Your horse has been diagnosed with PPID and you are about to start treating him/her with Prascend or pergolide. Here are some of the most frequently asked questions regarding Prascend/pergolide. Important sources of information: NOAH data sheet for Prascend VMD SPC for Prascend EEG Recommendations for the Diagnosis and Treatment of PPID |
A. No. The Equine Endocrinology Group, made up of the leading experts on PPID, now recommends introducing Prascend gradually "by giving partial doses for the first four days or by administering half the dose morning and evening". EEG Recommendations for the Diagnosis and Treatment of PPID Table 6.
The ECIR group has been recommending introducing the dose of pergolide slowly for years:
"Whether increasing or decreasing dosage or just starting pergolide for the first time taper at a rate of 0.25 mg every three days." ECIR - Treatment of PPID.
When prescribed for humans with Parkinson's Disease, pergolide is always introduced very gradually - see Pergolide Dosage and Administration - Pergolide - www.drugs.com.
Generally the initial amount given should be 0.25 mg, slowly built up in 0.25 mg increments to reach the prescribed dose. The urgency of reaching full dose and the horse's reaction to pergolide will dictate how quickly the prescribed dose is reached - this must be discussed with the prescribing vet. Splitting this between morning and evening would be next to impossible - good results are usually seen when the dose is given once a day and slowly built up.
Your vet should be able to obtain a pill cutter from Boehringer Ingelheim to help you split pills into 0.25 mg - see Splitting Prascend Tablets.
Q. What is the "Pergolide Veil"?
A. The "Pergolide Veil" is a phrase given to the side effects of inappetence and depression commonly seen when a horse starts on pergolide/Prascend.
Research carried out for the FDA New Animal Drug Application for Prascend in 2011 found that of horses with PPID given a starting dose of 1 mg Prascend, 33% had a decreased appetite at one or more meals, that was usually transient, and 10% of horses that had not previously shown signs of lethargy became lethargic - details here.
Q. Can the "Pergolide Veil" be avoided?
A. As above, when pergolide is introduced slowly (in 0.25 mg increments building up over several days), the "Pergolide Veil" seems to be experienced less (anecdotal).
It can be concerning when horses go off their feed when starting pergolide, particularly if they are already underweight. One owner reported success when her horse (who was ill with a suspected bacterial infection and had lost a significant amount of weight) was given Periactin (cyproheptadine) as an appetite stimulant for the first couple of weeks while starting on Prascend (the horse had previously been tried on Prascend and had gone off feed). No side effects of either Prascend or Periactin were seen.
Q. Does it matter what time of day I give Prascend/pergolide?
A. No. There is currently no recommendation for giving Prascend/pergolide at any particular time of day - this was confirmed by Dr Marian Little in The Horse.com's Ask the Vet Live Managing Horses with PPID in February 2014.
Q. Should pergolide/Prascend be given once or twice a day?
A. Once a day, usually. The NOAH data sheet for Prascend says "The product should be administered orally, once daily."
Q. What is the difference between pergolide and Prascend?
A. Pergolide is the name of the drug, i.e. the active ingredient (pergolide mesylate).
When this article was written in 2014, Prascend was the only form of pergolide that was licensed for use in horses. It is made by Boehringer Ingelheim and comes in 1 mg tablets, which can be easily broken in half. As at 2024 there are several brands of pergolide available - see Pergolide - brand names include: Prascend, Pergoquin, Pergolife, Prasequine, Pergocoat.