POM-V Prescription Required

Hidrocol, 4000000 IU/ml Solution for Use in Drinking Water/Milk

Active ingredient: Colistin Sulphate

Form

Solution

Species

Cattle Chickens Pigs Sheep Turkeys

Manufacturer

SP Veterinaria, S.A.

VMD MA No.

36967/4005

What it's used for

susceptible to colistin. In the case of metaphylaxis, the presence of the disease in the group / flock must be established before the product is used.

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 Colistin Sulphate

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

Hidrocol, 4000000 IU/ml Solution for Use in Drinking Water/Milk — SPC Details

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

susceptible to colistin.
In the case of metaphylaxis, the presence of the disease in the group / flock must be
established before the product is used.

In drinking water / milk use.
Calves, lambs, pigs:100 000 IU of colistin sulfate per kg body weight daily for 3-5
consecutive days in drinking water or milk (replacer) in calves, equivalent to 0.25 mL
of the concentrate solution per 10 kg body weight per day for 3-5 days.
Chickens and turkeys: 75 000 IU of colistin sulfate per kg body weight daily for 3-5
consecutive days in drinking water, equivalent to 18.75 mL of the concentrate
solution per Ton of body weight per day for 3-5 days.
Duration of treatment should be limited to the minimum time necessary for the
treatment of the disease.
AN: 00304/2025 & 00307/2025
Any medicated water which is not consumed within 24 hours should be discarded.
Any medicated milk which is not consumed within 3 hours should be discarded.
Direct oral administration to individual animals
The recommended daily dose should be divided into two if the product is to be
administered directly into the mouth of the animal.
Prior to direct oral administration, the product should be diluted with a volume of
drinking water equivalent to 2 x the volume of product concentrate to be
administered.
Administration via drinking water
The intake of medicated water depends on the clinical condition of the animals. In
order to obtain the correct dosage the concentration of colistin sulfate has to be
adjusted accordingly. Carefully calculate the average body weight to be treated and
the average daily water consumption before each treatment.
Water uptake should be monitored at frequent intervals.
Medicated water should be made every day, immediately prior to provision.
The medicated water should be the only source of drinking water for the animals for
the entire duration of the treatment period.
With the following formula, we can calculate an exact dosage:
1 mL of veterinary
medicinal product / kg
bodyweight per day
x
average bodyweight
(kg) of animals to be
treated
Average daily water intake (l/animal)
=
mL of veterinary
medicinal product per
litre of drinking water
• Administration without a dosing pump:
The treatment is distributed in a tank over a period of 24 hours, for 3-5 consecutive
days.
The product is added to a volume of the drinking water corresponding to the volume
consumed by the animals over the treatment period (24 hours) to achieve a dose of
100 000 IU of colistin sulfate per kg body weight for pigs, lambs and calves and 75
000 IU of colistin sulfate per kg body weight for chickens and turkeys.
• Administration via a dosing pump:
The treatment is distributed over a period of 24 hours, for 3-5 consecutive days.
A dosing pump is used to add a stock solution at a pre-determined concentration to
the drinking water.

Do not use in cases of hypersensitivity to the active substance or to any of the
excipients.
Do not use in cases of resistance to polymyxins.
Do not use in horses, particularly in foals, since colistin sulfate, due to a shift in the
gastrointestinal microflora balance could lead to the development of antimicrobial
associated colitis (Colitis X), typically associated with , which may
be fatal.
AN: 00304/2025 & 00307/2025

Cattle (calves), sheep (lambs), pigs, chickens and turkeys.
None known.
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 the national competent authority via the
national reporting system. See the package leaflet for respective contact details.

Colistin sulfate exerts concentration-dependent activity against Gram-negative
bacteria. Following oral administration high concentrations are achieved in the
gastrointestinal tract, i.e. the target site, due to the poor absorption of the substance.
These factors indicate that a longer duration of treatment than the one indicated in
section 3.9, leading to unnecessary exposure, is not recommended.
As an adjunct to treatment, good management and hygiene practices should be
introduced in order to reduce the risk of infection and to control the potential build up
of resistance.
There is cross-resistance between colistin sulfate and polymyxin B.

Special precautions for safe use in the target species:
Use of the product should be based on identification and susceptibility testing of the
target pathogen(s). If this is not possible, therapy should be based on
epidemiological information and knowledge of susceptibility of the target pathogens
at farm level, or at local/regional level. Use of the product should be in accordance
with official, national and regional antimicrobial policies.
Colistin sulfate is a last resort drug in human medicine for treatment of infections
caused by certain multi-drug resistant bacteria. In order to minimise any potential risk
associated with widespread use of colistin sulfate, its use should be limited to
treatment or treatment and metaphylaxis of diseases, and should not be used for
prophylaxis.
Whenever possible, colistin sulfate should only be used based on susceptibility
testing.
An antibiotic with a lower risk of antimicrobial resistance selection (lower AMEG
category) should be used for first line treatment where susceptibility testing suggests
the likely efficacy of this approach.
Use of the product deviating from the instructions given in the SPC may lead to
treatment failures and increase the prevalence of bacteria resistant to colistin sulfate.
In the case of newborn animals and animals with severe gastrointestinal and renal
disorders, systemic exposure to colistin sulfate may be increased. As a result, neuro-
and nephrotoxic effects may occur.
Do not use colistin sulfate as a substitute for good management practices.
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
People with known hypersensitivity to polymyxins, such as colistin sulfate, should
avoid contact with the veterinary medicinal product.
Avoid direct contact with skin and eyes while handling the product. Personal
protective equipment consisting of gloves and protective goggles must be worn while
handling and dosing the product.
Do not eat, drink or smoke while handling the product.
Wash splashes from skin immediately with soap and plenty of water.
In case of accidental eye exposure, wash with plenty of water and seek medical
attention immediately and show the package leaflet or the label to the physician.
AN: 00304/2025 & 00307/2025
If you develop symptoms following exposure such as skin rash, you should seek
medical advice and show the physician this warning. Swelling of the face, lips or eyes
or difficulty in breathing are more serious symptoms and require urgent medical
attention.
Wash hands after use.
Special precautions for the protection of the environment:
Not applicable.

After oral administration of colistin sulfate interaction with anaesthetics (curarimimetic
agents) and myorelaxants may not be excluded in individual cases. The combination
with aminoglycosides and levamisole should be avoided. The effects of colistin
sulfate may be antagonized by binary cations (iron, calcium, magnesium) and by
unsaturated fatty acids and polyphosphates.

Do not store above 25 C.
Protect from light.

Cattle (calves), sheep (lambs) and pigs:
-
Chickens and turkeys:
-
-

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.