ZINC CHLORIDE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ZINC CHLORIDE (ZINC CHLORIDE).
Zinc chloride exerts its effects primarily through inhibition of copper absorption and modulation of immune function. It competitively inhibits copper uptake at the intestinal mucosa, leading to copper deficiency, which is the basis for its use in Wilson's disease. Topically, it acts as an astringent and has antiseptic properties due to precipitation of proteins.
| Metabolism | Zinc chloride is not significantly metabolized; it is primarily eliminated via fecal excretion. Absorbed zinc is distributed widely and excreted mainly through the gastrointestinal tract. |
| Excretion | Zinc chloride is primarily excreted in the feces (approximately 90%) via biliary and pancreatic secretions, with renal excretion accounting for about 10% under normal homeostatic conditions. Unabsorbed zinc is eliminated in feces; absorbed zinc is mainly excreted through the gastrointestinal tract. |
| Half-life | The terminal elimination half-life of zinc chloride is approximately 12-24 hours for the initial phase, with a longer terminal half-life of 2-3 months for the slow-turnover pool in bone and muscle. Clinically, this requires cautious monitoring during chronic supplementation to avoid accumulation. |
| Protein binding | Approximately 60-70% of zinc in serum is bound to albumin, with 30-40% bound to α2-macroglobulin and other proteins (e.g., transferrin). Free zinc (ionized) comprises less than 1% of total serum zinc. |
| Volume of Distribution | The apparent volume of distribution for zinc chloride is 1.5-2.5 L/kg, reflecting extensive distribution into tissues, particularly muscle, bone, and organs (e.g., liver, kidney). A large Vd indicates that zinc is not confined to plasma and requires loading doses for rapid repletion. |
| Bioavailability | Oral: Bioavailability of zinc from zinc chloride is 20-30% on an empty stomach, but can be reduced to 10-15% when taken with food (especially phytate-rich meals). Intramuscular: Not routinely used but has near 100% bioavailability if administered properly, though painful and not recommended. Intravenous: 100% bioavailability. |
| Onset of Action | Intravenous: Onset of action for correcting zinc deficiency is within 24-48 hours, as measured by normalization of serum zinc levels and resolution of clinical symptoms (e.g., dermatitis, diarrhea). Oral: Onset is slower, typically 1-2 weeks for symptomatic improvement, as absorption is influenced by dietary factors and intestinal health. |
| Duration of Action | Intravenous: Duration of action depends on dosing interval; for maintenance therapy, effects last 24-48 hours post-infusion. Oral: With daily supplementation, sustained effects are achieved; duration of action for a single oral dose is approximately 6-12 hours due to homeostatic regulation and rapid clearance of excess zinc. |
| Molecular Weight | 136.28 |
Intravenous: 2.5-5 mg zinc (as chloride) per day, typically added to total parenteral nutrition (TPN) solutions.
| Dosage form | INJECTABLE |
| Renal impairment | No specific GFR-based dose adjustment guidelines; caution in severe renal impairment due to potential accumulation. |
| Liver impairment | No specific Child-Pugh-based modifications; generally administered as supplement in TPN; monitor zinc levels in severe hepatic impairment. |
| Pediatric use | Intravenous (TPN): Preterm infants: 400 mcg/kg/day; term infants up to 5 years: 100 mcg/kg/day; children 5 years and older: 2.5-5 mg/day. |
| Geriatric use | No specific dose adjustment required; use lower end of dosing range (2.5-5 mg/day) and monitor zinc levels. |
| 1st trimester | Zinc chloride is essential for fetal development; however, excessive doses (supratherapeutic) may cause toxicity. Recommended dietary allowance (RDA) should not be exceeded. Use only if clearly needed. |
| 2nd trimester | Continue to avoid excessive intake; maintain RDA levels. Potential for maternal toxicity with high doses. |
| 3rd trimester | Avoid high doses near term; possible risk of copper deficiency in neonate with prolonged high maternal zinc intake. |
Clinical note
Comprehensive clinical and safety monograph for ZINC CHLORIDE (ZINC CHLORIDE).
| Placental transfer | Zinc crosses the placenta via active transport; fetal levels are regulated. High maternal doses may saturate transport. |
| Breastfeeding | Zinc is excreted into breast milk in small amounts; levels correlate with maternal intake. Excessive maternal doses may lead to infant zinc toxicity or copper deficiency. Use only at RDA doses. |
■ FDA Black Box Warning
WARNING: Severe allergic reactions (including anaphylaxis) have been reported with injectable zinc chloride. Facilities for emergency resuscitation must be immediately available.
| Serious Effects |
Hypersensitivity to zinc chlorideSevere renal impairment (risk of accumulation)
| Precautions | Use with caution in patients with renal impairment due to risk of accumulation, Monitor serum copper levels during long-term therapy for Wilson's disease, May cause gastrointestinal irritation (oral use), Intravenous administration may cause phlebitis or extravasation injury, Avoid prolonged topical use on broken skin |
| Food/Dietary | High-fiber foods, phytates (e.g., whole grains, legumes), and calcium supplements can inhibit zinc absorption. Avoid taking zinc with dairy products or coffee. Zinc may also reduce copper absorption; ensure adequate copper intake. |
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| Lactation Rating | L2 (Probably Compatible) |
| Teratogenic Risk | Zinc chloride is essential for fetal development; deficiency increases risk of congenital malformations, including neural tube defects, growth restriction, and skeletal anomalies. High doses of zinc chloride (exceeding recommended dietary allowance) may cause maternal toxicity and potential fetal harm, but therapeutic doses (up to 40 mg elemental zinc daily) are generally considered safe. First trimester: adequate zinc crucial for organogenesis; supplementation indicated if deficient. Second and third trimesters: supports continued growth; excessive supplementation may cause copper deficiency and associated fetal risks. Overall, beneficial at recommended levels; toxic at high levels. |
| Fetal Monitoring | Monitor maternal serum zinc and copper levels periodically to prevent deficiency or toxicity. Assess fetal growth via ultrasound if prolonged therapy. For intravenous zinc chloride (parenteral nutrition), monitor maternal hemoglobin, electrolytes, and renal function. In cases of acute zinc chloride ingestion (e.g., toxicity), monitor maternal and fetal vital signs, gastrointestinal effects, and serum zinc levels. |
| Fertility Effects | Zinc is essential for normal reproductive function. Deficiency in males can cause hypogonadism, impaired spermatogenesis, and reduced fertility; in females, it can affect ovulation and implantation. Supplementation to correct deficiency improves fertility. High doses of zinc chloride (e.g., >100 mg/day) may impair sperm quality and cause adverse reproductive effects in animal studies. No evidence of direct negative impact on fertility at recommended doses. |
| Clinical Pearls | Zinc chloride is highly corrosive and can cause severe mucosal irritation; use only in well-diluted solutions. Parenteral zinc chloride is reserved for total parenteral nutrition and should be administered in a central line due to phlebitis risk. Monitor serum zinc levels to avoid toxicity, especially in renal impairment. |
| Patient Advice | Do not apply zinc chloride directly to broken skin or open wounds as it can cause burning or stinging. · Take oral zinc supplements with food to reduce gastrointestinal upset, but avoid high-fiber or phytate-rich foods that reduce absorption. · Report any signs of zinc overdose, such as metallic taste, nausea, vomiting, or diarrhea. |