildup of adrenal hormones in your body may cause a condition called Cushing's syndrome, marked by weight gain, a "moon-faced" appearance, thin, fragile skin, muscle weakness, brittle bones, and purplish stripe marks on the skin. Women are more vulnerable to this problem than men. Alternate-day therapy may help prevent its development.
Why should Prednisone not be prescribed?
Do not take prednisone if you have ever had an allergic reaction to it.
You should not be treated with prednisone if you have a body-wide fungus infection, such as candidiasis or cryptococcosis.
Special warnings about Prednisone
Do not get a smallpox vaccination or any other immunization while you are taking prednisone. The vaccination might not "take," and could do harm to the nervous system.
Prednisone may reactivate a dormant case of tuberculosis. If you have inactive TB and must take prednisone for an extended time, you should be given anti-TB medication as well.
If you have an underactive thyroid gland or cirrhosis of the liver, your doctor will probably need to prescribe prednisone for you at a lower-than-average dosage.
If you have an eye infection caused by the herpes simplex virus, prednisone should be used with great caution; there is a potential danger that the cornea will become perforated.
A few people taking prednisone develop Kaposi's sarcoma, a form of cancer; it may disappear when the drug is stopped.
Prednisone should also be taken with caution if you have any of the following conditions:

Diverticulitis or other disorder of the intestine
High blood pressure
Kidney disorder
Myasthenia gravis (a muscle-weakness disorder)
Osteoporosis (brittle bones)
Peptic ulcer
Ulcerative colitis (inflammation of the bowel)
Long-term treatment with prednisone may stunt growth. If Prednisone is given to a child, the youngster's growth should be monitored carefully.
Diseases such as chickenpox or measles can be very serious or even fatal in both children and adults who are taking Prednisone. Try to avoid exposure to these diseases.
Possible food and drug interactions when taking Prednisone
Prednisone may decrease your carbohydrate tolerance or activate a latent case of diabetes. If you are already taking insulin or oral medication for diabetes, make sure your doctor knows this; you may need an increased dosage while you are being treated with prednisone.
If you have a blood-clotting disorder caused by a vitamin K deficiency and are taking prednisone, check with your doctor before you use aspirin.
You may be at risk of convulsions if you take the immunosuppressant drug cyclosporine (Sandimmune) while being treated with prednisone.
If prednisone is taken with certain other drugs, the effects of either could be increased, decreased, or altered. Check with your doctor before combining prednisone with any of the following:

Amphotericin B (Fungizone)
Blood thinners such as Coumadin
Carbamazepine (Tegretol)
Estrogen drugs such as Premarin
Ketoconazole (Nizoral)
Oral contraceptives
Phenobarbital (Donnatal, others)
Phenytoin (Dilantin)
Potent diuretics such as Lasix
Rifampin (Rifadin)
Troleandomycin (Tao)
Special information if you are pregnant or breastfeeding
If you are pregnant or plan to become pregnant, inform your doctor immediately. Prednisone should be taken during pregnancy or while breastfeeding only if clearly needed and only if the benefit outweighs the potential risks to the child.
Recommended dosage
Dosage is determined by the condition being treated and your response to the drug. Typical starting doses can range from 5 milligrams to 60 milligrams a day. Once you respond to the drug, your doctor will lower the dose gradually to the minimum effective amount. For treatment of acute attacks of multiple sclerosis, doses of as much as 200 milligrams per day may be given for a week, followed by 80 mg every other day for a month.
Overdosage
Long-term high doses of prednisone may produce Cushing's syndrome (see "Side Effects" section). Although no specific information is available regarding short-term overdosage, any medication taken in excess can have serious consequences. If you suspect an overdose of prednisone, seek medical attention immediately.