POM-V Prescription Required

Somnipron 10 mg/ml Solution for Injection for Horses and Cattle

Active ingredient: Detomidine Hydrochloride

Form

Injection

Species

Cattle Horses

Manufacturer

Vetpharma Animal Health, S.L

VMD MA No.

32509/4022

What it's used for

For premedication before administration of injectable or inhalational anaesthetics.

Full indications, dosage and side effects ↓

View official SPC (PDF)

The prescription itself has a price. See what practices near you charge for a consultation and the written prescription fee.

Paying less for Detomidine Hydrochloride

1

Ask your vet for a written prescription

They must provide one on request. Under the CMA Order the fee is capped at £21 from 2027.
2

Fill it at a registered online retailer

The CMA found online pharmacies 50–60% cheaper than practice dispensing on common medicines — typically £200–£300 a year.

Your prescription rights → VMD register of retailers →

Prescription required

Your vet must provide a written prescription on request. You can then purchase from any licensed online retailer.

Clinical information

Somnipron 10 mg/ml Solution for Injection for Horses and Cattle — SPC Details

Source: VMD Summary of Product Characteristics (SPC). Last updated 27 Mar 2026.

For premedication before administration of injectable or inhalational
anaesthetics.

To be administered intramuscularly or by slow intravenous injection of
detomidine hydrochloride at a dose of 10–80 µg/kg depending on the degree
and duration of sedation and analgesia required. The effect is more rapid after
intravenous administration. To ensure a correct dosage, body weight should be
determined as accurately as possible.
AN: 04389/2024 & 04391/2024
Page 6 of 10Single use (horses and cattle)
Dose
ml/100 kgµg/kg
Effect
Duration
of effect
(hours)
Other effects
0.1–0.210–20Sedation0.5-1
0.2–0.420–40
Sedation and
analgesia
0.5–1
Slight
staggering
0.4–0.840–80
Deeper
sedation and
better
analgesia
0.5–2
Staggering,
sweating,
piloerection,
muscular
tremors
The onset of action occurs 2–5 min after i.v. injection. The full effect is seen 10–
15 min after i.v. injection. If necessary, detomidine hydrochloride can be
administered up to a total dose of 80 µg/kg.
The following dosing instructions show different possibilities for the combination
of detomidine hydrochloride. However, the simultaneous administration with
other drugs should always be based on a benefit-risk assessment by the
responsible veterinarian and it must be done taking into account the SPC of the
relevant veterinary medicinal products.
Combinations with detomidine to increase sedation or analgesia in a
standing horse
Detomidine hydrochloride 10–30 µg/kg i.v. in combination with either
•
•
•
Combinations with detomidine to increase sedation or analgesia in cattle
Detomidine hydrochloride 10-30 µg/kg i.v. in combination with
•
Combinations with detomidine for preanaesthetic sedation in the horse
The following anaesthetics can be used after detomidine hydrochloride
premedication (10–20 µg/kg) to achieve lateral recumbency and general
anaesthesia:
•
•
AN: 04389/2024 & 04391/2024
Page 7 of 10•
Administer the veterinary medicinal product prior to ketamine and allow sufficient
time for sedation to develop (5 minutes). Ketamine and the veterinary medicinal
product must therefore never be administered simultaneously in the same
syringe.
Combinations with detomidine and inhalation anaesthetics in the horse
Detomidine hydrochloride can be used as sedative premedicant (10–30 µg/kg)
before induction and maintenance of inhalation anaesthesia. Inhalation
anaesthetic is given to effect. The amount of inhalation anaesthetics required is
significantly reduced by premedication with detomidine.
Combination with detomidine to maintain injection anaesthesia (total
intravenous anaesthesia TIVA) in the horse
Detomidine can be used in combination with ketamine and guaifenesin for
maintaining total intravenous anaesthesia (TIVA).
The best-documented solution contains guaifenesin 50–100 mg/ml, detomidine
hydrochloride 20 µg/ml and ketamine 2 mg/ml. 1 g ketamine and 10 mg
detomidine hydrochloride are added to 500 ml of 5–10% guaifenesin;
anaesthesia is maintained by an infusion of 1 ml/kg/h.
Combinations with detomidine for induction and maintenance of general
anaesthesia in cattle
Detomidine hydrochloride 20 µg/kg (0.2 ml/100 kg) with
•
•
The effect of detomidine-ketamine lasts for 20–30 minutes, and the effect of
detomidine- thiopental for 10–20 minutes.

Do not use in animals with severe cardiac insufficiency, cardiac abnormalities,
pre-existing AV/SA block, severe respiratory disease, or severely impaired liver
or kidney function.
Do not use in combination with butorphanol in horses with colic without further
monitoring of the horse for signs of clinical deterioration.
Qualitative composition of
excipients and other
constituents
Quantitative composition if that
information is essentialfor proper
administration of the veterinary
medicinal product
Methyl parahydroxybenzoate (E
218)
1.0 mg
Sodium chlorideWater for injections
AN: 04389/2024 & 04391/2024
Page 2 of 10Do not use in conjunction with sympathomimetic amines or with intravenous
potentiated sulfonamides. Concurrent use with intravenous potentiated
sulfonamides may cause cardiac arrhythmia with a fatal outcome.
Do not use in cases of hypersensitivity to the active substance or to any of the
excipients.

Cattle
Very common
(>1 animal / 10 animals
treated):
Bradycardia, Hypertension (transient),
Hypotension (transient)
Hyperglycaemia
Urination
Penile prolapse (transient)
Common (1 to 10
animals / 100 animals
treated):
Ruminal tympany
, Hypersalivation (transient)
Ataxia, Muscle tremor
Uterine contraction
Nasal discharge
, Respiratory depression
(slight)
Hyperthermia, Hypothermia
Rare
(1 to 10 animals / 10 000
animals treated):
Arrhythmia
Increased sweating (transient)
Very rare
(<1 animal / 10 000
animals treated,
including isolated
reports):
Excitation
Heart block
Hyperventilation (slight)
AN: 04389/2024 & 04391/2024
A diuretic effect may be observed 45 to 60 minutes after treatment.
A partial, penis prolapse can occur.
Substances of this class inhibit ruminal and intestinal motility. Can cause a
mild bloat in cattle.
Mucus discharge from the nose may be seen because of continued lowering
of the head during sedation.
Causes changes in the respiratory rate.
Causes changes in the conductivity of cardiac muscle as evidenced by partial
atrioventricular and sinoatrial blocks
Horses
Very common
(>1 animal / 10 animals
treated):
Arrhythmia
, Bradycardia, Heart block
,
Hypertension (transient), Hypotension (transient)
Hyperglycaemia
Ataxia, Muscle tremor
Urination
Penile prolapse (transient)
, Uterine contraction
Increased sweating (transient), Piloerection
Hyperthermia, Hypothermia
Common (1 to 10
animals / 100 animals
treated):
Hypersalivation (transient)
Nasal discharge
Skin swelling
Rare
(1 to 10 animals / 10 000
animals treated):
Colic
Urticaria
Hyperventilation, Respiratory depression
Very rare
(<1 animal / 10 000
animals treated,
including isolated
reports):
Excitation
Hypersensitivity reaction
Causes changes in the conductivity of cardiac muscle as evidenced by partial
atrioventricular and sinoatrial blocks.
A diuretic effect may be observed 45 to 60 minutes after treatment.
A partial penis prolapse can occur in stallions and geldings.
Mucus discharges from the nose and oedema of the head and face may be
seen because of continued lowering of the head during sedation.
Substances of this class inhibit intestinal motility.
Mild adverse reactions have reportedly resolved uneventfully without treatment.
Adverse reactions should be treated symptomatically.
Reporting adverse events is important. It allows continuous safety monitoring of
a veterinary medicinal product. Reports should be sent, preferably via a
veterinarian, to either the marketing authorisation holder or its local
representative or the national competent authority via the national reporting
system. See the package leaflet for respective contact details.
AN: 04389/2024 & 04391/2024

None

Special precautions for safe use in the target species:
A benefit-risk assessment should be performed by the responsible veterinarian
prior to administration of the veterinary medicinal product to the following
categories of animals: those approaching or in endotoxic or traumatic shock,
animals with dehydration or respiratory disease, horses with pre-existing
bradycardia, fever, or under extreme stress. During prolonged sedation, monitor
body temperature and, if necessary, take measures to maintain normal body
temperature.
When the veterinary medicinal product is administered, the animal should be
allowed to rest in a maximally quiet place. Before any procedure is initiated, the
sedation should be allowed to reach its peak effect (approximately 10–15
minutes following IV administration.). At the onset of the effect, it is to be noted
that the animal may stagger and lower its head. Cattle and especially young
animals may become recumbent when high detomidine doses are used. In order
to minimize the risk of injuries, tympany or aspiration, measures such as
selecting a suitable environment for treatment, and lowering the head and neck
should be taken.
For horses, fasting for 12 hours before planned anaesthesia is recommended.
Food and water should be withheld until the sedative effect of the veterinary
medicinal product has worn off.
For painful procedures, the veterinary medicinal product should be combined
with (an) other analgesic agent(s).
Special precautions to be taken by the person administering the veterinary
medicinal product to animals:
Some horses, although apparently deeply sedated, may still respond to external
stimuli. Routine safety measures should be employed to protect practitioners and
handlers.
Detomidine is an alpha-2 adrenoceptor agonist, which may cause sedation,
somnolence, decreased blood pressure and decreased heart rate in humans.
In the case of accidental ingestion or self-injection, seek medical advice
immediately and show the package leaflet or the label to the physician, but DO
NOT DRIVE as sedation and changes in blood pressure may occur.
AN: 04389/2024 & 04391/2024
Avoid skin, eye, or mucosal contact.
Immediately after exposure, wash the exposed skin with large amounts of fresh
water.
Remove contaminated clothes that are in direct contact with skin.
In the case of accidental contact of the veterinary medicinal product with eyes,
rinse with large amounts of fresh water. If symptoms occur, seek the advice of a
doctor.
If pregnant women handle the veterinary medicinal product, special caution
should be observed not to self-inject as uterine contractions and decreased foetal
blood pressure may occur after accidental systemic exposure.
To the physician:
Detomidine hydrochloride is an alpha-2 adrenoreceptor agonist. Symptoms after
absorption may involve clinical effects including dose dependent sedation,
respiratory depression, bradycardia, hypotension, a dry mouth and
hyperglycaemia. Ventricular arrhythmias have also been reported. Respiratory
and haemodynamic symptoms should be treated symptomatically.
Special precautions for the protection of the environment:
Not applicable

Detomidine has an additive-synergistic effect with other sedatives, anaesthetics,
hypnotics and analgesics and therefore, an appropriate dose adjustment may be
needed.
When the veterinary medicinal product is used as a premedication prior to
general anaesthesia, the veterinary medicinal product may delay onset of
induction.
Detomidine should not be used in conjunction with sympathomimetic amines
such as adrenaline, dobutamine and ephedrine, as these agents counteract the
sedative effect of detomidine, except in the case of anaesthetic incidents.
For intravenous potentiated sulfonamides, see section 3.3.‘Contraindications’.

Keep the vial in the outer carton in order to protect from light.
Do not refrigerate or freeze.

Horses and cattle
Meat and offal: 2 days
Milk: 12 hours

This information is sourced from the official Summary of Product Characteristics (SPC) published by the Veterinary Medicines Directorate (VMD). It is provided for informational purposes only and does not replace professional veterinary advice. Always consult your vet before administering any medication.