Phenoxymethylpenicillin


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Susceptible infections 250-500 mg 6 hrly. Prophylaxis of recurrent rheumatic fever 250 mg bid. Streptococcal infections of the upper resp tract, including scarlet fever and erysipelas 125-250 mg 6-8 hrly for 10 days. Pneumococcal infections of the resp tract, including otitis media 250-500 mg 6 hrly until the patient is afebrile for at least 2 days. Fusospirochetosis (Vincent's infection) of the oropharynx; Staphylococcal infections of the skin and soft tissue 250-500 mg 6-8 hrly.
Dosage Details
Oral
Erysipelas, Scarlet fever, Streptococcal infections of the upper respiratory tract
Adult: 125-250 mg 6-8 hrly for 10 days.

Oral
Fusospirochetosis (Vincent's infection) of the oropharynx, Staphylococcal infections of the skin and soft tissue
Adult: 250-500 mg 6-8 hrly.

Oral
Pneumococcal infections of the respiratory tract, including otitis media
Adult: 250-500 mg 6 hrly until the patient is afebrile for at least 2 days.
Child: <1 yr 62.5 mg 6 hrly; 1-5 yr 125 mg 6 hrly; 6-12 yr 250 mg 6 hrly.

Oral
Prophylaxis of recurrent rheumatic fever
Adult: 250 mg bid.
Child: <1 yr 62.5 mg 6 hrly; 1-5 yr 125 mg 6 hrly; 6-12 yr 250 mg 6 hrly.

Oral
Susceptible infections
Adult: 250-500 mg 6 hrly.
Child: <1 yr 62.5 mg 6 hrly; 1-5 yr 125 mg 6 hrly; 6-12 yr 250 mg 6 hrly.
Renal Impairment
Dose adjustment may be necessary.
Administration
Should be taken on an empty stomach. Take 1 hr before or 2 hr after meals.
Reconstitution
Powd for oral soln: Add the amount of water specified on the bottle to provide a soln containing 125 mg or 250 mg per 5 mL. The water should be added to the powd in 2 portions and the soln agitated vigorously immediately after each addition.
Contraindications
Hypersensitivity to to phenoxymethylpenicillin and other penicillins. Concomitant use w/ nadolol and propranolol.
Special Precautions
Patient w/ history of asthma, seizure disorders, history of β-lactam allergy. Severe renal impairment. Pregnancy and lactation.
Adverse Reactions
Nausea, vomiting, abdominal pain, diarrhoea, sore mouth, black hairy tongue, thrombocytopenia, neutropenia, leucopenia, eosinophilia, haemolytic anaemia, coagulation disorders, hepatitis, cholestatic jaundice, allergic reactions, serum sickness-like reactions, convulsions, paraesthesia, neuropathy, interstitial nephritis, nephropathy, urticaria, rash, pruritus.
Potentially Fatal: Anaphylaxis, pseudomembranous colitis.
MonitoringParameters
Monitor renal and haematologic functions, signs of anaphylaxis during 1st dose.
Overdosage
Symptoms: Nausea, vomiting, stomach pain, diarrhoea, and rarely, major motor seizures. If other symptoms are present, consider the possibility of an allergic reaction. Hyperkalaemia may result, particularly for patients w/ renal insufficiency. Management: Symptomatic and supportive treatment. May admin activated charcoal w/ a cathartic, e.g. sorbitol to hasten drug elimination. May be removed by haemodialysis.
Drug Interactions
Reduced absorption w/ neomycin. May interfere w/ anticoagulant control. Antagonism of bactericidal effect by chloramphenicol, erythromycin and tetracyclines. May increase toxicity of methotrexate. May reduce the efficacy of OC. Reduced excretion w/ probenecid and sulfinpyrazone. May inactivate oral typhoid vaccine if ingested concomitantly.
Potentially Fatal: Increased risk of anaphylactic reactions w/ nadolol and propranolol.
Food Interaction
Absorption may be slightly affected by food.
Lab Interference
False-positive urine glucose reactions w/ Clinitest, Benedict soln, or Fehling soln. Positive Coombs test.
Action
Description: Phenoxymethylpenicillin inhibits the final cross-linking stage of peptidoglycan production through binding and inactivation of transpeptidases on the inner surface of the bacterial cell membrane, thus inhibiting bacterial cell wall synthesis. It may be less active against some susceptible organisms, particularly gm-ve bacteria. It is suitable for mild to moderate infections.
Pharmacokinetics:
Absorption: Rapidly but incompletely absorbed (approx 60%) from the GI tract. Absorption is slightly affected by the presence of food. Bioavailability: Approx 60%. Time to peak plasma concentrations: 30-60 min.
Distribution: Widely distributed into body tissues. Crosses the placenta and enters breast milk. Plasma protein binding: Approx 80%.
Metabolism: Undergoes hepatic metabolism. Several metabolites have been identified, including penicilloic acid.
Excretion: Via urine (as unchanged drug and metabolites) and bile (small amounts). Plasma half-life: Approx 30-60 min.
Chemical Structure

Chemical Structure Image
Phenoxymethylpenicillin

Source: National Center for Biotechnology Information. PubChem Database. Penicillin v, CID=6869, https://pubchem.ncbi.nlm.nih.gov/compound/Penicillin-v (accessed on Jan. 22, 2020)

Storage
Tab/powd for oral soln: Store between 20-25°C. Reconstituted oral soln: Store between 2-8°C. Protect from light.
MIMS Class
References
Anon. Penicillin V Potassium (Oral). Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 25/06/2014.

Buckingham R (ed). Phenoxymethylpenicillin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 25/06/2014.

McEvoy GK, Snow EK, Miller J et al (eds). Penicillin V, Penicillin V Potassium. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 25/06/2014.

Penicillin V Potassium Tablet (Sandoz Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 25/06/2014.

Wickersham RM. Penicillin V Potassium. Facts and Comparisons [online]. St. Louis, MO. Wolters Kluwer Clinical Drug Information, Inc. https://www.wolterskluwercdi.com/facts-comparisons-online/. Accessed 25/06/2014.

Disclaimer: This information is independently developed by MIMS based on Phenoxymethylpenicillin from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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