# Romifidine: veterinary dose and monograph

> Romifidine is a veterinary sedative or anaesthetic agent. An alpha-2 adrenergic agonist sedative/analgesic developed mainly for HORSES (Sedivet) — it produces reliable standing sedation for clinical procedures with notably LESS ATAXIA / head-lowering than xylazine or detomidine at equivalent… Indications include standing sedation in horses for clinical/diagnostic and minor procedures (less ataxia); premedication / component of balanced anaesthesia (horses); sedation/restraint with reduced head-lowering for dental/standing work. This monograph lists 7 reference doses for dogs, cats, cattle and horses, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/romifidine · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Sedative / anaesthetic
- **Also known as:** Sedivet, Romifidine HCl
- **Species with doses:** Dogs, Cats, Cattle and Horses
- **General dose range:** 0.04–0.12 mg/kg IV single dose (reversible) — check the species tables for the indication
- **Routes:** IV, IM, Epidural
- **Last reviewed:** 1 October 2026

## Indications

- Standing sedation in horses for clinical/diagnostic and minor procedures (less ataxia)
- Premedication / component of balanced anaesthesia (horses)
- Sedation/restraint with reduced head-lowering for dental/standing work
- Sedation in cattle (off-label) and, less commonly, dogs

## Romifidine dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Dogs

*Romifidine doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / pre-anaesthetic | 0.04–0.12 mg/kg | IV | single dose | — |
| Analgesic adjunct (low dose) | 0.01–0.02 mg/kg | IM | single dose | — |

- Sedation / pre-anaesthetic: Plumb’s p.1048 (Romydis label): 40–120 µg/kg IV, IM or SC — IV sedation within about 5 min; IM/SC onset about 30 min and shallower. Induce anaesthesia about 10 min after IV (10–15 min after IM/SC). Reverse with atipamezole (200 µg/kg IM reverses 120 µg/kg). Papich 5e: small-animal doses not established. (40–120 µg/kg = 0.04–0.12 mg/kg.)
- Analgesic adjunct (low dose): Plumb’s p.1048 (Lamont & Tranquilli 2002): 10–20 µg/kg IM or SC in exercise-tolerant dogs without heart disease; may combine with an anticholinergic.

### Cats

*Romifidine doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / pre-anaesthetic | 0.2–0.4 mg/kg | IM | single dose | — |
| Analgesic adjunct (low dose) | 0.02–0.04 mg/kg | IM | single dose | — |

- Sedation / pre-anaesthetic: Plumb’s p.1048 (Romydis label): 200–400 µg/kg IV or IM; 200 µg/kg IM sedates in about 10 min for about 60 min. Pre-anaesthetic: 200 µg/kg IM 10–15 min before ketamine 10 mg/kg IM gives up to 30 min surgical anaesthesia (400 µg/kg extends it). Reverse with atipamezole IM (400 µg/kg reverses 400 µg/kg). (200–400 µg/kg = 0.2–0.4 mg/kg.)
- Analgesic adjunct (low dose): Plumb’s p.1048 (Lamont & Tranquilli 2002): 20–40 µg/kg IM or IV in healthy cats without heart disease.

### Cattle

*Romifidine doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Epidural analgesia (flank laparotomy) | 0.05 mg/kg | Epidural | single dose (with morphine 0.1 mg/kg) | — | Withdrawal NOT established — treat as extra-label |

- Epidural analgesia (flank laparotomy): Plumb’s p.1048 (Anderson 2006): romifidine 50 µg/kg plus morphine 0.1 mg/kg epidurally; analgesia up to 12 h. Not FDA-approved in food animals — obtain a FARAD withdrawal. Plumb’s 10e p.1130 gives the same 50 µg/kg + morphine 0.1 mg/kg epidural (analgesia 12 h maximum) and notes epidural romifidine alone at 30–50 µg/kg in dairy cows caused dose-dependent sedation (deep at 50 µg/kg). No systemic sedative dose for cattle in Papich 5e or Plumb’s 10e.

### Horses

*Romifidine doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Standing sedation | 0.04–0.12 mg/kg | IV | single dose | — |
| Pre-anaesthetic | 0.1 mg/kg | IV | single dose | — |

- Standing sedation: Papich 5e and Plumb’s p.1048 (Sedivet label): 40–120 µg/kg IV slowly once (0.4–1.2 mL per 100 kg of 10 mg/mL); sedation is dose-dependent, onset 0.5–5 min, subsiding over 2–4 h; analgesia is shorter than sedation. Often combined with butorphanol. (40–120 µg/kg = 0.04–0.12 mg/kg.)
- Pre-anaesthetic: Papich 5e and Plumb’s p.1048 (label): 100 µg/kg as a slow single IV injection; induce once maximal sedation is reached. Romifidine is anaesthetic-sparing — reduce induction doses. (100 µg/kg = 0.1 mg/kg.)

### Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

*Romifidine doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Epidural analgesia (flank laparotomy) | 0.05 mg/kg | Epidural | single dose (with morphine 0.1 mg/kg) | — | Withdrawal NOT established — treat as extra-label |

- Epidural analgesia (flank laparotomy): Plumb’s p.1048 (Anderson 2006): romifidine 50 µg/kg plus morphine 0.1 mg/kg epidurally; analgesia up to 12 h. Not FDA-approved in food animals — obtain a FARAD withdrawal. Plumb’s 10e p.1130 gives the same 50 µg/kg + morphine 0.1 mg/kg epidural (analgesia 12 h maximum) and notes epidural romifidine alone at 30–50 µg/kg in dairy cows caused dose-dependent sedation (deep at 50 µg/kg). No systemic sedative dose for cattle in Papich 5e or Plumb’s 10e.

## Contraindications

Significant cardiovascular disease (bradyarrhythmia/AV block), shock/hypovolaemia, and late pregnancy (uterine/fetal effects). Respiratory compromise. Use reduced doses in debilitated animals. Concurrent IV potentiated sulfonamides in horses (alpha-2 agonist + IV TMP-sulfa has caused fatal arrhythmias). Known hypersensitivity.

## Species-specific warnings

> **Caution:** Cattle: Cattle are highly alpha-2 sensitive — use much lower doses than horses; off-label.

> **Caution:** Horses: Avoid concurrent IV trimethoprim-sulfonamide (alpha-2 + IV TMP-sulfa has caused fatal arrhythmias in horses).

## Adverse effects

- Bradycardia and AV block; initial hypertension then hypotension
- Reduced cardiac output, ataxia (less than xylazine/detomidine), sweating
- Diuresis, hyperglycaemia, reduced GI motility
- Muscle relaxation; penile prolapse in stallions (transient)

## Drug interactions

- Other sedatives/anaesthetics/opioids: additive sedation and cardiorespiratory depression (often combined deliberately, e.g. with butorphanol)
- IV potentiated sulfonamides (TMP-sulfa) in horses: fatal arrhythmias reported with alpha-2 agonists — avoid concurrent IV use
- Atipamezole: reversal agent
- Anticholinergics: variable (may worsen hypertension) — use judiciously for bradycardia

## Pregnancy and lactation

Avoid in late pregnancy (alpha-2 effects on uterine tone/fetus).

## Monitoring

- Heart rate/rhythm (bradycardia/AV block), mucous membranes, blood pressure
- Depth/duration of sedation; respiratory rate
- Avoid concurrent IV TMP-sulfa in horses
- Recovery quality (reverse with atipamezole if needed)

## Toxicity and overdose

Overdose deepens the alpha-2 cardiovascular effects — profound bradycardia/AV block, hypotension, marked CNS and respiratory depression. Generally survivable with reversal because the effect is specifically antagonisable.

Management: Antidote: ATIPAMEZOLE reverses sedation and cardiovascular effects (dose per product/clinical judgement). Support ventilation/oxygenation; treat clinically significant bradycardia per anaesthetic judgement; IV fluids for hypotension after the vasoconstrictive phase.

## Clinical pearls

- The alpha-2 of choice for many standing equine procedures — similar sedation to xylazine/detomidine but with LESS ataxia and head-lowering (the horse stays steadier/head higher)
- Longer-acting than xylazine; commonly combined with butorphanol for standing work
- Class cardiovascular effects apply (bradycardia, AV block) — and atipamezole reverses it
- In horses, do NOT give IV potentiated sulfonamides concurrently with alpha-2 agonists (fatal arrhythmias reported)

## Mechanism of action

A selective alpha-2 adrenoceptor agonist: central (brainstem/locus coeruleus) alpha-2 stimulation reduces noradrenaline release → sedation and analgesia, while peripheral vascular alpha-2 receptors cause initial vasoconstriction (transient hypertension with reflex bradycardia) followed by reduced sympathetic tone. Its receptor/pharmacokinetic profile yields sedation with comparatively less ataxia and head-lowering than other equine alpha-2 agonists.

## Formulations and products

- Injection 10 mg/mL (Sedivet)
- Sedivet (Boehringer Ingelheim) — 10 mg/mL, Injection

## Storage

Injection: 15–30 °C, protect from light; do not freeze.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

## Other sedatives and anaesthetics

- [Midazolam](https://vetmasterji.com/drugs/midazolam)
- [Pentobarbital (Pentobarbitone)](https://vetmasterji.com/drugs/pentobarbital)
- [Phenobarbital](https://vetmasterji.com/drugs/phenobarbital)
- [Propofol](https://vetmasterji.com/drugs/propofol)
- [Sevoflurane](https://vetmasterji.com/drugs/sevoflurane)
- [Thiopental Sodium](https://vetmasterji.com/drugs/thiopental)
- [Tiletamine–Zolazepam](https://vetmasterji.com/drugs/tiletamine-zolazepam)
- [Trazodone](https://vetmasterji.com/drugs/trazodone)

## Frequently asked questions

### What is the dose of Romifidine for dogs?

Reference doses for Romifidine in dogs: 0.04–0.12 mg/kg IV single dose (Sedation / pre-anaesthetic); 0.01–0.02 mg/kg IM single dose (Analgesic adjunct (low dose)). Confirm against the label and the patient before use.

### What is the dose of Romifidine for cats?

Reference doses for Romifidine in cats: 0.2–0.4 mg/kg IM single dose (Sedation / pre-anaesthetic); 0.02–0.04 mg/kg IM single dose (Analgesic adjunct (low dose)). Confirm against the label and the patient before use.

### What is the dose of Romifidine for cattle?

Reference doses for Romifidine in cattle: 0.05 mg/kg Epidural single dose (with morphine 0.1 mg/kg) (Epidural analgesia (flank laparotomy)). Confirm against the label and the patient before use.

### What is the withdrawal period for Romifidine?

Cattle, Epidural (Epidural analgesia (flank laparotomy)): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Romifidine not be used?

Significant cardiovascular disease (bradyarrhythmia/AV block), shock/hypovolaemia, and late pregnancy (uterine/fetal effects). Respiratory compromise. Use reduced doses in debilitated animals. Concurrent IV potentiated sulfonamides in horses (alpha-2 agonist + IV TMP-sulfa has caused fatal arrhythmias). Known hypersensitivity.

### What are the side effects of Romifidine in animals?

Bradycardia and AV block; initial hypertension then hypotension; Reduced cardiac output, ataxia (less than xylazine/detomidine), sweating; Diuresis, hyperglycaemia, reduced GI motility; Muscle relaxation; penile prolapse in stallions (transient).

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.