What is spironolactone + hydrochlorothiazide?
Spironolactone + hydrochlorothiazide is a combination medication used to remove excess fluid and salt from the body due to heart failure in cats and dogs.
This medication can be used in combination with other drugs to lower blood pressure and for protective effects on the heart muscle. Spironolactone + hydrochlorothiazide has also been used in dogs with fluid build-up in the abdomen due to liver failure.
It is used 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 spironolactone + hydrochlorothiazide?
- Spironolactone + hydrochlorothiazide comes in a tablet form. Tablets may be compounded into liquid.
- Tablets and compounded liquids are given orally (by mouth).
- Liquid medications must be measured carefully. Contact your veterinarian if you have trouble measuring or giving the medication.
- 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.
- Ensure access to fresh water at all times.
- 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 will take effect quickly, in about 1 to 2 hours, though outward signs may not be noticeable.
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 from spironolactone + hydrochlorothiazide?
Spironolactone + hydrochlorothiazide may cause the following side effects:
- excessive thirst and/or increased urination
- vomiting
- diarrhea
- water and/or electrolyte imbalances
- tiredness or decreased energy level
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
- fast heartbeat
- collapse
- pale gums
- excessive thirst with no urination
- severe, pruritic (itchy) sores on face – seen more often in cats, particularly Maine Coon cats
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.
This medication is short-acting, meaning that effects should stop after 24 hours but may be prolonged in pets with kidney and/or liver disease.
Are there any risk factors for this medication?
This medication should NOT BE USED in animals who:
- cannot produce urine or who have severe kidney disease
- have known allergies to any component of this medication or to related drugs (e.g. chlorothiazide)
- have elevated potassium levels
This medication should be USED WITH CAUTION in animals who:
- have reduced kidney function
- are pregnant or nursing
- have uncontrolled conditions where electrolytes or blood sugar can be out of balance (e.g., diabetes mellitus).
- have vomiting or diarrhea
- are allergic to sulfa drugs
Are there any drug interactions I should be aware of?
Certain medications should be USED WITH CAUTION when given with spironolactone + hydrochlorothiazide, including:
- other medications used to treat heart conditions and/or control blood pressure (e.g., aspirin, beta-blockers, calcium channel blockers, ARBs, digoxin, diuretics)
- cholestyramine
- immunosuppressants (e.g., methotrexate, cyclosporine)
- corticosteroids (e.g., dexamethasone, prednisone)
- calcium-containing medications and supplements
- mitotane
- NSAIDs (e.g., carprofen, meloxicam)
- supplements (e.g., potassium, iron, vitamin D)
- sulfa-/trimethoprim
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 there any monitoring that needs to be done with this medication?
- Baseline blood work (including electrolytes, BUN, creatinine) and baseline blood pressure should be checked before starting treatment, followed by rechecks as recommended by your veterinarian.
- Your veterinarian may schedule follow-up visits for monitoring and/or additional testing (ECG, chest X-rays, heart ultrasound, etc.) to ensure the medication is working. 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 spironolactone + hydrochlorothiazide?
- Store at room temperature in a tightly closed container, protected from light.
- Follow storage and expiration recommendations for specially compounded 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 to the medication, 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.
