Linezolid

What is linezolid?

Linezolid is an antibiotic used to treat multi-drug resistant, gram-positive bacterial infections in cats and dogs. Due to its use in multi-drug resistant infections in humans, linezolid’s use in veterinary medicine is limited to susceptible infections with documented resistance to other antimicrobials.

Its use is off label (extra label) in veterinary medicine. 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.

How do I give my pet linezolid?

• Linezolid comes in tablet and powder forms. Tablets and powders may be compounded into liquid form. An injectable form is available for use by your veterinarian in hospital.
• All forms to be given at home are given orally (by mouth).
• This medication may be given with or without food. 
• If your animal vomits or acts sick after receiving the drug on an empty stomach, try giving the next dose with food or a small treat. If vomiting continues, contact your veterinarian.  
• Liquid medications must be measured carefully and not shaken. Contact your veterinarian if you have trouble measuring or giving the medication.
• Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears that your pet is feeling better.

This medication should take effect within 1 to 2 hours, though effects may not be noticed outwardly right away. 

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember, and then wait the recommended time as prescribed by your veterinarian for the next dose. Do not give the pet two doses at once.

Are there any potential side effects from linezolid?

Linezolid may cause the following side effects:

• Decreased appetite
• Diarrhea
• Vomiting

The following reactions are rare, but if they occur, contact your veterinarian immediately:

• An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face
• Worsening infections
• Tremors, incoordination

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 over the entire course of treatment.

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This medication is moderate-acting, meaning that effects will last a few days, though effects may last longer in pets with kidney or liver disease.

Are there any risk factors for this medication?

DO NOT USE linezolid in animals who:

• Are allergic to any component of the medication or allergic to similar drugs
• Have received monoamine oxidase inhibitors (MAOIs) in the previous 14 days

USE WITH CAUTION in pets who:

• Have kidney and/or thyroid disease
• Have high blood pressure
• Have a history of seizures or diabetes mellitus
• Are sick, old, frail
• Are pregnant, nursing, or used for breeding

Are there any drug interactions I should be aware of?

Certain medications should be USED WITH CAUTION when given with linezolid, including: 

• Carbamazepine
• Chloramphenicol, rifampin
• Glycemic control agents (e.g., insulin, glipizide)
• MAOIs (e.g., amitraz, selegiline)
• Medications affecting serotonin (e.g., fluoxetine, mirtazapine, metoclopramide)
• Opioids and similar drugs (e.g., buprenorphine, hydrocodone, tramadol) 
• Reserpine
• Sympathomimetics (e.g., albuterol, phenylpropanolamine)
• Tricyclic antidepressants (e.g., amitriptyline, clomipramine)

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this medication?

• Your veterinarian will check a bacterial culture and sensitivity test before starting this medication and periodically throughout treatment.
• Baseline blood work may be collected before starting treatment and monitored throughout the course of treatment.
• Your veterinarian will schedule follow-up visits for monitoring. In this case, follow your veterinarian’s directions.
• At home, monitor for any abnormal changes. If any occur, discontinue the medication and contact your veterinarian.

How do I store linezolid?

• Store at room temperature of 77°F (25°C).
• Store in a tight container, protected from light and moisture.
• Follow storage and expiration recommendations for compounded and reconstituted formulas.
• Keep medication out of reach of children and pets.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Adverse effects should be reported to the FDA or Health Canada.