Proteinuria is defined as the presence of protein in the urine. Persistent and increased protein levels in the urine are abnormal. Proteinuria is often related to reduced survival in azotemic and non-azotemic dogs and cats.
Several medications are known to increase the incidence of proteinuria in cats and dogs. Learning which drugs cause proteinuria will help you better treat your patients with impending or current renal problems.
Phenylpropanolamine is a drug very commonly used for the control of urinary incontinence. Studies report a 13-15% incidence of proteinuria in cats and dogs who are taking phenylpropanolamine.
The typical dose for phenylpropanolamine is 2 mg/kg PO twice daily for dogs, and 1-2.2 mg/kg PO 2-3 times a day for cats. It is important to use the lowest effective dose and provide ample fresh water for your patients during therapy. This reduces the likelihood of developing proteinuria.
2) Tyrosine Kinase Inhibitors (Masitinib)
Tyrosine kinase inhibitors are antineoplastic agents used for some forms of mast cell tumors. Research shows and incidence of proteinuria in up to 10% of patients. This can be contraindicated if urine protein to creatinine ratio (UPC) is greater than one.
If your patient’s UPC level is greater than one, you may be required to adjustthe dosage. If the current dose is 12.5 mg/kg, discontinue the patient’s treatment until resolution and then, resume at 9 mg/kg. If the current dose is 9 mg/kg, permanently discontinue treatment, as you cannot give a smaller dose effectively.
Sulfonamides are antimicrobial agents used for respiratory, genitourinary, enteric, and soft tissue infections. Sulfonamides can precipitate in your patient’s urine, leading to acute renal failure by causing crystalluria, hematuria, and renal tubule blockage.
The risk of developing proteinuria increases with prolonged use and volume depletion. To reduce the risk to your patient, maintain adequate hydration and utilize the lowest effective dose for the shortest amount of time possible.
The use of steroids can cause mild increases of protein in your patient’s urine. To limit the risks of developing proteinuria, find the lowest steroid dose possible and use it for the shortest possible period of time.
Depending on the animal’s age, condition, dosage, and reason for use, consider monitoring their total plasma proteins and albumin. Once the steroid is stopped, the proteinuria should resolve itself.
Consider supplementing your patients with Omega-3 fatty acids. The anti-inflammatory properties found in Omega-3 fatty acids can be useful for animals experiencing renal failure.
Many medications can induce proteinuria in dogs and cats. Some drugs should be avoided altogether when possible, and some just require extra monitoring. When your patients are on proteinuria-inducing medications, monitor them regularly to avoid complications. When possible, find an alternative treatment to lower their risks of proteinuria.
Make sure that both you and your pharmacy team are aware of the most common medication causes of proteinuria and aim to use the lowest effective doses for the shortest period of time possible.
For more help with monitoring or finding alternative treatments to proteinuria-inducing medications, contact EPC at 888-733-0300 FREE ext 3 to speak with one of our experienced and friendly compounding pharmacists.
With best regards,
Drew Olson, DVM
National Director – Veterinary Division