Chloramphenicol – Dose, ROA, MOA, PK, PD, Indications & More

Dose and Dosage:

  • Chloramphenicol is typically prescribed in various formulations, including oral capsules, tablets, and liquid suspensions, as well as ophthalmic solutions and topical creams.
  • The dosage and frequency depend on the type and severity of the infection being treated, as well as the patient’s age, weight, and medical condition.
  • Dosages may vary widely, but typical doses range from 50 mg to 100 mg per kilogram of body weight per day, divided into multiple doses.

Route of Administration (ROA):

  • Chloramphenicol can be administered orally, topically, or intravenously (IV), depending on the type of infection and the formulation of the medication.

Mechanism of Action (MOA):

  • Chloramphenicol inhibits bacterial protein synthesis by binding to the bacterial ribosome’s 50S subunit, thereby preventing peptide bond formation and inhibiting bacterial growth.

Pharmacokinetics (PK):

  • Chloramphenicol is well-absorbed orally, with peak plasma concentrations reached within 1-3 hours after ingestion.
  • It is widely distributed throughout the body, including into cerebrospinal fluid, but it does not penetrate well into the central nervous system (CNS).
  • Chloramphenicol is metabolized in the liver and excreted primarily in the urine, with a half-life of approximately 1.5-3 hours in adults.

Pharmacodynamics (PD):

  • Chloramphenicol exhibits bacteriostatic activity against a broad spectrum of gram-positive and gram-negative bacteria, as well as some anaerobic bacteria.

Pathophysiology:

  • Chloramphenicol acts by inhibiting bacterial protein synthesis, which disrupts bacterial growth and replication.

Indications:

  • Chloramphenicol is used to treat various bacterial infections, including respiratory tract infections, meningitis, typhoid fever, rickettsial infections, and certain sexually transmitted infections.
  • It is also used as a topical treatment for eye infections and as a second-line agent for the treatment of certain skin infections.

Contraindications:

  • Contraindications include hypersensitivity to chloramphenicol or any component of the formulation, as well as a history of bone marrow suppression or blood dyscrasias associated with previous chloramphenicol therapy.

Drug Interactions:

  • Chloramphenicol may interact with other medications, such as warfarin, phenytoin, and rifampin, potentially altering their metabolism and efficacy. It is important to consult a healthcare provider or pharmacist before combining medications.

Monitoring and Laboratory Tests:

  • Patients receiving chloramphenicol therapy should undergo regular monitoring of complete blood counts (CBC) and liver function tests (LFTs) to detect potential hematologic and hepatic adverse effects.
  • Ophthalmic formulations may require monitoring of ocular symptoms and visual acuity during treatment.

Why is this medication prescribed?

Chloramphenicol is prescribed to treat various bacterial infections, including respiratory tract infections, meningitis, typhoid fever, rickettsial infections, and certain sexually transmitted infections. It is also used as a topical treatment for eye infections and as a second-line agent for certain skin infections.

How should this medicine be used?

The medication is typically administered orally, topically, or intravenously, depending on the type of infection and the formulation prescribed by the healthcare provider. Dosage and frequency are determined based on the severity of the infection, patient age, weight, and medical condition.

Other uses for this medicine

In addition to its primary use as an antibiotic, chloramphenicol is sometimes used off-label to treat other conditions, as determined by a healthcare provider.

What special precautions should I follow?

Special precautions include informing the healthcare provider of any allergies or adverse reactions to chloramphenicol or any related medications. Patients with a history of bone marrow suppression or blood dyscrasias associated with previous chloramphenicol therapy should also inform their healthcare provider.

What special dietary instructions should I follow?

There are no specific dietary restrictions associated with chloramphenicol use. However, it is important to follow a balanced diet and stay hydrated during treatment.

What should I do if I forget a dose?

If a dose is missed, it should be taken as soon as remembered, unless it is almost time for the next dose. In that case, the missed dose should be skipped, and the regular dosing schedule resumed. It is important not to double the dose to make up for a missed one.

What side effects can this medication cause?

Common side effects of chloramphenicol include nausea, vomiting, diarrhea, headache, dizziness, and temporary changes in vision (when used topically). Serious side effects may include bone marrow suppression, aplastic anemia, and gray baby syndrome (in newborns).

What should I know about storage and disposal of this medication?

Chloramphenicol should be stored at room temperature, away from moisture and heat. It is important to follow any specific storage instructions provided with the medication. Unused or expired medication should be disposed of properly according to local regulations.

In case of emergency/overdose

In case of overdose or emergency, immediate medical attention should be sought. Symptoms of overdose may include severe vomiting, diarrhea, confusion, hallucinations, and convulsions.