chloramphenicol

Inhibits protein synthesis in susceptible bacteria at the level of the 50S ribosome.

Therapeutic effects:

Bacteriostatic action.

Spectrum:

Wide variety of gram-positive aerobic organisms including:
- Streptococcus pneumoniae and other streptococci,
- Some enterococci (especially vancomycin-resistant).
Gram-negative pathogens:
- Haemophilus influenzae,
- Neisseria meningitidis,
- Salmonella,
- Shigella.
Anaerobes:
- Bacteroides fragilis,
- Prevotella melaninogenica.
Other organisms inhibited:
- Rickettsia,
- Chlamydia,
- Mycoplasma.

Pharmacokinetics ⬆ ⬇

Absorption: IV administration results in complete bioavailabililty.

Distribution: Widely distributed to tissues. Crosses the blood-brain barrier with CSF levels 60% of serum values.

Metabolism/Excretion: Mostly metabolized by the liver; <10% excreted unchanged by the kidneys.

Half-Life: 1.5–3.5 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
IV	rapid	end of infusion	6–12 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity.

Use Cautiously in:

Severe renal impairment;
Severe hepatic impairment;
OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding;
Geri: risk of toxicity in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

Derm: rash, urticaria

EENT: blurred vision, optic neuritis

GI: bitter taste, diarrhea, enterocolitis, glossitis, nausea, stomatitis, vomiting

Hemat: bone marrow depression, APLASTIC ANEMIA, neutropenia, thrombocytopenia

Neuro: confusion, delirium, depression, headache, peripheral neuritis

Misc: ANGIOEDEMA, fever, GRAY SYNDROME(IN NEWBORNS)

Interactions ⬆ ⬇

Drug-drug:

May ↑ effects of oral hypoglycemic agents, warfarin, and phenytoin.
Phenobarbital or rifampin may ↓ levels and effectiveness.
May delay response to vitamin B or folic acid therapy.
Bone marrow depression may be additive with bone marrow–depressing agents (antineoplastics).

Route/Dosage ⬆ ⬇

IV (Adults ): 12.5 mg/kg every 6 hr (up to 100 mg/kg/day).
IV (Children ): Most infections: 12.5 mg/kg every 6 hr (maximum daily dose = 4 g). Bacteremia/meningitis: 18.75 to 25 mg every 6 hr.
IV (Infants > 2 wk): Most infections: 12.5 mg/kg every 6 hr (maximum daily dose = 4 g).Bacteremia/meningitis: 18.75 to 25 mg every 6 hr.
IV (Neonates >7 days and >2 kg): 25 mg/kg every 12 hr.
IV (Neonates birth–7 days or ≤2 kg): 25 mg/kg once daily.

Availability ⬆ ⬇

(Generic available)

Powder for injection: 1 g/vial

Assessment ⬆ ⬇

Assess for infection (vital signs, wound appearance, sputum, urine, stool, and WBC) at beginning of and throughout therapy.
- This drug should be administered systemically only to hospitalized patients or those under close medical supervision. Diagnosis should be confirmed with cultures prior to administration.
- Assess daily for signs of bone marrow depression (petechiae, sore throat, fatigue, unusual bleeding, bruising). Patients who have hepatic or renal impairment, infants, children, and older adults are at greatest risk of developing adverse effects.
Premature Infants and Neonates: Assess for gray syndrome (abdominal distention, blue-gray skin coloring, uneven breathing, unresponsiveness, low body temperature, cyanosis, hypotension, and respiratory distress).

Lab Test Considerations:

Monitor CBC every 2 days throughout therapy. The drug should be stopped if anemia, reticulocytopenia, leukopenia, or thrombocytopenia develops.

Toxicity and Overdose:

Monitor serum levels weekly, especially in low-birth-weight infants, patients with impaired or immature metabolic function, or patients receiving other medications metabolized by the liver. Therapeutic levels: peak, 15–25 mcg/mL; trough, 5–10 mcg/mL. Concentrations exceeding 25 mcg/mL ↑ risk of reversible bone marrow depression and gray syndrome.

Implementation ⬆ ⬇

IV Administration:

Reconstitute to a 10% solution by adding 10 mL of sterile water for injection or D5W to each 1 g. Do not use preparations containing benzyl alcohol in neonates.Concentration: Should not exceed 100 mg/mL. .
Rate: Inject slowly over at least 1 min.
Intermittent Infusion: Diluent: May be further diluted in 50–100 mL of D5W, D10W, D5/0.9% NaCl, D5/0.45% NaCl, D5/0.225% NaCl, D5/LR, 0.45% NaCl, 0.9% NaCl, or LR. Solution may form crystals at low temperatures. Shake well to dissolve crystals. Do not administer cloudy solutions.
Rate: Administer over 30–60 min.

Patient/Family Teaching ⬆ ⬇

Advise patient to contact health care professional immediately if signs of unusual bleeding; bruising; fever; sore throat; nausea; vomiting; diarrhea; or numbness, tingling, or burning pain or weakness in hands or feet occurs. Medication should be discontinued with the onset of these symptoms.
Reassure patient that bitter taste 15–20 sec following injection is limited to 2–3 min.
Instruct patient to report signs of superinfection (stomatitis, perianal itching, vaginal discharge, fever).
Emphasize the importance of follow-up exams. Bone marrow depression may develop wk to mo after drug therapy has been discontinued.
Rep: Advise patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇