Dimercaprol, also known as British Anti-Lewisite (BAL), has specific dosing instructions and considerations due to its use in treating heavy metal poisoning, particularly arsenic, mercury, gold, and lead.
- Dose and Dosage: The typical dosage of dimercaprol for adults is 3-5 mg/kg every 4 hours for up to 10 doses, followed by a reduced frequency of administration. Dosage may vary based on the severity of poisoning and individual patient factors. Pediatric dosing is typically lower and based on weight.
- Frequency: Dimercaprol is usually administered every 4 hours initially, with the frequency reduced after the first 10 doses.
- Route of Administration (ROA): Dimercaprol is administered intramuscularly (IM).
- Mechanism of Action (MOA): Dimercaprol chelates with heavy metals, forming stable complexes that can be excreted via the kidneys, thereby reducing the toxic effects of heavy metal poisoning.
- Pharmacokinetics (PK): Dimercaprol is rapidly absorbed after IM injection and distributed widely in the body. It undergoes hepatic metabolism and is primarily excreted via the kidneys.
- Pathophysiology: Heavy metal poisoning occurs when toxic levels of heavy metals accumulate in the body, leading to tissue damage and organ dysfunction.
- Indications: Dimercaprol is indicated for the treatment of acute poisoning by arsenic, gold, mercury, and lead.
- Contraindications: Dimercaprol is contraindicated in patients with known hypersensitivity to the drug and in those with severe renal impairment.
- Drug Interactions: Dimercaprol may interact with other medications, particularly those containing heavy metals. It may also interact with drugs that affect renal function or hepatic metabolism.
- Precautions: Special precautions should be taken when administering dimercaprol to patients with impaired renal function or hepatic impairment. Monitoring of renal and hepatic function is recommended during treatment.
- Monitoring and Laboratory Tests: Monitoring of renal and hepatic function, as well as blood pressure, is recommended during treatment with dimercaprol. Laboratory tests may include serum electrolytes, creatinine, liver enzymes, and blood urea nitrogen.
It’s crucial to follow the specific dosing instructions provided by a healthcare professional when using dimercaprol, as improper dosing or administration can lead to adverse effects or inadequate treatment of heavy metal poisoning.
Medication Information and Guidelines
Dimercaprol (BAL)
- Purpose: Dimercaprol is used to treat acute poisoning by heavy metals such as arsenic, gold, mercury, and lead. It works by forming stable complexes with heavy metals, which are then excreted from the body, reducing their toxic effects.
- Usage: Dimercaprol is typically administered intramuscularly (IM) every 4 hours initially, with the frequency reduced after the first 10 doses. The dosage may vary based on the severity of poisoning and individual patient factors.
- Other Uses: Dimercaprol is not typically used for other conditions besides heavy metal poisoning.
- Precautions: Patients should be monitored closely for signs of hypersensitivity reactions. Dimercaprol may interact with other medications, particularly those containing heavy metals. Special caution is needed in patients with impaired renal or hepatic function.
- Dietary Changes: There are no specific dietary restrictions associated with dimercaprol use.
- Missed Dose: If a dose is missed, it should be taken as soon as remembered. However, if it is almost time for the next dose, the missed dose should be skipped, and the regular dosing schedule resumed. It is essential not to double the dose to catch up.
- Side Effects: Common side effects may include pain at the injection site, nausea, vomiting, headache, dizziness, and a garlic-like taste in the mouth. Serious side effects such as anaphylaxis or severe hypersensitivity reactions are rare but possible.
- Storage and Disposal: Dimercaprol should be stored at room temperature away from moisture and heat. It should be kept out of reach of children. Unused or expired medication should be disposed of properly according to local guidelines.
- Overdose/Emergency: In case of an overdose or emergency situation, immediate medical attention should be sought. Symptoms of overdose may include severe allergic reactions, difficulty breathing, chest pain, and loss of consciousness.