Phenoxypen Water Soluble Powder, 325 mg/g powder for oral solution for chickens

Ireland - English - HPRA (Health Products Regulatory Authority)

Active ingredient:
Available from:
Dopharma Research B.V.
ATC code:
INN (International Name):
325 milligram(s)/gram
Pharmaceutical form:
Powder for oral solution
Prescription type:
POM: Prescription Only Medicine as defined in relevant national legislation
Therapeutic group:
Therapeutic area:
Therapeutic indications:
Authorization status:
Authorization number:
Authorization date:

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Health Products Regulatory Authority

09 April 2020


Page 1 of 4

Summary of Product Characteristics


Phenoxypen Water Soluble Powder, 325 mg/g powder for oral solution for chickens


Per gram:

Active substance


293 mg

equivalent to potassium phenoxymethylpenicillin

325 mg


For the full list of excipients, see section 6.1.


Powder for oral solution. White to off-white powder.


4.1 Target Species


4.2 Indications for use, specifying the target species

Prevention of mortality at a group level from necrotic enteritis in chickens caused by Clostridium perfringens susceptible to


4.3 Contraindications

Do not use in cases of hypersensitivity to the active substance.

4.4 Special warnings for each target species

The administration of the product may lead to an increase in medicated water consumption.

4.5 Special precautions for use

Special precautions for use in animals

Use of the product should be based on susceptibility testing of the bacteria isolated from chickens that have already died on

the farm.

The product should not be used to compensate for poor hygiene and management of the chicken houses.

Special precautions to be taken by the person administering the veterinary medicinal product to animals

Phenoxymethylpenicillin may cause hypersensitivity reactions after injection, inhalation, oral ingestion, skin or eye contact.

Hypersensitivity to phenoxymethylpenicillin may lead to cross-sensitivity to other penicillins and cephalosporins, and vice versa.

Allergic reactions caused by these substances can sometimes be serious.

In case of accidental ingestion or serious symptoms of hypersensitivity reactions such as skin rash following exposure, swelling

of the face, lips or eyes or difficulty with breathing, seek medical advice immediately and show the package leaflet to the


People with known hypersensitivity to penicillins or cephalosporins should avoid contact with the product. In case of

development of hypersensitivity symptoms following exposure to the product, all further contact with the product (and other

medicines containing other penicillins or cephalosporins) should be avoided.

Health Products Regulatory Authority

09 April 2020


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Handle this product with great care to avoid exposure, taking all recommended precautions. Wear protective clothing,

impervious gloves and either a disposable half mask respirator conforming to European Standard EN149 or a non-disposable

respirator conforming to European Standard EN140 with a filter to EN 143 when mixing and handling the product. Wash hands

immediately after handling the product.

4.6 Adverse reactions (frequency and seriousness)

Although no adverse reactions have been seen after the administration of the product, penicillins may cause vomiting,

diarrhoea and alter gut flora with selecting resistant bacteria.

4.7 Use during pregnancy, lactation or lay

Studies in laboratory animals and humans have not produced any evidence of effects on reproductive function or foetal


4.8 Interaction with other medicinal products and other forms of interactions

Do not combine with bacteriostatic antibiotics.

4.9 Amounts to be administered and administration route

13.5 – 20 mg phenoxymethylpenicillin per kg of body weight per day,

corresponding with, 46 – 68 mg of the product per kg of body weight per day,

for 5 days.

Method of administration: oral use, dissolve in drinking water and use within 12 hours.

The maximum solubility is 250 g of the product per litre of drinking water.

The following calculation should be made to determine the quantity in gram of the product to be added in 1000 litres of water:

In dispensing the weight of the product to be used, the use of calibrated weighing equipment is recommended.

Taking into account that sick animals may drink less, it is recommended to start therapy with the higher dose, to compensate

for a possible lower intake of medicated water.

To ensure correct dosage, the body weight of the animals should be determined as accurately as possible to avoid


No other source of drinking water should be available during the medication period.

In cases of altered drinking water consumption in poultry, the concentration should be adjusted so that the recommended

dosage is achieved.

4.10 Overdose (symptoms, emergency procedures, antidotes), if necessary

Phenoxymethylpenicillin has a high therapeutic index. The administration of the medicated drinking water at two and five times

the recommended therapeutic dose for twice the recommended duration of treatment did not reveal any adverse effects. In

some individuals, administration of five times the recommended therapeutic dose for twice the recommended duration of

treatment led to an increase in water consumption, a decrease in feed intake and watery faeces.

Health Products Regulatory Authority

09 April 2020


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4.11 Withdrawal period(s)

Meat and offal: 2 days.

Eggs: zero days


Pharmacotherapeutic group: Beta-lactam antibacterials, penicillins

ATCvet-code: QJ01CE02

5.1 Pharmacodynamic properties

Phenoxymethylpenicillin is a narrow-spectrum penicillin with activity mainly against gram-positive bacteria.

Phenoxymethylpenicillin, as all other penicillins, exerts a bactericidal action on bacteria during the stage of active multiplication.

It forms an irreversible binding to penicillin-binding-proteins (PBPs), enzymes that facilitate the formation of cross-links of

peptidoglycan chains in the synthesis of the bacterial cell wall. This results in abnormal cell growth and cytolysis of the cell.

Phenoxymethylpenicillin is an acid-stable derivate of benzylpenicillin and has a largely comparable spectrum of activity.

Development of resistance is mainly based on the formation of beta-lactamase, an enzyme that breaks open the beta-lactam

ring, rendering the antibiotic ineffective. Cross resistance exists between phenoxymethylpenicillin and other beta-lactam


Minimum Inhibitory Concentrations (MICs) of phenoxymethylpenicillin were determined against Clostridium perfringens

isolates from clinical cases of necrotic enteritis in chickens during 1998 and 1999. The MIC for C. perfringens isolated from

faeces, liver and caecum samples were < 0.01 – 0.05 μg/ml.

5.2 Pharmacokinetic particulars

The most important advantage of phenoxymethylpenicillin in comparison with penicillin G is that it is more stable in an acid

environment and it is therefore better absorbed from the gastrointestinal tract.

Following oral use, phenoxymethylpenicillin for the most part escapes decomposition by gastric juices, as it is stable at a low

Phenoxymethylpenicillin is well distributed over most of the tissues, leading to a high concentration in the kidneys and the liver.

Phenoxymethylpenicillin is partially decomposed in the gastrointestinal tract. A small portion of the absorbed amount is

metabolised in the body. For the most part, phenoxymethylpenicillin is excreted in unaltered active form in urine and faeces.

Following a single administration of the product in poultry at a dose of 15 mg of phenoxymethylpenicillin potassium/kg

bodyweight by oral gavage, maximum plasma concentrations of 0.40 ± 0.15 mg/l are achieved within 1.7 ± 1.0 hours after

administration. Phenoxymethylpenicillin is well absorbed and has an absolute bioavailability of 69%.


6.1 List of excipients

Lactose monohydrate

6.2 Major incompatibilities

Do not mix with other veterinary medicinal products.

Contact of penicillin containing solutions with metals and the use of metal systems for their administration is known to

adversely influence penicillin stability. Therefore such systems should be avoided and they should not be used for the storage

of solutions.

Health Products Regulatory Authority

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6.3 Shelf-life

Shelf life of the veterinary medicinal product as packaged for sale:

- Securitainer; 3 years.

- Composite can: 3 years.

- Bucket: 2 years.

Shelf life after first opening the immediate packaging: 3 months.

Shelf life after reconstitution in drinking water according to directions: 12 hours.

6.4 Special precautions for storage

Store below 25°C.

Do not refrigerate or freeze.

Protect from frost.

Store in the original package.

6.5 Nature and composition of immediate packaging

- Securitainer: white PP cylindrical container, with white HDPE/LDPE closure, with thumb-tab for opening. This type of container

has two different sizes (650 ml, 1875 ml) with a content of 250 g, 1000 g product respectively.

- Composite can: three-layered rectangular container, which consists of a cardboard base with an inner lining of

aluminium-paper and with label on the outside. This type of container has a content of 1 kg of product.

- Bucket: white polypropylene bucket provided with a polypropylene lid. The bucket contains 1, 2.5 or 5 kg of product.

Not all pack sizes may be marketed.

6.6 Special precautions for the disposal of unused veterinary medicinal products or waste materials derived from the

use of such products

Any unused veterinary medicinal product or waste materials derived from such veterinary medicinal product should be

disposed of in accordance with local requirements.


Dopharma Research B.V.

Zalmweg 24

4941 VX Raamsdonksveer





June 2011


April 2020

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