PHENASEN 10 mg/10 ml

Indications

• Acute promyelocytic leukemia (APL)
• Arsenic poisoning
• Chronic arsenic exposure

Dosage

Children: For acute promyelocytic leukemia in children, dosing should be determined based on individual weight and clinical response, and it is advisable to refer to the BNF for Children for specific

Adults: For acute promyelocytic leukemia, arsenic trioxide is typically administered intravenously at a dose of 0.15 mg/kg per day until complete remission is achieved, followed by a consolidation phase.

Mechanism of action

Arsenic trioxide induces apoptosis in cancer cells, particularly in acute promyelocytic leukemia (APL) cells, by promoting the degradation of the promyelocytic leukemia-retinoic acid receptor alpha (PML-RARA) fusion protein. This process leads to cellular differentiation and death. It is also known to generate reactive oxygen species, which contribute to its cytotoxic effects.

Pharmacodynamics

Arsenic exhibits dose-dependent effects which vary based on its chemical form and exposure route. Its cytotoxic activity is primarily linked to its ability to induce oxidative stress, alter cellular signaling pathways, and interfere with DNA repair mechanisms. Therapeutic doses of arsenic trioxide can lead to the differentiation of APL cells, while higher doses may result in significant toxicity.

Pharmacokinetics

Arsenic is absorbed through the gastrointestinal tract, lungs, and skin, with the extent of absorption depending on the chemical form. It is distributed throughout the body, accumulating in the liver, kidneys, and skin. The metabolism of arsenic involves methylation processes, leading to the formation of various metabolites. Elimination occurs primarily via urine, with a half-life that can vary based on the arsenic species and individual patient factors.

Adverse effects

• Nausea
• Vomiting
• Abdominal pain
• Diarrhea
• Dermatitis
• Peripheral neuropathy
• Hematological abnormalities
• Cardiovascular effects
• Cancer risk with chronic exposure

Precautions

• Use with caution in patients with hepatic or renal impairment
• Monitor for signs of toxicity in prolonged use
• Assess for potential exposure risks in occupational settings

Pregnancy

Arsenic is classified as a teratogen and may pose risks during pregnancy, including developmental harm to the fetus.

Breast-feeding

It is advisable to avoid breastfeeding during arsenic treatment due to potential excretion in breast milk.

Storage

Store in a cool, dry place, away from direct light and moisture.

Indications

• Acute promyelocytic leukemia (APL)
• Refractory acute myeloid leukemia (AML)
• Other malignancies as determined by clinical protocol

Dosage

Children: Refer to the BNF for Children for appropriate dosing information based on age and weight.

Adults: Dosing should be guided by clinical protocols and specific treatment guidelines. Refer to established treatment regimens for detailed dosing information.

Mechanism of action

Trioxide acts by inducing apoptosis in cancer cells, primarily through the activation of caspases and the modulation of signaling pathways involved in cell survival and death. It alters gene expression and promotes differentiation of promyelocytic cells into mature myeloid cells, leading to the reduction of leukemic cells. Arsenic trioxide also affects multiple pathways including the inhibition of the PI3K/AKT pathway, thus promoting programmed cell death.

Pharmacodynamics

The pharmacodynamic effects of trioxide include its ability to induce cell cycle arrest and promote differentiation in malignant cells. Its action leads to the downregulation of anti-apoptotic proteins and upregulation of pro-apoptotic factors, enhancing the sensitivity of leukemic cells to apoptosis. The drug displays a concentration-dependent effect on cell viability, and its efficacy is influenced by the cellular context and genetic background of the malignancy.

Pharmacokinetics

Trioxide is administered intravenously and has a volume of distribution that suggests extensive tissue binding. It undergoes hepatic metabolism, primarily through oxidation and conjugation, with renal excretion of metabolites. The plasma half-life varies depending on the dosing regimen and patient characteristics. Steady-state concentrations are achieved after several doses, and therapeutic drug monitoring may be beneficial to optimize treatment and minimize toxicity.

Pregnancy

Trioxide should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult a healthcare provider for further guidance.

Breast-feeding

It is not known whether trioxide is excreted in human milk. Caution is advised when administering to breastfeeding women.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.