Ronidazole

What is ronidazole?

Ronidazole (brand names: Belga®, Ridsol-S®, Ronida®, Ronivet®, Ronizol®, Turbosol®, Tricho Plus®, Trichocure®, Trichorex®) is an antiprotozoal, antiparasitic medication used to treat Tritrichomonas foetus infections in cats. It has also been used to treat trichomonas species in pet birds and to treat giardia in pet dogs and cats.

Its use in pet cats, dogs, and birds to treat parasitic infections 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 ronidazole given?

• Ronidazole is given by mouth in the form of a capsule or liquid. Do not open or crush capsules.
• Measure liquid forms carefully.
• Ronidazole should be given with food to prevent stomach upset.
• Wear gloves when administering this medication.
• Wear gloves when handling feces, urine, vomit, saliva, or cat litter.

This medication should take effect within 1 to 2 days, and improvements in clinical signs should follow.

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.

If you are giving this medication once daily, and it is within 12 hours of the next dose, skip the missed dose and wait for the next scheduled time. Do not give the pet two doses at once.

Are there any potential side effects?

Ronidazole may cause the following side effects:

• Vomiting or decreased appetite

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

• Tremors
• Severe tiredness
• Lack of appetite
• Incoordination, dizziness
• Fever
• Seizures
• Weakness, collapse
• Abnormal behavior

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 ronidazole in pets that:

• Are allergic to it or other nitroimidazoles such as metronidazole

USE WITH EXTREME CAUTION in pets that:

• Are pregnant (benefits should outweigh risks)
• Lactating animals (use a milk replacer)

USE WITH CAUTION in pets that:

• Have seizures

Dogs given this medication long term (for 2 years) had signs of testicular toxicity.

This medication is potentially carcinogenic to humans as it has been shown to cause cancer in mice and increase the rate of certain cancers in rats. As a precaution, wear gloves when administering this medication.

Are there any drug interactions I should be aware of?

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

• Cimetidine
• Cyclosporine
• Ketoconazole
• Phenobarbital

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.
• Your veterinarian may check a polymerase chain reaction (PCR) test for the parasite, although this test is not always accurate.

How do I store ronidazole?

• Store this medication in the freezer, in a tight container.
• Protect from light, unless otherwise instructed on the label.

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.