HEMAX 4,000 IU FREEZE DRIED POWDER FOR INJECTION

Indications

• Hypertension
• Benign prostatic hyperplasia
• Urinary retention related to prostate enlargement

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines in the paediatric population.

Adults: Refer to the BNF for specific dosing recommendations based on individual clinical scenarios.

Mechanism of action

Alpha acts by selectively blocking alpha-1 adrenergic receptors, which are responsible for mediating vasoconstriction in blood vessels. By inhibiting these receptors, alpha promotes vasodilation, leading to a decrease in peripheral vascular resistance and subsequently lowering blood pressure. Additionally, this action can help alleviate urinary symptoms associated with an enlarged prostate.

Pharmacodynamics

The pharmacodynamics of alpha involve its competitive antagonism at alpha-1 adrenergic receptors, resulting in decreased vasoconstriction and increased blood flow. This mechanism is beneficial in conditions characterized by high blood pressure and urinary retention due to prostatic enlargement. The onset of action typically occurs within hours, with peak effects observed within a few days of consistent dosing.

Pharmacokinetics

Alpha is absorbed well from the gastrointestinal tract, with peak plasma concentrations achieved within 1-3 hours post-administration. The drug undergoes hepatic metabolism, primarily via cytochrome P450 enzymes, resulting in active and inactive metabolites. The elimination half-life varies, but it generally is around 6-12 hours, allowing for once-daily dosing in many cases. Renal excretion is a significant route for its metabolites, necessitating caution in patients with renal impairment.

Interactions

• maois, irreversible + alpha blockers: Severe (increases effects)
• ribociclib + alpha blockers: Severe (increases exposure)
• cobicistat + alpha blockers: Moderate (increases exposure)
• idelalisib + alpha blockers: Moderate (increases exposure)
• dronedarone + alpha blockers: Unknown (increases exposure)
• antifungals, azoles + alpha blockers: Unknown (increases exposure)
• crizotinib + alpha blockers: Unknown (increases exposure)
• imatinib + alpha blockers: Unknown (increases exposure)
• letermovir + alpha blockers: Unknown (increases exposure)
• clarithromycin + alpha blockers: Unknown (increases exposure)

Indications

• Anemia of chronic kidney disease
• Anemia associated with cancer chemotherapy
• Anemia in patients undergoing major surgery
• Anemia in patients with HIV receiving zidovudine

Dosage

Children: Refer to the BNF for Children for specific pediatric dosing information.

Adults: Refer to the BNF for specific dosing guidelines based on the condition being treated.

Mechanism of action

Epoetin binds to the erythropoietin receptor on erythroid progenitor cells in the bone marrow, promoting their differentiation and proliferation. This action stimulates erythropoiesis, leading to increased production of RBCs. Additionally, it enhances the survival of erythroid progenitor cells and promotes the release of reticulocytes into the bloodstream, ultimately leading to an increase in hemoglobin levels.

Pharmacodynamics

Epoetin exhibits dose-dependent effects on erythropoiesis. Its activity results in increased hemoglobin concentration and hematocrit levels. The onset of action is generally observed within a few days, with peak effects typically seen within 1 to 2 weeks of administration. Long-term use may lead to increased RBC mass and improved oxygen delivery to tissues.

Pharmacokinetics

Epoetin is administered via subcutaneous or intravenous routes. It has a half-life of approximately 4 to 13 hours, depending on the formulation and route of administration. The drug is primarily eliminated through the kidneys, with a significant portion undergoing metabolic degradation. The pharmacokinetics may be influenced by factors such as renal function and patient-specific characteristics.

Contra-indications

• Uncontrolled hypertension
• Pure red cell aplasia
• Hypersensitivity to epoetin or any of its components

Adverse effects

• Hypertension
• Headache
• Fatigue
• Nausea
• Diarrhea
• Injection site reactions
• Thrombotic events (e.g., stroke, myocardial infarction)

Interactions

• Antihypertensive agents may require dose adjustments due to the potential for increased blood pressure
• Iron supplements may be used concurrently; ensure adequate iron stores for optimal erythropoiesis

Precautions

• Monitor hemoglobin levels regularly to avoid excessive increases
• Use with caution in patients with a history of cardiovascular disease
• Assess iron status before and during treatment

Pregnancy

Epoetin may be used during pregnancy if the benefits outweigh the risks, as it is classified as category C.

Breast-feeding

Epoetin is excreted in breast milk; caution is advised when administered to nursing mothers.

Storage

Store in the refrigerator (2°C to 8°C), do not freeze. Keep protected from light.

Formulations

• Epoetin alfa injectable solution
• Epoetin beta injectable solution