CLINDAMYCIN PHOSPHATE IN 5% DEXTROSE IN PLASTIC CONTAINER
Clinical safety rating: safe
May enhance the effects of neuromuscular blocking agents Causes severe and sometimes fatal Clostridium difficile-associated diarrhea.
Clindamycin phosphate is a prodrug that is hydrolyzed to clindamycin, a lincosamide antibiotic. It reversibly binds to the 50S subunit of the bacterial ribosome, inhibiting protein synthesis by blocking peptide bond formation. It exhibits bacteriostatic activity against susceptible organisms.
| Metabolism | Clindamycin is primarily metabolized in the liver via oxidation to N-demethylclindamycin and sulfoxide metabolites. Some metabolism occurs via CYP3A4, but the overall contribution is minor. Approximately 10% of the drug is excreted unchanged in urine; the rest is excreted in bile and feces as metabolites. |
| Excretion | Approximately 10% of the administered dose is excreted unchanged in urine via glomerular filtration; about 90% is metabolized hepatically to inactive metabolites, which are excreted in bile and feces. Biliary excretion accounts for approximately 80% of total elimination, with enterohepatic recirculation. |
| Half-life | Terminal elimination half-life is 2-4 hours in adults with normal hepatic and renal function. In patients with severe hepatic impairment, half-life may increase to 8-12 hours. Renal impairment generally does not significantly alter half-life. In neonates, half-life ranges from 8-20 hours depending on gestational age. |
| Protein binding | Approximately 60-95% bound to plasma proteins, primarily to albumin. Binding is saturable and concentration-dependent, with higher free fraction at higher concentrations. |
| Volume of Distribution | Volume of distribution is approximately 0.6-1.2 L/kg. This exceeds total body water, indicating extensive tissue penetration. Clindamycin distributes well into bone, abscesses, and respiratory tissues; poor penetration into cerebrospinal fluid even with inflamed meninges. |
| Bioavailability | Intravenous: 100% bioavailable. Intramuscular: approximately 80-90% bioavailable. Oral: approximately 90% bioavailable (but not applicable for this IV formulation). Topical: systemic bioavailability less than 5%. |
| Onset of Action | Intravenous administration: Onset of antibacterial effect is rapid, with peak serum concentrations achieved immediately after infusion. Clinical response (reduction in fever, improvement in infection signs) typically within 24-48 hours. Intramuscular: Peak serum levels in 1-3 hours; clinical onset within 24-48 hours. Topical: Improvement in acne vulgaris lesions seen within 4-8 weeks. |
| Duration of Action | Serum concentrations decline over 6-8 hours; dosing interval is typically 6-8 hours due to rapid elimination. Clinical effect persists while serum levels exceed MIC; due to time-dependent killing, sustained levels are needed. Topical: once-daily application maintains effect; significant improvement seen by 4 weeks. |
| Molecular Weight | 461.44 |
1200-2700 mg/day IV divided every 6-12 hours; typical adult dose: 600-900 mg IV every 8 hours.
| Dosage form | INJECTABLE |
| Renal impairment | No dosage adjustment required for renal impairment; not significantly removed by hemodialysis. |
| Liver impairment | Severe hepatic impairment (Child-Pugh C): reduce dose by 50% or increase dosing interval; moderate impairment (Child-Pugh B): use with caution monitor liver function. |
| Pediatric use | Neonates: 15-20 mg/kg/day IV divided every 6-8 hours. Infants and children: 20-40 mg/kg/day IV divided every 6-8 hours. |
| Geriatric use | No specific dose adjustment; use with caution due to potential for decreased organ function and increased risk of Clostridioides difficile infection. |
| 1st trimester | Clindamycin is considered safe for use during the first trimester. Studies do not show an increased risk of major malformations. |
| 2nd trimester | Clindamycin is considered safe for use during the second trimester. No evidence of fetal harm from clinical studies. |
| 3rd trimester | Clindamycin is considered safe for use during the third trimester, including for group B Streptococcus prophylaxis. Avoid use near term if alternatives exist due to potential neonatal effects, but no significant adverse outcomes reported. |
Clinical note
May enhance the effects of neuromuscular blocking agents Causes severe and sometimes fatal Clostridium difficile-associated diarrhea.
| FDA category | Human |
| Placental transfer | Clindamycin crosses the placenta, achieving fetal serum concentrations approximately 50% of maternal levels. The degree of transfer is moderate, with evidence from pharmacokinetic studies showing measurable concentrations in fetal tissues and cord blood. |
■ FDA Black Box Warning
Clindamycin can cause severe and sometimes fatal colitis, including pseudomembranous colitis, due to Clostridium difficile overgrowth. This can occur during treatment or up to several weeks after discontinuation. If colitis is suspected, discontinue the drug and initiate appropriate therapy.
| Common Effects | Diarrhea (including C. difficile) |
| Serious Effects |
Hypersensitivity to clindamycin, lincomycin, or any component of the formulationHistory of antibiotic-associated colitis (including pseudomembranous colitis)
| Precautions | Clostridium difficile-associated diarrhea (CDAD): Can range from mild to fatal colitis; discontinue if significant diarrhea occurs., Hypersensitivity reactions: Severe reactions including anaphylaxis, Stevens-Johnson syndrome, and drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported., Neuromuscular blocking agents: Clindamycin may enhance the action of neuromuscular blocking agents, use with caution., Hepatic impairment: Use with caution in patients with hepatic impairment; monitor liver function., Renal impairment: No dosage adjustment required for mild-moderate impairment, but caution in severe impairment., Prolonged use: May result in overgrowth of nonsusceptible organisms, especially yeasts. |
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| Breastfeeding | Clindamycin is excreted into breast milk in low concentrations. The relative infant dose is estimated at <1% of the maternal weight-adjusted dose, which is considered low. However, there have been rare reports of adverse effects such as bloody stools or diarrhea in breastfed infants. Caution is advised, particularly in neonates or infants with gastrointestinal disease. Monitor the infant for signs of gastrointestinal disturbance. |
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Clindamycin crosses the placenta. Data from human studies are limited; however, based on animal studies and widespread clinical use, no specific teratogenic pattern has emerged. In first trimester, risk is considered low but cannot be ruled out; use only if clearly needed. In second and third trimesters, no evidence of fetal harm, but caution advised. The drug is classified as FDA Pregnancy Category B (prior to 2015 label change; current FDA labeling no longer uses categories). |
| Fetal Monitoring | Monitor maternal liver function and renal function if prolonged therapy. In neonates exposed in utero, monitor for possible alterations in gut flora and subsequent diarrhea. No specific fetal monitoring required, but consider fetal growth surveillance if used long-term. |
| Fertility Effects | No adverse effects on fertility have been reported in animal studies or human data. Clindamycin does not appear to impair fertility in either males or females. |
| Food/Dietary | No significant food interactions reported. However, patients should avoid alcohol during treatment as it may exacerbate gastrointestinal side effects and increase the risk of hepatotoxicity. |
| Clinical Pearls | Clindamycin phosphate in 5% dextrose is an intravenous formulation; ensure patient is not on warfarin as clindamycin potentiates anticoagulation. Monitor for pseudomembranous colitis due to C. difficile; discontinue if diarrhea occurs. Infusion rate should not exceed 30 mg/min to avoid hypotension or cardiac arrest. In renal impairment (CrCl <30 mL/min), dosing interval should be extended to every 12 hours. Avoid in patients with myasthenia gravis or neuromuscular disorders due to potential neuromuscular blockade. |
| Patient Advice | This medication is given through a vein to treat bacterial infections. · Do not stop taking this medication abruptly unless directed by your healthcare provider. · If you experience severe or persistent diarrhea, especially with blood or mucus, contact your doctor immediately as this may be a sign of a serious intestinal condition. · Inform your healthcare provider if you have a history of kidney disease, liver disease, or gastrointestinal disorders. · This medication may cause a metallic taste in the mouth, which is usually temporary. · Report any signs of allergic reaction, such as rash, itching, swelling, or difficulty breathing. · Avoid alcohol consumption during treatment as it may increase the risk of side effects. |