Minocycline

What is minocycline?

Minocycline (brand names Minocin®, Solodyn®, Arestin®) is a tetracycline-based antibiotic. It is used to treat a variety of bacterial infections in cats and dogs. It is sometimes used in place of doxycycline (Vibramycin®). Minocycline is frequently used as part of the heartworm adulticide treatment protocol and for certain tick-borne infections, such as Lyme disease.

Its use in dogs and cats is off label (extra label). 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 is minocycline given?

• Minocycline is given by mouth. It is available as capsules, tablets, and flavored oral suspension.
• It can be given with or without food but works best if given on an empty stomach.
• If your pet seems sick or vomits after giving this medication, try giving the next dose with food.
• DO NOT give this medication as a dry pill. Give with a moist treat or a small amount of liquid. This is especially important in cats. If the pill becomes lodged in the throat or esophagus, it may cause ulcers.
• After giving this medication to your cat, follow the dose with a syringe of 3-5ml of water to prevent esophageal ulcers.

This medication will take effect in one to two hours but outward effects may take a few days to be recognized.

What if I miss giving my pet the medication?

If you miss a dose, 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?

Minocycline may cause the following side effects. If these side effects are severe or worsen, contact your veterinarian:

• Nausea, vomiting
• Reduced appetite
• Diarrhea
• Sunburn or reddening in hairless areas (e.g., nose, eyelids, ears)

Serious adverse reactions may occur. If any of the following signs develop, stop giving minocycline and contact your veterinarian immediately:

• Liver issues
• Ear problems
• Severe gastrointestinal effects
• Yellowing of the skin or eyes
• Weakness
• Lethargy
• Loss of hearing
• Superinfections of other types of bacteria or fungus (when used long-term)

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 short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

DO NOT USE minocycline in:

• Pets that have a hypersensitivity (allergy) to it or drugs like it (e.g., doxycycline, tetracycline)
• Pets that are breeding, pregnant, or nursing (except when absolutely necessary)

USE WITH CAUTION in:

• Pets with a history of liver problems
• Pets that are young and still developing bones and teeth
• Pets with certain types of kidney failure

Are there any drug interactions I should be aware of?

Several medications should be used with caution when given with minocycline, including:

• Bismuth (Pepto-Bismol®) or gastro protectants (e.g., sucralfate, brand name Carafate®)
• Oral antacids
• Oral iron
• Penicillin
• Zinc

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 let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
• At home, monitor for any side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.

How do I store minocycline?

• Store minocycline in a tightly sealed container at room temperature (20°C-25°C or 68°F-77°F) and protect from light.
• Keep the container out of reach of children and pets.

What should I do in case of an 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.