Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Benzylpenicillin benzathine may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
for This medicine contains benzylpenicillin benzathine, which is one of a group of medicines known as penicillins ("antibiotics"). Antibiotics are used to kill the bacteria (germs) which cause infections. Benzylpenicillin benzathine is used for the treatment of:
If allergic symptoms occur (e.g. skin rash, itching, shortness of breath), tell a doctor immediately. Before treatment, a hypersensitivity test should be performed if possible. If an allergic reaction occurs, your doctor will stop your treatment and, if necessary, start appropriate therapy. As a possible cross-allergy should be considered in patients with hypersensitivity to cephalosporins, please tell your doctor if you have already had a previous allergic reaction to certain antibiotics (cephalosporins). If you have already been diagnosed with an allergy and/or allergic asthma or hay fever, you should tell your doctor. Severe immediate allergic reactions are possible even when the drug is administered for the first time. Based on general principles, in some cases, you will remain under observation for at least half an hour after the medicine has been administered in case an acute allergic reaction should occur. If an allergy occurs, the doctor will take appropriate measures. Treatment with benzylpenicillin benzathine must be stopped immediately. When treating syphilis, a reaction to the bacterial toxins may occur, which lasts up to several days (Jarisch-Herxheimer reaction, see section 4). Typical symptoms are sudden fever (sometimes with chills), pale skin; followed by skin redness, headache, painful muscles and joints or tiredness. To suppress or alleviate a Jarisch-Herxheimer reaction, your doctor will start appropriate therapy. Dose adjustments are necessary in patients with impaired kidney function and in patients with impaired liver function (see section 3). In long-term treatment (more than a single dose), your doctor may arrange for checks on your blood count and liver and kidney function tests. Please make sure that you attend the check-ups prescribed by the doctor. As with other antibiotics, therapy with benzylpenicillin benzathine may also lead to the overgrowth of non-susceptible germs. Contact your doctor if you get, for example, a fungal infection. During treatment with antibiotics, including benzylpenicillin benzathine, diarrhoea may occur, even several weeks after you stopped your therapy. In case of severe or persistent diarrhoea, or if you notice that your stools contain blood or mucus, contact your doctor immediately. The therapy with benzylpenicillin benzathine must be stopped immediately, as it can be life-threatening. Do not take any medications which stop or slow down the bowel movements. If neurological involvement cannot be ruled out in patients with congenital syphilis, forms of penicillin that reach a higher level in cerebrospinal fluid should be used. Decreased elimination of povidone (one excipient included in this drug) should be considered in case of impairment of kidney function. It cannot be excluded that in very rare cases an accumulation of povidone or a local deposition and formation of granulomas (inflammation) may occur, which may be confused with tumours. An effect on laboratory test results should also be considered (see also section 4). Other medicines and benzylpenicillin benzathine Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines. Caution should be exercised when administering benzylpenicillin benzathine at the same time as the following medicines:
–
anticoagulants: medicines used to thin the blood.
Pregnancy and breast-feeding If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before this medicine is used. Pregnancy Benzylpenicillin benzathine can be used during pregnancy after appropriate diagnosis and careful consideration of the benefits and risks by the prescribing doctor. Breast-feeding Small amounts of benzylpenicillin benzathine, the active substance, pass into breast milk. Although no side effects have been reported to date in young infants fed on breast milk, the possibility of sensitisation or interference with the gut flora must nevertheless be considered. In the case of diarrhoea, candidiasis (fungal infection) or rash in the child, immediately ask your doctor for advice, because these disorders in the child could be due to benzylpenicillin benzathine. In young infants also being fed on baby food, mothers receiving benzylpenicillin benzathine should express and discard their breast milk. They can start breast-feeding again 24 hours after completion of treatment. Driving and using machines This medicine can impair responsiveness and the ability to drive. Due to the occurrence of possible serious side effects (e.g. anaphylactic shock with collapse and allergic-like reactions (e.g. stomach upsets), see section 4), benzylpenicillin benzathine can have a major influence on the ability to drive and use machines. Benzylpenicillin benzathine contains phospholipids from the soya lecithin and sodium This medicine contains phospholipids from soya lecithin. If you are allergic to peanut or soya, do not use this medicinal product. This medicine contains less than 1 mmol sodium (23 mg) per vial 1.2 Million I.U. and 2.4 Million I.U., that is to say essentially 'sodium-free'.
Benzylpenicillin benzathine is administered by your doctor, nurse or pharmacist. The recommended dose is: General treatment:
• –
1.2 Million I.U. 1.2 Million I.U. 0.6 Million I.U. Single dose
2.4 Million I.U. 50,000 IU per kg body weight, but not more than 2.4 Million I.U. Duration of treatment: Single dose (If clinical symptoms return or laboratory findings remain strongly positive, treatment should be repeated.) Late-stage syphilis (latent seropositive syphilis) Adults and adolescents: 2.4 Million I.U.
• –
Children:
50,000 IU per kg body weight, but not more than 2.4 Million I.U. Duration of treatment: Once weekly for 3 weeks Treatment of congenital syphilis (without neurological involvement) Newborns and infants: 50,000 IU / kg body weight Duration of treatment: Single dose
Treatment of tropical infectious skin diseases (yaws, pinta):
Like all medicines, this medicine can cause side effects, although not everybody gets them. Common side effects (may affect up to 1 in 10 people)
•
Changes in certain test and investigation results performed by your doctor.
Uncommon side effects (may affect up to 1 in 100 people)
benzylpenicillin benzathine Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date which is stated on the label and carton after "EXP". The expiry date refers to the last day of that month.
This medicine does not require any special storage conditions. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
What benzylpenicillin benzathine contains The active substance is benzylpenicillin benzathine. The other ingredients are: soya lecithin; polysorbate 80; carmellose sodium; sodium citrate, anhydrous; and povidone. What benzylpenicillin benzathine looks like and contents of the pack Powder in a glass vial for suspension for injection in a carton. Pack of 1 vial. Marketing Authorisation Holder Brancaster Pharma Limited Church House, 48 Church Street Reigate Surrey, RH2 0SN United Kingdom Manufacturer Haupt Pharma Latina Strada Statale 156 dei Monti Lepini 04100 Borgo San Michele LT – Italy This leaflet was last revised in 11/2025. Advice/medical education Antibiotics are used to cure bacterial infections. They are ineffective against viral infections. If your doctor has prescribed antibiotics, you need them precisely for your current illness. Despite antibiotics, some bacteria may survive or grow. This phenomenon is called resistance: some antibiotic treatments become ineffective. Misuse of antibiotics increases resistance. You may even help bacteria become resistant and therefore delay your cure or decrease antibiotic efficacy if you do not respect the appropriate:
Method of administration The preparation is strictly for intramuscular injection (see SmPC). The injection must not be administered into tissue with reduced perfusion (see SmPC). This medicine should be administered by deep intramuscular injection into the upper, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field, with the needle pointing towards the iliac crest or according to von Hochstetter's method. The puncture should be as vertical to the skin surface as possible and the injection as far away from major vessels as possible. In all events, aspiration must be performed prior to the injection. If aspiration of blood or pain occurs during the injection, it must be discontinued. In children, the mid-lateral thigh muscles (quadriceps femoris) are recommended as an injection site. The deltoid muscle is only suitable if it is well formed; in this case, attention must be paid to the radial nerve. In infants and young children, the peripheral area of the upper outer quadrant of the gluteal region should be used as the area for injection only in exceptional cases (e.g. widespread burns), in order to avoid sciatic nerve lesions. The injection should be given as slowly as possible and only with the application of low pressure. "Rubbing" after the injection should be avoided. Clinical practice guidelines recommend the reconstitution of benzathine benzylpenicillin with local anaesthetics, such as 1% Lidocaine Injection BP, to reduce pain at the injection site. Users should follow local clinical protocols. Incompatibilities Data on compatibility are available with water for injections and lidocaine. Shelf-life after reconstitution The medicine should be used immediately after reconstitution. Special precautions for disposal and other handling The suspension must be prepared aseptically. Studies on numerous formulations of benzylpenicillin benzathine have identified an issue that aggregation of particles in the reconstituted suspension occurs in a small proportion of samples tested. Difficulty with reconstitution has been reported with Benzylpenicillin benzathine 2.4 Million I.U. powder for suspension for injection. The following instructions concerning reconstitution should be followed to minimise reconstitution issues:
The suspension for injection is intended for single use only. After drawing the suspension into the syringe for administration using the needle suitable for reconstitution, change this needle for a new needle suitable for intramuscular administration: a needle of a diameter of at least 700μm (needle gauge: 22G, 21G or 20G) for intramuscular injection is preferred. Because of the high concentration of suspended material, the needle may become blocked if intramuscular injection of the reconstituted product to the patient is not made at a slow, steady rate. If a blockage is observed during intramuscular administration, the blocked needle should be replaced with a new needle of the same diameter and administration of the remaining dose may then continue. Prior to injection, intravascular administration should be excluded by aspiration. The injection site should be changed with repeated injections.
Benzylpenicillin benzathine 1.2 Million I.U. powder for suspension for injection comes as oral solution. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.
The active substance in Benzylpenicillin benzathine 1.2 Million I.U. powder for suspension for injection is benzylpenicillin benzathine.
Medicines with the same active substance, strength and form include: Benzylpenicillin benzathine 2.4 Million I.U. powder for suspension for injection. They are interchangeable only if your prescriber or pharmacist says so.
This leaflet reproduces the patient information leaflet approved for Benzylpenicillin benzathine 1.2 Million I.U. powder for suspension for injection, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
Benzylpenicillin benzathine is indicated in adults, adolescents, children and neonates for the treatment and prophylaxis of the following infections (see section 5.1):
For the treatment of:
- erysipelas
- syphilis: early syphilis (primary and secondary)
- latent syphilis (except for neurosyphilis and presence of pathological CSF findings)
- yaws
- pinta
For the prophylaxis of:
- rheumatic fever (chorea, rheumatic carditis)
- poststreptococcal glomerulonephritis
- erysipelas
Consideration should be given to official guidance on the appropriate use of antibacterial agents.
Posology
The dosing recommendations depend on the severity and the type of infection, the age and the hepato-renal function of patients.
Dosage and duration of treatment
1. General therapy:
- Adults and adolescents:
- Children (> 30 kg body weight):
- Children (< 30 kg body weight):
Duration of treatment:
1.2 Million I.U.
1.2 Million I.U.
0.6 Million I.U.
Single dose
Note: In streptococcal diseases, a 10-day minimum course of treatment should be observed to avoid secondary diseases. This is generally ensured with a single injection of 0.6 Million I.U., 1.2 Million I.U. or 2.4 Million I.U..
2. Treatment of syphilis:
2.1. Primary and secondary stage
- Adults and adolescents:
- Children:
Duration of treatment:
2.4 Million I.U.
50,000 IU per kg body weight; however not more than 2.4 Million I.U.
Single dose (If clinical symptoms recur or laboratory findings remain strongly positive, treatment should be repeated.)
2.2. Late-stage syphilis (latent seropositive syphilis)
- Adults and adolescents:
- Children:
Duration of treatment:
2.4 Million I.U.
50,000 IU per kg body weight per week; however not more than 2.4 Million I.U.
Once weekly for 3 weeks
2.3. Treatment of congenital syphilis (without neurological involvement)
- Neonates and infants:
Duration of treatment:
50,000 IU per kg body weight
Single dose
3. Treatment of yaws and pinta:
- Adults and adolescents:
- Children (> 30 kg body weight):
- Children (< 30 kg body weight):
Duration of treatment:
1.2 Million I.U.
1.2 Million I.U.
0.6 Million I.U.
Single dose
4. Prophylaxis of rheumatic fever, poststreptococcal glomerulonephritis and erysipelas:
- Adults and adolescents:
- Children (> 30 kg body weight):
- Children (< 30 kg body weight):
1.2 Million I.U.
1.2 Million I.U.
0.6 Million I.U.
Duration of treatment:
a) without cardiac involvement:
b) transient cardiac involvement:
c) persistent cardiac involvement:
at least 5 years (or up to 21 years of age) every 3-4 weeks
at least 10 years (or up to 21 years of age) every 3-4 weeks
at least 10 years (or up to 40 years of age) every 3-4 weeks; life-long prophylaxis is sometimes necessary
Special patient groups
Patients with impaired renal function
Table 1 - Recommended dose adjustments in patients with impaired renal function.
Dosage for adults, adolescents and children based on creatine clearance
Creatinine clearance in ml/min
≥ 60
59 – 15
< 15
Proportion of the normal daily dose (%)
100
75
20 – 50
(1 – 3 Million I.U. per day maximum.)
Dosage interval
1 single administration
1 single administration
in 2 – 3 single administrations
Haemodialysis patients
Benzylpenicillin benzathine can be removed by haemodialysis. There are no data available on the influence of dialysis on the plasma levels of benzylpenicillin. The decision to treat patients on dialysis with Benzylpenicillin benzathine 1.2 Million I.U. and 2.4 Million I.U. powder for suspension for injection needs therefore to be taken on a case by case basis.
Patients with impaired hepatic function
In very severe cases of impaired hepatic and renal function, there may be a delay in the degradation and excretion of penicillin.
Method of administration
The preparation is strictly for intramuscular injection (see section 4.4).
The injection must not be administered into tissue with reduced perfusion (see section 4.4).
Benzylpenicillin benzathine 1.2 Million I.U. and 2.4 Million I.U. powder for suspension for injection should be administered by deep intramuscular injection into the upper, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field, with the needle pointing towards the iliac crest or according to von Hochstetter's method. The puncture should be as vertical to the skin surface as possible and the injection as far away from major vessels as possible. In all events, aspiration must be performed prior to the injection. If aspiration of blood or pain occurs during the injection, it must be discontinued.
In children, the mid-lateral thigh muscles (quadriceps femoris) are recommended as an injection site. The deltoid muscle is only suitable if it is well formed; in this case, attention must be paid to the radial nerve.
In infants and young children, the peripheral area of the upper outer quadrant of the gluteal region should be used as the area for injection only in exceptional cases (e.g. widespread burns), in order to avoid sciatic nerve lesions.
In general, a needle of a diameter of at least 700μm (needle gauge: 22, 21 or 20) for intramuscular injection is preferred.
For depot preparations, a total volume of 5ml per injection site is stated as the tolerance limit. Thus, no more than 5ml of the ready-to-inject suspension should be administered at any one time into one site. Benzylpenicillin benzathine 1.2 Million I.U. powder for suspension reconstituted with at least 3.5ml of diluent may therefore be injected into a single injection site where clinically appropriate and provided no more than 4ml of diluent is used in the case of 1.2 Million I.U. vials. In the case of Benzylpenicillin benzathine 2.4 Million I.U. powder for suspension for injection reconstituted with at least 5ml of diluent, the final reconstituted volume of approximately 7ml should be divided and administered across two injection sites.
The injection should be given as slowly as possible and only with the application of low pressure. “Rubbing” after the injection should be avoided.
Severe local reactions may occur during intramuscular administration, especially in young children. If possible, taking into account the therapeutic indications and schedule regimens and weighing the benefit-risk ratio, alternative treatments such as intravenous therapy with a suitable penicillin product should be considered (see also section 4.4).
For instructions on reconstitution of the medicinal product before administration, see section 6.6.
- Hypersensitivity to penicillins or any of the excipients listed in section 6.1.
- History of a severe immediate hypersensitivity reaction (e.g. anaphylaxis) to another beta-lactam agent (e.g. cephalosporin, carbapenem or monobactam).
- When lidocaine solution is used as a solvent, contraindications to lidocaine must be excluded before intramuscular injection of benzylpenicillin benzathine (see section 4.4 and section 6.6).
Benzylpenicillin benzathine should not be used in tissues with reduced perfusion.
Before initiating therapy with benzylpenicillin benzathine, a careful investigation should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins or other beta-lactam agents (see sections 4.3 and 4.8).
Serious and occasionally fatal hypersensitivity (analphylactoid) reactions have been reported in patients on penicillin therapy. These reactions are more likely to occur in individuals with a history of penicillin hypersensitivity and in atopic individuals. If an allergic reaction occurs, benzylpenicillin benzathine must be discontinued and appropriate therapy instituted.
Prior to treatment, a hypersensitivity test should be performed if possible. The patient should be made aware of the possible occurrence of allergic symptoms and of the need to report them.
Caution should be exercised in patients with the following conditions:
- allergic diathesis or bronchial asthma (there is an increased risk of a hypersensitivity reaction):
- renal insufficiency (for dose adjustment, see section 4.2);
- impaired hepatic function (see section 4.2).
Based on a general principle, particularly in some exposed patients, medical observation should if possible be ensured for at last half an hour after the administration of this antibiotic, as severe immediate allergic reactions may occur even after the first administration.
Beta-lactams are associated with a risk of encephalopathy (confusion, altered levels of consciousness, epilepsy or movement abnormalities), particularly in cases of over-dose or impaired renal function.
When treating syphilis, a Jarisch-Herxheimer reaction may occur as a result of the bactericidal action of penicillin on pathogens. Within 2 to 12 hours after administration headaches, fever, sweating, shivering, myalgia, arthralgia, nausea, tachycardia, increased blood pressure followed by hypotension may occur. These symptoms resolve after 10 to 12 hours. Patients should be informed that this is a usual, transient sequela of antibiotic therapy. Appropriate therapy should be instituted to suppress or attenuate a Jarisch-Herxheimer reaction (see section 4.8).
With long-term treatment (more than a single dose), periodic assessment of organ system functions, including renal, hepatic and haematopoietic function is recommended.
Prolonged use of benzylpenicillin benzathine may occasionally result in an overgrowth of non-susceptible organisms or yeast and patients should be observed carefully for superinfections.
Antibiotic-associated colitis has been reported with nearly all antibacterial agents including benzylpenicillin benzathine and may range in severity from mild to life threatening (see section 4.8). Therefore, it is important to consider this diagnosis in patients who present with diarrhoea during or subsequent to the administration of any antibiotics. Should antibiotic-associated colitis occur, benzylpenicillin benzathine should be discontinued, a physician be consulted, and an appropriate therapy initiated. Anti-peristaltic drugs are contraindicated in this situation.
If neurological involvement cannot be excluded in patients with congenital syphilis, forms of penicillin that reach a higher level in cerebrospinal fluid should be used.
In diseases such as severe pneumonia, empyema, sepsis, meningitis or peritonitis, which require higher serum penicillin levels, alternative treatment such as the water-soluble alkali salt of benzylpenicillin should be considered.
Notes on administering benzylpenicillin benzathine
Painful induration may occur in the event of accidental subcutaneous administration. Ice packs help in such cases.
In the event of inadvertent intravascular injection, Hoigné syndrome may occur (symptoms of shock with mortal fear, confusion, hallucinations, possibly cyanosis, tachycardia and motor disorders, although no circulatory collapse), caused by microemboli of the suspension. The symptoms regress within an hour. If progression is severe, parenteral administration of sedatives is indicated.
In the event of inadvertent intra-arterial injection, particularly in children, serious complications may occur, such as vascular occlusion, thrombosis and gangrene. Initial signs are pale patches in the skin area of the gluteal region. As a result of high injection pressure, retrograde entry of the injected liquid into the common iliac artery, aorta or spinal arteries may occur.
Repeated injections into a limited area of the muscle tissue, which are associated with long term therapy with depot-penicillins (e.g. in the treatment of syphilis) may induce tissue damage and increased local vascularization. Subsequent injections increase the possibility of penetration of injection substance into the blood, either by direct injection into a blood vessel or caused by the injection pressure itself, or by “rubbing” of the depot. During long term therapy it is therefore recommended to administer each injection a large distance from the preceding injection.
Effect on diagnostic laboratory procedures:
- A positive direct Coombs' test often develops (≥ 1% to < 10%) in patients receiving 10 million IU (equivalent to 6 g) benzylpenicillin or more per day. After discontinuation of the penicillin, the direct antiglobulin test may remain positive for 6 to 8 weeks (see section 4.8).
- Determination of urinary protein using precipitation techniques (sulphosalicylic acid, trichloroacetic acid), the Folin-Ciocalteu-Lowry method or the biuret method may lead to false positive results. Urinary protein should therefore be determined by other methods.
- Urinary amino acid determination using the ninhydrin method may likewise lead to false-positive results.
- Penicillins bind to albumin. In electrophoresis methods to determine albumin, pseudobisalbuminaemia may therefore be simulated.
- During therapy with benzylpenicillin benzathine, non-enzymatic urinary glucose detection and urobilinogen detection may exhibit a false positive.
- When determining 17-ketosteroids (using the Zimmermann reaction) in the urine, increased values may occur during therapy with benzylpenicillin benzathine.
Excipients
Benzylpenicillin benzathine 1.2 Million I.U. and 2.4 Million I.U. powder for suspension for injection contains phospholipids from the soya lecithin. If you are allergic to peanut or soya, do not use this medicinal product.
This medicine contains less than 1 mmol sodium (23 mg) per vial of 1.2 Million I.U. and 2.4 Million I.U., i.e. essentially 'sodium-free'.
Delayed excretion of povidone should be taken into consideration in patients with renal impairment. As this medicinal product contains povidone, it cannot be ruled out that frequent or prolonged use may very rarely lead to the accumulation of povidone in the reticuloendothelial system (RES), or to local deposits and the formation of foreign body granulomas which may be confused with tumours.
Use of lidocaine
When lidocaine solution is used as a solvent (see section 6.6), contraindications to lidocaine, warnings and other relevant information as detailed in the Summary of Product Characteristics of lidocaine must be considered before use (see section 4.3).
Concomitant administration of benzylpenicillin benzathine is not recommended with:
- bacteriostatic antibiotics: based on the general principle not to combine bactericidal and bacteriostatic antibiotics.
Caution should be exercised when co-administering the following:
- probenecid: the administration of probenecid leads to inhibition of the tubular secretion of benzylpenicillin, resulting in an increase in the serum concentration and prolongation of the elimination half-life. Furthermore, probenecid inhibits the penicillin transport from the cerebrospinal fluid, so that the concomitant administration of probenecid reduces the penetration of benzylpenicillin into brain tissue even further.
- methotrexate: when taken at the same time as benzylpenicillin benzathine, the excretion of methotrexate is reduced. This can lead to increased methotrexate toxicity. The combination with methotrexate is not recommended.
- anticoagulants: concomitant use with oral anticoagulants may increase the anti-vitamin K effect and the risk of bleeding. It is recommended that the International Normalised Ratio (INR) is monitored frequently and the posology of the anti-vitamin K drug adjusted accordingly, both during and after treatment with benzylpenicillin benzathine.
Pregnancy
Benzylpenicillin benzathine crosses the placenta. 10-30% of maternal plasma concentrations are found in the foetal circulation. High concentrations are also reached in the amniotic fluid. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. Benzylpenicillin benzathine can be used during pregnancy when appropriately indicated and with due consideration of the benefits and risks.
Breast-feeding
Benzylpenicillin benzathine is excreted in human milk in small amounts. The concentration in maternal milk may reach 2 to 15% of the mother's serum concentrations.
Although no undesirable effects in infants fed on breast milk have been reported to date, consideration must nevertheless be given to the possibility of sensitisation or interference with the intestinal flora. Breast-feeding should be stopped in the case of occurrence of diarrhoea, candidosis or rash in the child.
In infants also being fed on baby food, mothers should express and discard breast milk during benzylpenicillin benzathine treatment. Breast-feeding can be resumed 24 hours after finishing treatment.
Fertility
No fertility studies have been conducted in humans. Reproductive studies on mice, rats and rabbits have not revealed any negative effects on fertility. No long-term fertility studies on laboratory animals are available.
Due to the occurrence of possible serious undesirable effects (e.g. anaphylactic shock with collapse and anaphylactoid reactions, see also section 4.8), Benzylpenicillin benzathine can have a major influence on the ability to drive and use machines.
Summary of the safety profile
The most frequent and common adverse reactions related to benzylpenicillin benzathine are candidiasis, diarrhoea, nausea and laboratory investigation changes.
Table 2 - Tabulated list of adverse drug reactions by MedDRA System Organ Class.
MedDRA System Organ class
Common
(> 1/100 to < 1/10)
Uncommon
(> 1/1,000 to < 1/100)
Rare
(> 1/10,000 to < 1/1,000)
Very rare
(< 1/10,000)
Frequency not known (cannot be estimated from available data)
Infections and infestations
Candidiasis
Blood and lymphatic system disorders
Haemolytic anaemia
Leukopenia
Thrombocytopenia
Agranulocytosis
Immune system disorders
Allergic reactions
Urticaria
Angioedema
Erythema multiform
Exfoliative dermatitis
Fever
Arthralgia
Anaphylactic shock with collapse and anaphylactoid reactions (asthma, purpura, gastrointestinal symptoms)
Serum sickness
Gastrointestinal disorders
Diarrhoea
Nausea
Stomatitis and glossitis
Vomiting
Pseudomembranous colitis (see section 4.4)
Hepatobiliary disorders
Hepatitis
Cholestasis
Renal and urinary disorders
Nephropathy
Interstitial nephritis
General disorders and administration site conditions
Pain at the injection site
Injection site infiltrates
Hoigné syndrome
Nicolau syndrome
Investigations
Positive direct Coombs' test
False-positive urinary protein determination when precipitation techniques are used (Folin-Ciocalteu-Lowry method, biuret method)
False-positive urinary amino acid determination (ninhydrin method)
Simulation of pseudobisalbuminaemia when using electrophoresis methods to determine albumin
False-positive non-enzymatic urinary glucose detection and urobilinogen detection
Increased levels when determining 17-ketosteroids in urine (when the Zimmermann reaction is used) (see section 4.4)
Description of selected adverse reactions
When treating syphilis, a Jarisch-Herxheimer reaction may occur as a result of bacteriolysis, characterised by fever, chills, general and focal symptoms. In patients with dermatomycosis, para-allergic reactions may occur, as common antigenicity may exist between penicillins and dermatophyte metabolites.
In infants, local reactions are possible.
It cannot be excluded that, in very rare cases and due to the povidone content, povidone may accumulate in the reticuloendothelial system (RES) or local deposits and foreign body granuloma may occur, which may be confused with tumours.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme (website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store).
At extremely high doses, penicillins can induce neuromuscular excitability or epileptiform seizures. If overdose is suspected, clinical monitoring and symptomatic measures are indicated. Benzylpenicillin can be haemodialyzed.
Ask anything about Benzylpenicillin benzathine 1.2 Million I.U. powder for suspension for injection. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.
We use essential cookies to make the site work. We would also like to set optional cookies to understand how the site is used, so we can improve it. We will not set optional cookies unless you accept. See our cookie policy and privacy policy.