Immunosuppressants

Immunosuppressants are key medications in preventing organ rejection after transplantation and in managing autoimmune disorders. They function by suppressing the activity of the immune system. They act to reduce the immune system’s intensity, preventing excessive reactions. These drugs are vital in conditions where the body’s immune system mistakenly targets its own tissues. Cyclosporine is a frequently prescribed example of an immunosuppressant.

1. T- and B-cell Suppressors

T- and B-cell Suppressors: These agents work by decreasing the activity of T and B lymphocytes. This action diminishes the immune system’s capacity to attack transplanted organs or the body’s own tissues in autoimmune conditions.

Therapeutic Action: These medications function by inhibiting the multiplication and activity of T and B lymphocytes, which is crucial for preventing transplant rejection and managing autoimmune diseases.

Pharmacokinetics: T- and B-cell suppressors are typically well-absorbed following oral or intravenous administration. Metabolism occurs in the liver, and excretion is mainly through the kidneys.

Contraindications:

• Known allergy to the drug or its components.

• Pregnancy and breastfeeding (due to potential harm to the fetus or infant).

• Kidney or liver dysfunction.

• Ongoing infections or diagnosed cancers.

2. Interleukin-Receptor Antagonist

2. Interleukin-Receptor Antagonists: This category of drugs functions by blocking the action of interleukins, which are vital signaling molecules in inflammation and immune responses.

Therapeutic Action: Interleukin-receptor antagonists work by preventing interleukins from binding to their receptors. This action leads to a reduction in inflammation and tissue damage.

Pharmacokinetics: Anakinra is given via subcutaneous injection and attains maximum blood levels within a few hours. Liver metabolism and primarily urinary excretion are the routes of elimination.

Contraindications:

• Allergies to anakinra or products made using E. coli.

• Pregnancy and breastfeeding (due to potential drug transfer to the baby).

• Kidney dysfunction, existing immunosuppression, or active infections.

3. Monoclonal Antibodies

3. Monoclonal Antibodies: Monoclonal antibodies are manufactured in the lab and are designed to imitate the immune system’s ability to combat pathogens like viruses. They are highly targeted, acting like “guided missiles” of the immune system. These antibodies are engineered to precisely target and attack specific cells or molecules. They are used in the treatment of cancer, autoimmune conditions, and infections. They function like a precise sniper team, focusing on specific targets while sparing the rest of the immune system.

Monoclonal antibodies include adalimumab (Humira), alemtuzumab (Campath), basiliximab (Simulect).

Indications:

• Prevention of renal transplant rejection

• Treatment of B-cell chronic lymphocytic leukemia

• Reduction of the signs and symptoms of Crohn disease

• Treatment of paroxysmal nocturnal hemoglobinuria, to reduce haemolysis.

• Treatment of B-cell non-Hodgkin lymphoma in conjunction with rituximab.

• Treatment of asthma with a very strong allergic component and seasonal allergic rhinitis not occasionally controlled by common medicine.

• Prevention of serious RSV (Respiratory syncytial virus) infection in high-risk children.

• Treatment of metastatic breast cancer.

• Treatment of psoriasis

Therapeutic Action: Monoclonal antibodies selectively target and neutralize pathogens or inflammatory molecules, resulting in focused immune suppression.

Pharmacokinetics: These medications are typically administered intravenously. Their half-life varies depending on the specific monoclonal antibody. Metabolism and excretion occur via the reticuloendothelial system.

Contraindications:

• Known allergy to the monoclonal antibody or murine-derived products.

• Fluid overload.

• Use with caution in patients with fever; manage fever before starting treatment.