Acute vomiting in cats: maropitant vs metoclopramide, ondansetron or no treatment — LIKELY

In cats with acute vomiting, does maropitant (vs metoclopramide, ondansetron, or placebo/no treatment) stop vomiting more reliably?

Shelf #375 · gate-verified and displayed under the developer's blinded-trial rule

LIKELY: Maropitant stops vomiting in cats — that much is well supported against placebo or no treatment. In blinded or randomised challenge trials it cut emesis from 40% to 4% when given orally 18 hours before morphine and dexmedetomidine, and from 20 of 34 cats vomiting on saline to 1 of 32 on subcutaneous maropitant; in the one blinded, placebo-controlled clinical trial, cats with chronic kidney disease given daily oral maropitant for two weeks vomited significantly less than placebo cats (P <0.01). Against the older antiemetics, superiority is NOT established in cats: the single randomised head-to-head (dexmedetomidine-induced vomiting, 64 cats) found maropitant, ondansetron and metoclopramide each significantly better than saline, with no significant difference among the three drugs. Two limits keep this at LIKELY: most of the evidence is emetogen-challenge work in healthy cats rather than spontaneous acute vomiting — direct clinical evidence is one chronic-vomiting CKD trial and one uncontrolled 8-cat transdermal case series — and across trials maropitant reduced vomiting and retching without reliably reducing the nausea signs of lip-licking and sialorrhoea. The dog comparison (Shelf #168) is a different shelf: maropitant's clear margin over metoclopramide in dogs has not been shown in cats. Drafted Nov 10, 2026 (VetMed build, topic #375); all figures from abstracts fetched and verified at drafting.

Martin-Flores 2016: oral maropitant 18 hours ahead cut emesis from 40% to 4% in cats given morphine and dexmedetomidine

Prospective, blinded, randomised controlled trial (record's own description)

Who: Cats: 98 healthy female domestic shorthair cats (96 analysed). Maropitant 8 mg orally in total (average 2.5 mg/kg) given 18 hours before intramuscular dexmedetomidine 20 µg/kg and morphine 0.1 mg/kg, vs no antiemetic treatment; signs recorded for 30 minutes after the sedatives.

Result: Emesis occurred in 4% of maropitant cats vs 40% of control cats — an absolute difference of 36 percentage points (the authors describe a 10-fold reduction). Retching was 8% vs 40% and lip-licking 30% vs 52% (all P <0.05). Sialorrhea did not differ (21% vs 22%). The authors conclude maropitant 8 mg orally was effective in reducing morphine- and dexmedetomidine-induced emesis when given as early as 18 hours in advance.

Watch out: An emetogen-challenge study in healthy cats, not spontaneous clinical vomiting; the control was no treatment rather than a matched placebo, and the record's blinding statement is taken as written. Effect is on vomiting and retching — nausea signs were only partly reduced.

Martin-Flores M, Sakai DM, Mastrocco A, Learn MM, Campoy L, Kirch PJ, Boesch JM, Gleed RD. Evaluation of oral maropitant as an antiemetic in cats receiving morphine and dexmedetomidine. J Feline Med Surg. 2016;18(11):921-924. PMID: 26534944. Registry ID: none in the record. MeSH: Administration, Oral · Analgesics, Non-Narcotic/administration & dosage,adverse effects · Analgesics, Opioid/administration & dosage,adverse effects · Animals · Antiemetics/*therapeutic use · Cats/physiology,*surgery · Dexmedetomidine/administration & dosage,adverse effects · Female · Hysterectomy/veterinary · Morphine/administration & dosage,adverse effects · Ovariectomy/veterinary · Prospective Studies · Quinuclidines/administration & dosage,*therapeutic use · Treatment Outcome · Vomiting/chemically induced,prevention & control,veterinary

Martin-Flores 2016 (JAVMA): subcutaneous maropitant vs saline — 1 of 32 cats vomited, vs 20 of 34 on saline

Randomised controlled trial (publication type in the record; MeSH carries Single-Blind Method)

Who: Cats: 66 healthy female domestic shorthair cats. Maropitant 1 mg/kg subcutaneously (n = 32) or saline 0.1 mL/kg subcutaneously (n = 34), given 20 hours before intramuscular dexmedetomidine 20 µg/kg and morphine 0.1 mg/kg.

Result: Only 1 of 32 maropitant cats vomited, whereas 20 of 34 control cats vomited (about 3% vs 59%, an absolute difference of about 56 percentage points). The incidences of emesis and retching were significantly lower with maropitant; the incidence of signs of nausea did not differ between groups. Injection discomfort scores (visual analogue scale, scored by observers unaware of treatment) were significantly higher for maropitant — the injection appeared to cause substantial discomfort.

Watch out: Healthy-cat challenge model again; the record establishes single-blinding (its MeSH carries Single-Blind Method) and unaware observers for the injection-response score, but does not separately state that emesis assessors were blinded. Maropitant given subcutaneously hurt — a real handling cost in a vomiting cat.

Martin-Flores M, Sakai DM, Learn MM, Mastrocco A, Campoy L, Boesch JM, Gleed RD. Effects of maropitant in cats receiving dexmedetomidine and morphine. J Am Vet Med Assoc. 2016;248(11):1257-61. PMID: 27172341. Registry ID: none in the record. MeSH: Analgesics, Non-Narcotic/administration & dosage,adverse effects · Analgesics, Opioid/administration & dosage,adverse effects · Animals · Antiemetics/administration & dosage,*therapeutic use · Cat Diseases/*chemically induced · Cats · Dexmedetomidine/administration & dosage,adverse effects · Drug Interactions · Female · Injections, Intramuscular/veterinary · Injections, Subcutaneous/veterinary · Morphine/administration & dosage,adverse effects · Nausea/chemically induced,prevention & control,veterinary · Quinuclidines/administration & dosage,*therapeutic use · Single-Blind Method · Visual Analog Scale · Vomiting/chemically induced,prevention & control,*veterinary

Quimby 2015: daily oral maropitant significantly reduced vomiting in cats with chronic kidney disease — the one clinical-patient trial

Randomised, placebo-controlled, blinded clinical trial (record's own description)

Who: Cats: 41 client-owned cats with stable IRIS Stage II or III chronic kidney disease and chronic vomiting and inappetence attributed to CKD, no known concurrent illness. Maropitant 4 mg orally daily (median 1.1 mg/kg, range 0.6–2.9) for 2 weeks vs placebo; 33 cats completed (21 maropitant, 12 placebo). Owners kept daily logs of vomiting, appetite and activity.

Result: There was a statistically significant decrease in vomiting in the cats that received maropitant (P <0.01). Appetite scores, activity scores, weight and serum creatinine did not differ significantly from placebo. The authors conclude maropitant palliated vomiting associated with CKD.

Watch out: This is chronic CKD vomiting, not acute undifferentiated vomiting, and the abstract reports no absolute vomiting rates — the size of the benefit cannot be quantified from the record, only its direction and significance. Eight of 41 enrolled cats did not complete the trial.

Quimby JM, Brock WT, Moses K, Bolotin D, Patricelli K. Chronic use of maropitant for the management of vomiting and inappetence in cats with chronic kidney disease: a blinded, placebo-controlled clinical trial. J Feline Med Surg. 2015;17(8):692-7. PMID: 25336450. Registry ID: none in the record. MeSH: Animals · Cat Diseases/*drug therapy · Cats · Double-Blind Method · Kidney Function Tests · Palliative Care/methods · Quinuclidines/*administration & dosage · Renal Insufficiency, Chronic/drug therapy,*veterinary · Vomiting/drug therapy,*veterinary

Gölgeli Bedir 2025: maropitant, ondansetron and metoclopramide all beat saline — and did not differ from each other (the treatment comparison made no difference)

Randomised four-arm comparative trial (random allocation in the record's MeSH; the abstract does not state blinding)

Who: Cats: 64 cats randomly allocated to saline 0.1 mL/kg subcutaneously, maropitant 1 mg/kg subcutaneously, ondansetron 0.22 mg/kg intramuscularly, or metoclopramide 1 mg/kg intramuscularly, 30 minutes before intramuscular dexmedetomidine 25 µg/kg. Vomiting duration and severity and nausea signs recorded for 30 minutes.

Result: The duration and severity of vomiting were significantly reduced in the maropitant, ondansetron and metoclopramide groups compared with saline, and retching and vomiting differed between saline and the drug groups (P <0.001). No significant difference was found among the maropitant, ondansetron and metoclopramide groups. Sialorrhoea and lip licking did not differ (P = 0.34 and P = 0.12).

Watch out: The only head-to-head in cats — a single-dose dexmedetomidine sedation model, not clinical acute vomiting, and the abstract does not state that assessors were blinded. Per-arm group sizes are not given in the abstract (64 cats in total), so the power to detect a difference between the drugs is unclear: 'no difference found' is not proof the three are equal.

Gölgeli Bedir A, Yanmaz LE, Okur S, Şenocak MG, Turgut F, Kocaman Y, Orhun ÖT, Ersöz U, Baykal B. The Effect of Maropitant, Ondansetron and Metoclopramide on Dexmedetomidine-Induced Vomiting in Cats. Vet Med Sci. 2025;11(1):e70152. PMID: 39792081. Registry ID: none in the record. MeSH: Animals · Cats · Dexmedetomidine*/administration & dosage,pharmacology · Ondansetron*/therapeutic use,pharmacology,administration & dosage · Antiemetics*/therapeutic use,administration & dosage · Metoclopramide*/therapeutic use,administration & dosage · Vomiting*/veterinary,chemically induced,drug therapy,prevention & control · Male · Female · Cat Diseases*/drug therapy · Quinuclidines*/administration & dosage,therapeutic use,pharmacology · Random Allocation

Martin-Flores 2017: oral maropitant 2–2.5 hours ahead also reduced emesis — 13% vs 32% — but did not eliminate it

Randomised controlled trial (publication type in the record; blinding not stated)

Who: Cats: 83 healthy female cats randomised to maropitant 8 mg orally in total (n = 39; mean dose 2.9 ± 0.6 mg/kg) or no treatment (n = 44), given 2–2.5 hours before intramuscular morphine 0.1 mg/kg and dexmedetomidine 20 µg/kg.

Result: Emesis occurred in 13% of maropitant cats vs 32% of controls (P = 0.03), an absolute difference of 19 percentage points; retching was 13% vs 36% (P = 0.012). Sialorrhea and lip licking did not differ between groups. The authors conclude maropitant significantly reduced, but did not eliminate, retching and vomiting at this shorter interval.

Watch out: No-treatment control and no blinding statement in the record. The margin here is smaller than in the 18-hour study (4% vs 40%) — but that is a comparison across two different studies, not a randomised test of timing, so it is a hint about the dosing interval, not a measured timing effect.

Martin-Flores M, Mastrocco A, Lorenzutti AM, Campoy L, Kirch P, Stone M, Learn MM, Boesch JM. Maropitant administered orally 2-2.5 h prior to morphine and dexmedetomidine reduces the incidence of emesis in cats. J Feline Med Surg. 2017;19(8):876-879. PMID: 27538868. Registry ID: none in the record. MeSH: Administration, Oral · Analgesics, Opioid/administration & dosage · Animals · Antiemetics/*administration & dosage · Cat Diseases/*prevention & control · Cats/physiology,*surgery · Dexmedetomidine/administration & dosage · Female · Injections, Intramuscular/veterinary · Morphine/administration & dosage · Ovariectomy* · Postoperative Nausea and Vomiting/prevention & control,*veterinary · Quinuclidines/*administration & dosage · Treatment Outcome

Hickman 2008: maropitant 1 mg/kg prevented xylazine-induced emesis and was highly effective against motion sickness in cats

Experimental safety, pharmacokinetic and efficacy programme (journal article; randomisation and blinding not stated in the record)

Who: Cats: cats in the maropitant (Cerenia) development programme — safety testing at 0.5–5 mg/kg subcutaneously for 15 days, single-dose oral/intravenous/subcutaneous pharmacokinetics, and efficacy testing against emesis induced by xylazine or by motion.

Result: A dosage of 1 mg/kg maropitant administered intravenously, subcutaneously or orally prevented emesis elicited by xylazine; the compound showed good oral antiemetic activity and a long (24-hour) duration of action, and 1.0 mg/kg was highly effective in preventing motion-induced emesis. Maropitant was well tolerated at doses at least 10 times the efficacious anti-emetic range, with no adverse clinical signs or pathological safety findings; terminal half-life was 13–17 hours.

Watch out: The abstract reports no group sizes or event counts, so these results cannot be weighed like the counted trials above; the emetogens (xylazine, motion) are experimental models, not clinical vomiting. Carded as the programme and safety foundation, not as a counted efficacy trial.

Hickman MA, Cox SR, Mahabir S, Miskell C, Lin J, Bunger A, McCall RB. Safety, pharmacokinetics and use of the novel NK-1 receptor antagonist maropitant (Cerenia) for the prevention of emesis and motion sickness in cats. J Vet Pharmacol Ther. 2008;31(3):220-9. PMID: 18471143. Registry ID: none in the record. MeSH: Animals · Cats · Female · Male · Metabolic Clearance Rate · Motion Sickness/etiology,prevention & control,*veterinary · Neurokinin-1 Receptor Antagonists* · Quinuclidines/adverse effects,pharmacokinetics,*therapeutic use · Vomiting/chemically induced,prevention & control,*veterinary

Boukaache 2022: transdermal maropitant in 8 cats with acute clinical vomiting — vomiting fell in 6 of 8, with no control group

Uncontrolled case series (publication type: Case Reports)

Who: Cats: 8 cats, more than 6 months old, weighing 2–7 kg, each with at least 2 episodes of vomiting in the previous 72 hours. Compounded transdermal maropitant (ground Cerenia tablets in a liposomal base) 4 mg per cat, applied to the inner pinna once daily for 5 days.

Result: A significant decrease in vomiting frequency was observed in 6 of the 8 enrolled cats; a reduction in nausea, with improved appetite, was observed in some cases. The authors conclude transdermal maropitant seems efficient in cats experiencing vomiting and call for dosing and pharmacokinetic studies.

Watch out: No comparator of any kind — vomiting that resolves on its own looks identical to vomiting stopped by the gel, and 2 of 8 cats did not improve. A compounded product with no pharmacokinetic verification in the record. This card shows the route is used in real acute cases; it cannot carry an efficacy claim.

Boukaache Y, Ferret ML, Khoukh VDK, Enache A, Iwaszkiw D, Bertin S, Bruno F. Evaluation of the efficacy of transdermal administration of maropitant in managing vomiting in cats. Open Vet J. 2022;12(5):618-621. PMID: 36589400. Registry ID: none in the record. MeSH: Cats · Animals · Administration, Cutaneous · Vomiting*/drug therapy,veterinary · Antiemetics*/therapeutic use · Nausea/drug therapy,veterinary · Quinuclidines

Synthesis: maropitant clearly beats no treatment in cats; against metoclopramide or ondansetron the one head-to-head found no difference

Synthesis

Who: Cats: healthy cats in emetogen-challenge trials (morphine/dexmedetomidine, dexmedetomidine alone, xylazine, motion), client-owned CKD cats with chronic vomiting, and 8 cats with acute clinical vomiting.

Result: Versus placebo or no treatment, maropitant's effect is large and repeats across emetogens, routes and intervals: emesis 4% vs 40% (oral, 18 h), 1/32 vs 20/34 (subcutaneous, 20 h), 13% vs 32% (oral, 2–2.5 h), and significantly less vomiting over 2 weeks in CKD cats (P <0.01). Versus the older antiemetics, the only randomised head-to-head found maropitant, ondansetron and metoclopramide indistinguishable, all ahead of saline. Nausea signs (lip-licking, sialorrhoea) were not reliably reduced in any trial even when vomiting stopped.

Watch out: The vs-control effects come mostly from challenge models in healthy cats; spontaneous acute vomiting in clinical patients is directly represented only by the CKD trial (chronic vomiting) and an uncontrolled 8-cat series. Whether maropitant beats metoclopramide or ondansetron for a vomiting cat in the clinic is untested — the honest claim is 'proven against no treatment; unproven against the alternatives'.

Synthesis of Martin-Flores M et al. PMID: 26534944; Martin-Flores M et al. PMID: 27172341; Quimby JM et al. PMID: 25336450; Gölgeli Bedir A et al. PMID: 39792081; Martin-Flores M et al. PMID: 27538868; Hickman MA et al. PMID: 18471143; Boukaache Y et al. PMID: 36589400. Registry IDs as on the individual cards.

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