Hydrocortisone

BRAND NAMES

• Cortef (oral tablets)

• Solu-Cortef (injectable form)

• Hydrocortone

• Cortifoam (rectal foam)

• Anusol-HC (topical/rectal combination products in some regions)

MECHANISM OF ACTION

Hydrocortisone is a glucocorticoid that works by binding to intracellular receptors and altering gene expression. This reduces the production of inflammatory chemicals like prostaglandins and cytokines, leading to decreased inflammation, immune response, and allergic reactions.

PHARMACOKINETICS

Absorption

Hydrocortisone is well absorbed after oral administration, reaching peak blood levels in about 1 to 2 hours. It is also absorbed through the skin, especially when applied to inflamed areas, and then binds to plasma proteins in the bloodstream for distribution.

Distribution

Hydrocortisone is widely distributed throughout the body after absorption, with a volume of distribution of approximately 0.4–0.7 L/kg. It is extensively bound to plasma proteins, mainly corticosteroid-binding globulin (CBG) and albumin, with only the free fraction being biologically active and able to enter tissues.

Metabolism

Hydrocortisone is primarily metabolized in the liver by reduction and conjugation reactions. It is converted into inactive metabolites such as tetrahydrocortisone and tetrahydrocortisol, mainly through the action of enzymes like 5α- and 5β-reductase followed by hepatic conjugation with glucuronic acid and sulfate.

Elimination

Hydrocortisone is eliminated mainly through the kidneys as inactive metabolites after hepatic metabolism. Only a very small amount of unchanged drug is excreted in urine, and the elimination half-life is typically about 1.5 to 2 hours.

PHARMACODYNAMICS

Hydrocortisone binds to glucocorticoid receptors and changes gene expression, leading to reduced inflammation and immune activity. It also affects metabolism by increasing glucose production and helping the body respond to stress.

ADMINISTRATION

Hydrocortisone can be administered orally, intravenously, intramuscularly, topically, rectally, or as a topical cream or ointment, depending on the condition being treated. Oral and IV forms are commonly used for adrenal insufficiency and severe inflammation, while topical forms are used for skin conditions like eczema and dermatitis.

DOSAGE AND STRENGTH

Hydrocortisone is available in multiple strengths depending on the formulation and route of administration. Oral tablets are commonly available in strengths such as 5 mg, 10 mg, and 20 mg. For injectable use, hydrocortisone sodium succinate is typically supplied in strengths like 100 mg and 500 mg vials for emergency or hospital settings. Topical preparations vary widely, usually ranging from 0.5% to 2.5% creams, ointments, or lotions depending on the severity of the skin condition being treated. Dosage is individualized based on the patient’s condition, age, and clinical response.

DRUG INTERACTIONS

Hydrocortisone may interact with other drugs such as enzyme inducers like rifampicin and phenytoin, which reduce its effect, while ketoconazole can increase its levels. It can also reduce the effect of antidiabetic drugs and increase the risk of side effects when used with diuretics or NSAIDs.

FOOD INTERACTIONS

Hydrocortisone has minimal food interactions, but it is usually taken with food to reduce stomach upset. High-salt diets may increase fluid retention, and alcohol should be avoided as it can raise the risk of stomach irritation and ulcers.

CONTRAINDICATIONS

Hydrocortisone is contraindicated in patients with known hypersensitivity to the drug or its components. It should not be used in untreated systemic fungal infections. Caution is also required in conditions like active peptic ulcer disease, severe infections, and uncontrolled diabetes, where corticosteroids may worsen the condition.

SIDE EFFECTS

• Increased appetite

• Weight gain

• Fluid retention

• Mood changes

• Hypertension

• Hyperglycemia

OVER DOSE

• Cushingoid symptoms (moon face, weight gain)

• Severe fluid retention and edema

• High blood pressure (hypertension)

• High blood sugar (hyperglycemia)

• Electrolyte imbalance (low potassium)

TOXICITY

Hydrocortisone toxicity can lead to Cushing’s syndrome–like effects such as weight gain, moon face, and fluid retention. It may also cause adrenal suppression, high blood pressure, high blood sugar, low potassium, increased risk of infections, muscle weakness, and mood or psychiatric changes, especially with long-term or high-dose use.