Ascorbic Acid
**Ascorbic acid** (Vitamin C) is a water-soluble vitamin essential for collagen synthesis, tissue repair, and antioxidant defense. While most domestic animals (such as dogs, cats, and horses) synthesize adequate amounts of Vitamin C endogenously in their liver, certain species—most notably **guinea pigs, non-human primates, and some bats and birds**—lack the enzyme L-gulonolactone oxidase and require dietary supplementation. In veterinary medicine, ascorbic acid is primarily used to: * Treat and prevent scurvy in susceptible species (e.g., guinea pigs). * Serve as an adjunctive antioxidant therapy in critical care or hemolytic events. * Act as a urinary acidifier. * Assist in the management of specific toxicities, such as red maple leaf toxicosis in horses or acetaminophen toxicity, due to its methemoglobin-reducing properties.
Mecanismo: Ascorbic acid acts as a vital coenzyme and a powerful water-soluble antioxidant. * **Collagen Synthesis**: It is an essential cofactor for the enzymes **prolyl hydroxylase** and **lysyl hydroxylase** → facilitates the hydroxylation of proline and lysine residues → allows for the formation of a stable collagen triple helix. * **Antioxidant Activity**: Scavenges reactive oxygen species (ROS) → protects lipid membranes, DNA, and proteins from oxidative damage. * **Methemoglobin Reduction**: Assists in the reduction of methemoglobin back to functional hemoglobin, which is beneficial in certain oxidative toxicities. * **Iron Absorption**: Enhances the gastrointestinal absorption of non-heme iron and regulates iron transport.
Vías de administración
Contraindicaciones
- Patients with a history of urate or calcium oxalate urolithiasis
- Use with caution in patients with iron storage diseases (e.g., hemochromatosis)
- Patients with a history of calcium oxalate or urate urolithiasis (due to urine acidification)
Efectos adversos
- Gastrointestinal upset (diarrhea) with high oral doses
- Pain or tissue irritation at the injection site (IM or SC)
- Increased risk of calcium oxalate urolithiasis with chronic high-dose administration
- Gastrointestinal upset (diarrhea) at high oral doses
- Pain at injection site (IM/SC)
- Potential to acidify urine, which may increase the risk of oxalate or urate urolithiasis
Interacciones farmacológicas
- Deferoxamine · Concurrent use may exacerbate tissue iron toxicity, particularly in the heart. · major
- Urine acidifying agents · May have additive acidifying effects, potentially increasing the risk of crystalluria. · moderate
Monitoreo
- Clinical signs of disease resolution (e.g., improvement of scurvy symptoms in guinea pigs)
- Urine pH (if utilized specifically as a urinary acidifier)
- Resolution of clinical signs of scurvy (in susceptible species)
- Urine pH (if using high doses)
Sobredosis
Ascorbic acid is generally very safe due to its water-soluble nature; excess amounts are rapidly excreted in the urine. Massive acute overdoses may cause **gastrointestinal disturbances** (such as diarrhea) or **mild acidosis**. Chronic overdosage significantly increases the risk of **calcium oxalate urolithiasis**.
La referencia de fármacos de VetSheet está destinada a médicos veterinarios como apoyo a la decisión clínica; no sustituye el juicio profesional ni la información vigente del fabricante.