betamethasone/fusidic acid

Action and Spectrum

Actions and Spectrum: 

betamethasone and fusidic acid are two different medications with distinct mechanisms of action and spectra of activity: 

betamethasone: 

Action:  

betamethasone is a corticosteroid medication that suppresses inflammation and immune responses. It belongs to the class of drugs known as glucocorticoids. betamethasone exerts its effects by binding to specific receptors (glucocorticoid receptors) in cells, which leads to the inhibition of various inflammatory mediators and immune responses. 

Spectrum:  

betamethasone is primarily used to treat various inflammatory and immune-mediated conditions, such as: 

Skin conditions like eczema, psoriasis, and dermatitis. 

Allergic reactions and hypersensitivity reactions. 

Inflammatory joint conditions like rheumatoid arthritis. 

Asthma and other respiratory conditions. 

Autoimmune diseases. 

fusidic Acid: 

Action: fusidic acid is an antibiotic that inhibits bacterial protein synthesis. It primarily targets and disrupts the function of bacterial ribosomes, inhibiting protein production in bacteria. 

Spectrum: fusidic acid is effective against Gram-positive bacteria, particularly Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus, MRSA). It is commonly used topically (in creams or ointments) to treat skin infections caused by susceptible bacteria, such as impetigo and localized infections. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Skin burning sensation 

Application site swelling/vesicles 

Pruritus 

Dry skin 

Eczema  

Rarely, erythema 

Hypersensitivity 

Contact dermatitis 

Urticaria  

Application site pain/irritation 

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution: 

Contraindication 

• Hypersensitivity: Do not use betamethasone if you have a known hypersensitivity or allergy to betamethasone or other corticosteroids. 
• Infections: betamethasone can suppress the immune system. It should be used with caution, or not at all, in the presence of active infections, especially systemic fungal, bacterial, or viral infections. 
• Glaucoma and Cataracts: Prolonged use of betamethasone near the eyes can increase the risk of developing glaucoma and cataracts. 
• Diabetes: Patients with diabetes should use betamethasone cautiously, as it can elevate blood glucose levels. 
• Osteoporosis: Prolonged use can lead to bone loss, so it should be used cautiously in individuals with osteoporosis. 
• Pregnancy and Breastfeeding: Using betamethasone during pregnancy and breastfeeding should be carefully discussed with a healthcare provider. 

fusidic Acid: 

• Hypersensitivity: Do not use fusidic acid if you have a known hypersensitivity or allergy to fusidic acid or related antibiotics. 
• Liver Dysfunction: The liver metabolizes fusidic acid, so it should be used cautiously in individuals with pre-existing liver conditions. 
• Pregnancy and Breastfeeding: The safety of fusidic acid during pregnancy and breastfeeding is not well-established, and its use should be discussed with a healthcare provider. 
• Kidney Dysfunction: Although rare, fusidic acid has been sometimes associated with kidney problems. 

Caution 

betamethasone: 

• Prolonged Use: Avoid prolonged or excessive use of betamethasone, especially on large areas of the skin. Extended use can lead to skin thinning, making the skin more vulnerable to irritation and other skin problems. 
• Tapering: If you have been using betamethasone for an extended period and need to stop treatment, it’s generally advisable to taper the dose gradually under the supervision of a healthcare provider. Abruptly discontinuing corticosteroids can lead to a rebound effect, where the original condition may worsen. 
• Children: Use betamethasone with caution in children, as their skin is more sensitive and may absorb the medication more readily. 
• Topical Steroid Addiction/Withdrawal: Prolonged use of topical corticosteroids, including betamethasone, can sometimes lead to a condition known as topical steroid addiction or withdrawal. This may result in worsened skin symptoms when discontinuing the medication. 
• Avoid Contact with Eyes: Avoid contact with betamethasone cream or ointment in or around the eyes, as it can lead to eye problems like glaucoma and cataracts. 

fusidic Acid: 

• Resistance: The prolonged or inappropriate use of fusidic acid can lead to the development of antibiotic resistance. It should be reserved for treating bacterial infections when other antibiotics are unsuitable. 
• Not for Systemic Infections: fusidic acid is primarily used topically for skin infections. It should not be used to treat systemic infections or infections in other parts of the body. 
• Superinfections: Be cautious about the possibility of superinfections (new infections that occur during or after treatment) when using fusidic acid, significantly if the treatment is prolonged. If a new infection occurs, consult a healthcare provider. 
• Monitoring: If you have liver or kidney dysfunction, your healthcare provider may monitor you closely while using fusidic acid, as it is metabolized by the liver and excreted by the kidneys. 

Pregnancy / Lactation

Pregnancy consideration:  

US FDA pregnancy category: Not assigned 

Lactation:   

Excreted into human milk: Not known. 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence, these categories of drugs need to be avoided by pregnant women.    
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

betamethasone is a synthetic corticosteroid with potent anti-inflammatory and immunosuppressive properties. It exerts its pharmacological effects by binding to intracellular glucocorticoid receptors, resulting in the suppression of inflammatory responses, inhibition of immune cell activation, and the downregulation of multiple pro-inflammatory genes. betamethasone alleviates various inflammatory conditions, including skin disorders like eczema and psoriasis, and manages allergic reactions and autoimmune diseases.

In contrast, fusidic acid is an antibiotic that interferes with bacterial protein synthesis by targeting ribosomes. It primarily targets Gram-positive bacteria, such as Staphylococcus aureus, including methicillin-resistant strains. fusidic acid is applied topically to treat bacterial skin infections, including impetigo and infected wounds, offering bacteriostatic activity against susceptible pathogens. 

Pharmacodynamics: 

Mechanism of action: 

betamethasone: 

Mechanism of Action: betamethasone is a synthetic corticosteroid with potent anti-inflammatory and immunosuppressive properties. Its mechanism of action is primarily related to its interaction with glucocorticoid receptors inside cells. When betamethasone binds to these receptors, several pharmacological effects occur: 

Suppression of Inflammation: betamethasone suppresses the production and release of inflammatory mediators, like the prostaglandins and leukotrienes, leading to a reduction in inflammation and associated symptoms like redness, swelling, and pain. 

Immune System Modulation: It dampens the activity of the immune system by inhibiting the activation of immune cells (like T-cells and macrophages), which helps manage immune-related disorders. 

Inhibition of Allergic Reactions: betamethasone can alleviate allergic reactions by decreasing the release of histamine and other allergic mediators. 

Regulation of Gene Expression: It influences the expression of various genes involved in inflammation and also immune responses, resulting in the overall suppression of these processes. 

betamethasone is often used topically for skin conditions, inhaled for respiratory conditions, and systemically for various inflammatory and autoimmune disorders. 

fusidic Acid: 

Mechanism of Action: fusidic acid is an antibiotic with a unique mechanism of action that targets bacterial protein synthesis. Its primary target is the ribosome, a cellular structure essential for protein production in bacteria. fusidic acid inhibits the elongation of the bacterial protein chain by preventing the release of elongation factor G (EF-G) from the ribosome. This inhibition of the ribosomal function leads to the following effects: 

Bacteriostatic Activity: fusidic acid primarily has bacteriostatic activity, inhibiting the growth and reproduction of susceptible bacteria rather than directly killing them. 

Blockage of Protein Synthesis: By blocking protein synthesis, fusidic acid disrupts the bacterial cell’s ability to produce essential proteins, ultimately leading to cell death. 

Gram-Positive Bacteria: fusidic acid is particularly effective against Gram-positive bacteria, including Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA), which are commonly implicated in skin infections. 

Pharmacokinetics: 

Absorption 

When applied to the skin, betamethasone can be absorbed via the skin barrier and into the bloodstream, mainly if used on thin or sensitive skin areas. The extent of absorption can vary based on factors such as the formulation and the condition of the skin. 

When applied to the skin, fusidic acid is absorbed locally into the underlying tissues, where it can exert its antibacterial effects. Systemic absorption of fusidic acid from topical application is generally low. 

Distribution 

Once absorbed, betamethasone is distributed throughout the body, including to various tissues. It binds to plasma proteins, like albumin, which can affect its distribution in the bloodstream. 

fusidic acid is distributed to various tissues within the body; however, its use is predominantly topical, so systemic distribution is limited. 

Metabolism 

betamethasone is primarily metabolized by the liver through a process known as hepatic metabolism. It undergoes extensive metabolism, primarily by enzymatic processes, to form inactive metabolites that are eventually excreted from the body. 

fusidic acid undergoes minimal metabolism in the liver. It is primarily excreted unchanged in the bile. 

Elimination and Excretion 

The metabolites of betamethasone are excreted mainly through the kidneys as well as through feces via bile. The excretion process removes the metabolites from the body. 

The excretion of fusidic acid occurs primarily through the bile and feces. It is eliminated from the body in its unchanged form. 

Adminstartion

Administration: 

betamethasone and fusidic acid can be administered separately or, in some cases, as a combination product for specific skin conditions.  

betamethasone: 

Topical Administration:

betamethasone is most commonly administered topically (applied to the skin) as creams, ointments, lotions, or gels.  

Wash your hands thoroughly before and after application. 

Apply a thin layer of betamethasone to the affected area and gently rub it in until it’s absorbed. 

Rewash your hands after applying unless you are treating your hands. 

Avoid Eye and Mucous Membrane Contact: Avoid contact with the eyes, mouth, and also other mucous membranes when applying betamethasone. It should not be used on the face unless directed by your healthcare provider. 

Frequency: Follow your healthcare provider’s instructions regarding how often to apply betamethasone. Typically, it is applied once or twice a day. 

Duration: Use betamethasone for the duration prescribed by your healthcare provider. Do not discontinue abruptly, especially if you have been using it for an extended period, as this can lead to a rebound effect. 

fusidic Acid: 

Topical Administration: fusidic acid is primarily administered topically for skin infections. Follow these steps for topical administration: 

Apply a thin fusidic acid ointment or cream to the infected area. 

Gently rub it in until it’s absorbed. 

Wash your hands thoroughly before and after application. 

Frequency: Typically, fusidic acid is applied two to three times a day. Follow your healthcare provider’s instructions for the specific frequency. 

Duration: Use fusidic acid for the entire duration prescribed by your healthcare provider, even if the infection appears to have cleared. Stopping treatment prematurely can lead to incomplete eradication of the infection and possible recurrence. 

Combination Products (betamethasone and fusidic Acid): 

If you are prescribed a combination product that contains both betamethasone and fusidic acid, follow the specific instructions provided by the healthcare provider and the medication’s packaging. These products are typically used for short-term treatment of skin conditions that involve both inflammation and bacterial infection. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: betamethasone/fusidic acid 

Why do we use betamethasone/fusidic acid? 

There are combination products that contain both betamethasone and fusidic acid. These are typically used for skin conditions involving inflammation and bacterial infection. Common uses for these combination products include: 

• Infected Eczema: Eczema that becomes secondarily infected with bacteria can be treated with betamethasone and fusidic acid combination creams or ointments. 
• Impetigo: A bacterial skin infection often treated with a combination of these medications. 
• Dermatitis with Infection: Conditions like contact dermatitis that develop bacterial infections may benefit from this combination.