'Just in case' medications
If you are treating a dog or cat with chemotherapy, I recommend you send them home with ‘just in case’ medications with their first chemotherapy treatment.
Pets tolerate chemotherapy far better than humans, but if the pet starts to vomit or have diarrhoea late at night, owners can give these 'just in case' medications to their pet, rather than go into an emergency hospital or wait until the next day to get these medications.
It is important to try to do everything possible to prevent pets from getting sick during chemotherapy, particularly for owners where toxicity may result in discontinuing therapy.
What are the ‘just in case’ medications?
- Anti-nausea
- Appetite stimulants
- Anti-diarrhoeal
What do you recommend, and at what dosage?
In DOGS, I like the following:
1. Anti-nausea - to administer at the first signs of inappetence, nausea or vomiting.
o Metoclopramide (Maxolon®)
Dosage: 0.1-0.5 mg/kg orally up to three times a day.
Indication/s: This is a cheap and great first-line treatment for dogs with mild inappetence, nausea or vomiting. It is particularly great when administering vinca alkaloids such as vincristine, where gastrointestinal ileus may occur.
o Maropitant (Cerenia®)
Dosage: 2-8 mg/kg orally once daily.
Indication/s: This can be an expensive medication in a large breed dog. However, it is a great first-line or second-line treatment for dogs with mild to severe inappetence, nausea or vomiting. The main advantage is that it only needs to be administered once a day.
o Ondansetron (Zofran®)
Dosage: 0.5-1 mg/kg orally up to three times a day, or 4 mg for a small dog and 8 mg for a large dog.
Indication/s: This can also be an expensive medication. However, it is a great first-line or second-line treatment for dogs with mild to severe inappetence, nausea or vomiting. Ondansetron can come in a dissolvable wafer form, which is great for pets that are difficult to medicate orally. It does not need to be swallowed and takes about five seconds to dissolve in the oral mucous membranes (e.g. tongue and buccal mucosa).
2. Appetite stimulants – to administer in dogs that are underweight or not eating well.
o Capromorelin (Entyce®)
Dosage: 3 mg/kg orally once daily. Available in 10 mL, 15 mL and 20 mL bottles.
Indication/s: Inappetence, anorexia and cachexia. This is an oral solution. Therefore, it is great for owners that have difficulties administering oral tablets to their dog. This is a great appetite stimulant manufactured in the USA. Unfortunately, it not available in some countries such as Australia.
o Mirtazapine
Dosage: 0.5-1.5 mg/kg orally once daily. Do not exceed 30 mg/dog/day
Indication/s: Inappetence, anorexia and cachexia. This can sometimes work well when anti-nausea medications fail to help.
3. Anti-diarrhoeal – to administer at the first signs of diarrhoea.
o Probiotics (e.g. Protexin® paste).
Dosage: Depends on the source. Please follow the instructions on the bottle. Usually, once a day oral powder, tablet or capsule, that can be administered with food.
Indication/s: I usually recommend this for dogs with mild diarrhoea, in all dogs receiving chemotherapy or Palladia®, dogs with gastrointestinal disease, or dogs prone to diarrhoea. It can be administered for the whole duration the dog is undergoing chemotherapy or Palladia®, and it can work alongside some antibiotics.
o Smectite
Dosage: 0.5 g/kg orally daily - given as a divided dosage 2-3 times throughout the day (e.g. 0.25 g/kg twice daily or 0.17 g/kg three times daily).
Indication/s: Diarrhoea. Stop when the diarrhoea has resolved.
o Metronidazole
Dosage: 10 mg/kg orally twice daily for at least five days.
Indication/s: Diarrhoea, particularly due to Palladia®.
o Bismuth salicylate oral suspension (Peptosyl® or Pepto-Bismo®)
Dosage: Please follow the instructions on the bottle. Can be administered up to four times a day.
Indication/s: Acute intractable diarrhoea, particularly after doxorubicin chemotherapy. Stop when the diarrhoea has resolved.
o Loperamide (Imodium®)
Dosage: 0.1-0.2 mg/kg orally up to three times a day.
Indication/s: Rarely indicated except for acute intractable diarrhoea that is non-responsive to other anti-diarrhoeal medications. Stop when the diarrhoea has resolved.
In CATS, I like the following:
1. Anti-nausea
o Maropitant (Cerenia®)
Dosage: 2mg/kg orally once daily.
Indications: Similar to dogs. See previous.
o Ondansetron (Zofran®)
Dosage: 0.5-1 mg/kg orally up to three times a day, or 2mg for a small cat and 4mg for a large cat.
Indications: Similar to dogs. See previous.
2. Appetite stimulants
o Mirtazapine
Dosage: 2 mg/cat orally once daily. Sometimes recommended every second day (e.g. chronic renal failure).
Indication/s: Similar to dogs. See previous. In some countries (such as in the USA), mirtazapine comes in a transdermal ointment (Mirataz®) which is great for cats that are difficult to medicate orally.
3. Anti-diarrhoeals
o Probiotics (e.g. Protexin® paste)
Dosage: Depends on the source. Please follow the instructions on the bottle. Usually once a day oral powder, tablet or capsule.
Indication/s: Similar to dogs. See previous.
o Loperamide (Imodium®)
Dosage: 0.1-0.2 mg/kg orally up to three times a day.
Indication/s: Similar to dogs. See previous.
o Note: Unless the diarrhoea is very severe, I do not usually prescribe metronidazole in cats because it can make some cats inappetent and nauseous.
In summary, for pets with cancer that are otherwise clinically well, I usually dispense one anti-nausea or appetite stimulant, and one anti-diarrhoeal medication to give at the first signs of illness. However, for pets with cancer that are already clinically unwell or for owners where a sick pet may result in discontinuing therapy, I usually dispense one or a combination of medications prophylactically with chemotherapy. Yes, it can be quite a lot of medications and expensive, but I rather the pet feels well during therapy.
Vets, I hope this information is helpful. If you have a question about any of these ‘just in case’ medications, please do not hesitate to get in touch by clicking here.