Dolasetron

What is dolasetron?

Dolasetron is used in dogs and cats to treat nausea and vomiting. It is often used in pets receiving chemotherapy, in which nausea and vomiting are common side effects.

Dolasetron is used off-label in dogs and cats as there are no veterinary formulations available. 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 dolasetron?

• Dolasetron is given orally or by injection into the vein (IV) or injection under the skin (SQ).
• The injectable form is usually given at the veterinary hospital.
• The oral form of this medication is given by mouth, in the form of a tablet.
• This medication may also be compounded into other forms, in order to provide correct dosages for small dogs and cats.
• Dolasetron may be given with or without food.
• If vomiting occurs when dosed on an empty stomach, give future doses with food or a treat.
• Follow the instructions on the label of your product, in conjunction with your veterinarian’s directions.
• Give this medication at the same time daily.
• For chemotherapy-induced nausea, give this medication 30 minutes prior to receiving chemotherapy drugs.

This medication should take effect within 1 to 2 hours and improvement in clinical signs should follow.

What if I miss giving my pet the medication?

If you miss a dose of dolasetron, 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 from dolasetron?

In general, dolasetron is well tolerated in dogs and cats. Humans have reported headaches and dizziness when taking this drug.

Serious adverse reactions associated with this drug may occur without warning and could, in rare cases, lead to death. If any of the following signs develop, stop giving dolasetron and contact your veterinarian immediately:

• Sudden collapse
• Changes in heart rhythm (arrhythmia)

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 (e.g., irregular breathing, rash, fever, puffiness and swelling around the face) and notify your veterinarian if you have any concerns.

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 dolasetron in:

• Pets with a known hypersensitivity to this medication
• Pets with certain heart rhythm abnormalities (arrhythmia), such as atrioventricular (AV) blocks II or III
• Pets that have been diagnosed with a prolonged QT interval on ECG

USE WITH CAUTION in:

• Pets with gastrointestinal tract blockage
• Pets with electrolyte abnormalities, such as low potassium or low magnesium
• Pets taking other medications that may affect electrolyte levels
• Pets taking other medications that may cause abnormal heart rhythms (arrhythmia)
• Pets that have had multiple, high doses of certain types of chemotherapy

Are there any drug interactions I should be aware of?

Certain medications may interact with dolasetron and so it is important to tell your veterinarian about 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 dolasetron, including:

• Acepromazine
• Apomorphine
• Atenolol
• Buprenorphine
• Cimetidine
• Ciprofloxacin, moxifloxacin and other fluroquinolone antibiotics
• Cisapride
• Ketoconazole, itraconazole and other azole antifungals
• Metronidazole
• Miodarone
• Phonobarbital
• Quinidine
• Rifampin
• Serotonergic drugs (e.g., St. John’s wort, selegeline, methylene blue, selective serotonin reuptake inhibitors [SSRIs])
• Sotolal
• Tramadol

Is any monitoring needed with this medication?

• Baseline blood work is recommended to assess your pet's general health before starting this medication.
• Periodic blood work and heart rhythm monitoring may be advised. Your veterinarian may adjust the dose based upon these results and an assessment of how your cat or dog is responding clinically.
• An ECG is recommended in patients at risk for heart rhythm abnormalities.
• Your veterinarian will let you know when 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 side effects occur, discontinue use of the medication and contact your veterinarian.

How do I store dolasetron?

• Store tablets at room temperature (68°F to 77°F or 20°C to 25°C).
• Store compounded forms of this medication according to the label.
• Store in an airtight container.
• Protect from light and heat.
• 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 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.