Re: Paralyzed dog with FCE
Posted: Sun May 19, 2019 5:31 am
Congratulations!
https://handicappedpet.net/helppets/
https://handicappedpet.net/helppets/viewtopic.php?f=4&t=20268
This is what my Pill Book Guide to Medication for Your Dog and Cat says exactly:The Leakers: Disorders of Micturition and Continence
Disorders of Bladder Emptying with Increased Urethral Tone
1. Phenoxybenzamine; this is an alpha-adrenergic blocking agent, which relaxes the internal urethral sphincter. A side effect is hypotension. The dose is 0.25 mg/kg PO TID (dog) and 0.5 mg/kg PO BID (cat). This drug takes 3 - 5 days to reach therapeutic levels. Other alpha-blocking agents with a similar effect on the internal sphincter but more side effects are acepromazine (hypotension, sedation) and prazocin (hypotension). Be cautious when using these drugs simultaneously.
2. Diazepam; this is a centrally acting skeletal muscle relaxant, which decreases external urethral sphincter tone and spasm. Side effects are sedation and incoordination. Hepatotoxicity occurs in cats with repeated oral administration. Other drugs with a similar mechanism are dantrolene and baclofen.
Decreased Detrusor Contractility (e.g. atonic bladder)
1. Bethanecol; this is a cholinergic agent which stimulates detrusor contractions. Side effects are abdominal cramping and gastrointestinal effects. This drug has a weak effect on nicotinic receptors in the internal urethral sphincter, and is therefore best when used in combination with an alpha-adrenergic blocker like phenoxybenzamine. The dose is 2.5 - 10 mg PO BID to TID (dog) and 2.5 mg PO BID (cat). Other agents suggested to increase detrusor tone include metoclopramide and prostaglandin E2.
It also says:Bethanechol should only be used when the urethra is open, as when a catheter is in place, or with urethral relaxants because bethanechol can cause contraction of urethral smooth muscle as well. Theoretically, the bladder could rupture if bethanechol is given when the urethra is blocked, or in spasm.
According to the MarVistaVet article above, urethral relaxants include diazepam or phenoxybenzamine, or some members here have been given robaxin for the same purpose.Food Interactions
There are usually fewer side effects if given on an empty stomach.
Usual Dose
Contact your veterinaria if salivation or GI upset are pronounced or persist. Your animal may need a reduced dose.
Dogs: 5-25 mg orally 3 times a day
Plumb's Veterinary Drug Handbook 4th ed (not the latest edition) re Bethanechol says:https://www.marvistavet.com/bethanechol-chloride.pml wrote:If the patient’s urinary tract is not obstructed but has excess tone, it is helpful to combine bethanechol with a medication to relax the lower sphincter and urethra: diazepam or phenoxybenzamine.
People have made a lot of favorable comments about phenoxybenzamine, but I was told it takes a few days to build up in the system and reach full effect.If urinary outflow resistance is increased due to enhanced urethral tone (not mechanical obstruction!), bethanechol should only be used in conjunction with another agent that will sufficiently reduce outflow resistance (eg., diazepam, dantolene (striated muscle) or phenoxybenzamine (smooth muscle)).