Vitamin C Injectable

What is Vitamin C injectable?

Vitamin C injectable is a vitamin supplement used as an antioxidant to help treat certain toxicity syndromes or to create a more acidic urine in dogs and cats. It is also used in guinea pigs to treat scurvy. Various generic veterinary brands of Vitamin C injectable are available in North America.

In Australia, Vitamin C is approved for use in dogs, horses, and cattle as a nutritional supplement (VitaJect).

Vitamin C injectable is considered off label (extra label) in all veterinary species. Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

Most formulations of injectable Vitamin C have not been reviewed by the U.S. Food and Drug Administration (FDA)  for safety or effectiveness before they are sold to the public. Manufacturers of non-drug health products must ensure their products are safe and labeled accurately. The FDA requires that these non-pharmaceuticals contain a disclaimer that says, “This product is not intended to diagnose, treat, cure or prevent any disease.” Health Canada licenses “veterinary health products” after reviewing safety, efficacy, and manufacturing information provided by the manufacturer. These products are not tested by Health Canada. 

Your veterinarian is the best source of information about the safety of non-drug health products in pets. Just because a product is natural does not mean it is safe. All medicines and medicinal plants are potentially toxic if used inappropriately or given at high doses. Supplements can also have side effects, like pharmaceuticals. Few supplements and herbs have been subjected to rigorous scientific trials to determine their efficacy.  

Although the information in this handout may be helpful, it may also be incomplete and may not represent the full range of effects the supplement could have on your pet.

How is vitamin C injectable given?

• Vitamin C injectable comes as a solution for injection under the skin (SQ) or into the muscle (IM). 
• Injections may be given by veterinary personnel or at home by pet owners. 
• Follow your veterinarian’s directions for administration.

This medication can take several days to have full effects within the body, but side effects can occur immediately. Visible improvements are not always evident.

What if I miss giving my pet the medication?

If you miss a dose of vitamin C injectable, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.

Are there any potential side effects?

This supplement is usually well tolerated, and adverse reactions are uncommon at recommended doses. Vitamin C injectable may cause the following side effects:

• localized discomfort at injection site, when injected intramuscularly
• diarrhea (with high doses)
• increased risk for the formation of bladder stones, particularly in susceptible patients (with high doses)

Serious adverse reactions are possible with all injectable medications, including this supplement. They may occur without warning and could, in rare cases, lead to death. If any of the following signs develop, contact your veterinarian immediately:

• swelling
• hives
• changes in respiration
• vomiting
• prolonged signs of agitation

Drug sensitivities can develop over time, with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction each time this medication is used.  

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. Vitamin C injectable is a short-acting medication that will stop working within 24 hours, but effects may be prolonged in pets with liver or kidney disease.

Are there any risk factors for this medication?

Vitamin C injectable should NOT BE USED in:

• pets with liver disease
• pets with a known hypersensitivity or allergy to this supplement
• cats, if the formulation contains benzyl alcohol

Vitamin C injectable should be USED WITH CAUTION in pets who are: 

• prone to bladder stone formation
• diabetic
• pregnant, breeding or nursing, as safety in these animals has not been established

Are there any drug interactions I should be aware of?

Make sure your veterinarian is aware of any medications (including vitamins, supplements or herbal therapies) that your pet is taking before starting any new treatment. 

Several medications should be used with caution when given with vitamin C injectable, including:

• aeferoxaminealuminum hydroxide
• amantadine
• cobalamin
• cyclosporin (systemic)
• diethylstilbestrol
• doxorubicin
• ephedrine
• estradiol
• estriol
• ferrous sulfate
• mexiletine
• propranolol
• pseudoephedrine
• warfarin

Is any monitoring needed with this medication?

• At home, monitor for any side effects such as those noted above. If any side effects occur, discontinue the medication, and contact your veterinarian. 
• Follow your veterinarian’s recommendations regarding when your pet will need to be rechecked and what tests may need to be performed before and during treatment with this supplement.

How do I store vitamin C injectable?

• Store below 23°C (73°F). Do not freeze.
• Refrigerate to reduce the possibility of pressure build-up. Pressure build-up occurs after it is stored for a long time. Make sure to release pressure before use.
• Protect from light.
• Do not use it if you can see particles within the solution. 
• Keep out of reach of children and other animals.

What should I do in case of emergency?

• If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet's weight and symptoms. 
• Adverse effects should also be reported to the FDA or Health Canada.