(erythromycin · DailyMed)
ERYCONOR WATER SOLUBLE POWDER
Colistin/ Erythromycin thiocyanate
What it does
Colistin is an antibiotic used to treat serious infections caused by certain bacteria, especially when other antibiotics are not effective.
Commonly used for: serious bacterial infections, pneumonia, blood infections (sepsis)
Read more in plain English ↓Plain-language summary for general understanding - not medical advice. Always follow your pharmacist/doctor.
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Sourcing - Kenya onlyRegistration & product details
Source: Food and Drugs Authority · fetched 2026-04-18 08:33:06 · updated 2026-10-20 04:00:10
Drug Interactions
151Pharmacodynamic Warnings
Erythromycin appears in TABLE 9: Drugs that prolong the QT interval
Severe (14)
Antipsychotics, Second Generation - increases exposure
Erythromycin is predicted to increase the exposure to antipsychotics, second generation (cariprazine). Avoid.
Cariprazine - increases exposure
Erythromycin is predicted to increase the exposure to antipsychotics, second generation (cariprazine). Avoid.
Eletriptan - increases exposure
Erythromycin moderately increases the exposure to triptans (eletriptan). Avoid.
Ergometrine - increases risk of ergotism
Macrolides (clarithromycin) are predicted to increase the risk of ergotism when given with ergometrine. Avoid.
Ergotamine - increases risk of ergotism
Macrolides (clarithromycin) are predicted to increase the risk of ergotism when given with ergotamine. Avoid.
Moderate (38)
Alfentanil - increases exposure
Erythromycinispredictedtoincreasetheexposuretoopioids (alfentanil,buprenorphine,fentanyl,oxycodone).Monitorand adjustdose.oStudy com/codemedicalapps/ cal Applications)
Amlodipine - increases exposure
Erythromycin is predicted to increase the exposure to calcium channel blockers (amlodipine, felodipine, lacidipine, lercanidipine, nicardipine, nifedipine, nimodipine). Monitor and adjust dose.
Antiarrhythmics - increases exposure
Erythromycin is predicted to increase the exposure to antiarrhythmics (propafenone). Monitor and adjust dose.
Antiepileptics - increases concentration
Erythromycin markedly increases the concentration of antiepileptics (carbamazepine). Monitor concentration and adjust dose.
Atorvastatin - increases exposure
Erythromycins slightly increases the exposure to statins (atorvastatin). Monitor and adjust dose.
Unknown (99)
Abemaciclib - increases exposure
Erythromycin is predicted to increase the exposure to abemaciclib.
Acalabrutinib - increases exposure
Erythromycin is predicted to increase the exposure to acalabrutinib. Avoid or monitor.
Afatinib - increases exposure
Macrolides are predicted to increase the exposure to afatinib.
Alphablockers - increases exposure
Erythromycin is predicted to increase the exposure to alpha blockers (tamsulosin).
Alprazolam - increases exposure
Erythromycin is predicted to increase the exposure to benzodiazepines (alprazolam).
Data from BNF 85 (British National Formulary). This is not a substitute for professional medical advice. Matched via: exact
About colistin
Colistin is an antibiotic used to treat serious infections caused by certain bacteria, especially when other antibiotics are not effective.
What it treats
- serious bacterial infections
- pneumonia
- blood infections (sepsis)
How it works
Colistin works by attacking the outer membrane of bacteria, leading to their death and helping to clear the infection.
Who it's for
This medicine is for adults and children with severe infections caused by bacteria that are resistant to other treatments.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About erythromycin
Erythromycin is an antibiotic used to treat various bacterial infections.
What it treats
- bacterial infections
- bronchitis
- pneumonia
- skin infections
- ear infections
How it works
It works by stopping the growth of bacteria, helping the body to fight off infections.
Who it's for
It is suitable for adults and children who have certain bacterial infections.
Drug class
Macrolides
Cautions
- • Be careful if you are taking other medications that can affect heart rhythm.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About thiocyanate
Thiocyanate is a compound that can affect the body in various ways, often related to its role in certain medical conditions.
What it treats
- used in some medical tests
- helps assess thyroid function
How it works
Thiocyanate can influence how the body uses iodine, which is important for making thyroid hormones.
Who it's for
Thiocyanate may be used for individuals undergoing tests for thyroid-related issues.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
Clinical monograph: Erythromycin
BNF-referencedErythromycin is a macrolide antibiotic effective against a range of bacterial infections. It works primarily by inhibiting protein synthesis in susceptible bacteria, making it a valuable choice for patients with penicillin hypersensitivity. Erythromycin is commonly used in treating respiratory tract infections, skin infections, and various other bacterial infections, including those caused by organisms like Propionibacterium acnes.
Indications
- Bacterial infections
- Acute otitis media
- Community-acquired pneumonia
- Skin and soft tissue infections
- Campylobacter enteritis
- Pertussis
- Syphilis (early stage)
- Chlamydia infections
- Impetigo
- Secondary bacterial infection of eczema
Dosage
Children: Child 1–23 months: 125 mg 4 times a day. Child 2–7 years: 250 mg 4 times a
Adults: 500 mg 4 times a day for 5 days, or alternatively 250–500 mg 4 times a day for 5–7 days.
Mechanism of action
Erythromycin exerts its antibacterial effect by binding to the 23S ribosomal RNA in the 50S subunit of bacterial ribosomes. This binding inhibits the transpeptidation and translocation steps of protein synthesis, effectively halting bacterial growth. The drug has a strong affinity for bacterial ribosomes, which contributes to its broad-spectrum activity against various pathogens.
Pharmacodynamics
Erythromycin acts as a bacteriostatic agent, preventing bacterial growth by inhibiting protein synthesis. It is effective against many strains of bacteria, although susceptibility testing is recommended due to increasing resistance. Notably, erythromycin does not impact nucleic acid synthesis and may lead to complications such as pseudomembranous colitis or hepatotoxicity in some patients.
Pharmacokinetics
Erythromycin is well-absorbed from the gastrointestinal tract, with bioavailability affected by food. It is widely distributed in body tissues, with higher concentrations in the lungs and liver. The drug undergoes hepatic metabolism and is primarily excreted in bile, with a small amount eliminated through urine. Erythromycin's half-life varies but generally ranges from 1.5 to 2 hours.
Contra-indications
- Hypersensitivity to erythromycin or any component of the formulation
- History of cholestatic jaundice or hepatic dysfunction associated with prior use of erythromycin
Adverse effects
- Gastrointestinal disturbances (nausea, vomiting, diarrhea)
- Cholestatic jaundice
- Hepatotoxicity
- Skin rashes
- QT interval prolongation
- Tinnitus
- Hearing loss (reversible)
- Pseudomembranous colitis
Interactions
- Erythromycin may significantly increase the exposure to certain drugs such as antipsychotics, simvastatin, and triptans due to its effect on cytochrome P450 enzymes
- Caution with concurrent use of drugs that prolong the QT interval
- Moderate interaction with aminophylline (decreases exposure)
Precautions
- Use with caution in patients with hepatic impairment or pre-existing liver disease
- Monitor for signs of pseudomembranous colitis in patients with diarrhea following antibiotic use
- Assess for potential drug interactions due to the impact on CYP450 metabolism
Pregnancy
Erythromycin crosses the placenta. It is generally considered safe for use during pregnancy, particularly for treating infections when no alternatives are available, but should be used with caution.
Breast-feeding
Erythromycin is excreted in breast milk. While generally considered safe, the infant should be monitored for potential side effects. Consult healthcare providers for specific recommendations.
Storage
Store in a cool, dry place away from direct sunlight. Keep out of reach of children. Check specific product information for any temperature requirements.
Formulations
- Oral suspension (125 mg/5 ml)
- Tablets (250 mg and 500 mg)
- Injectable solution (various strengths for intravenous administration)
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: colistin
BNF-referencedColistin is a polymyxin antibiotic primarily used to treat infections caused by multidrug-resistant gram-negative bacteria. It acts as a surface-active agent that disrupts bacterial cell membranes, leading to cell death. Due to the emergence of antibiotic-resistant pathogens, colistin has regained importance in clinical settings, particularly for treating severe infections in patients with limited treatment options.
Indications
- Treatment of multidrug-resistant gram-negative bacterial infections
- Pneumonia caused by Pseudomonas aeruginosa
- Complicated urinary tract infections
- Infections in cystic fibrosis patients
Dosage
Children: Refer to the BNF for Children for appropriate paediatric dosing information.
Adults: Refer to the BNF for specific dosing guidelines, as doses may vary based on infection severity and renal function.
Mechanism of action
Colistin interacts with the bacterial cytoplasmic membrane, disrupting its integrity and altering permeability. It binds to the membrane through its cationic properties, leading to leakage of essential intracellular components, which results in bactericidal effects.
Pharmacodynamics
Colistin functions as a cationic polypeptide that disrupts bacterial cell membranes via a detergent-like mechanism. It is effective against certain multidrug-resistant organisms, including Pseudomonas aeruginosa and Acinetobacter baumannii. Its use has increased due to the rise of antibiotic-resistant infections, particularly in patients with cystic fibrosis and other serious infections.
Pharmacokinetics
Colistin is administered parenterally and has variable pharmacokinetics depending on the route of administration. It is not well-absorbed orally and is primarily eliminated by the kidneys. The pharmacokinetic profile may vary based on renal function and dosage regimen, necessitating careful monitoring in patients with renal impairment.
Adverse effects
- Nephrotoxicity
- Neurotoxicity
- Allergic reactions
- Rash
- Fever
Interactions
- Increased risk of nephrotoxicity with other nephrotoxic agents
- Potential interactions with neuromuscular blockers
Precautions
- Monitor renal function during treatment
- Use with caution in patients with renal impairment
- Consider monitoring neuromuscular function in patients receiving concomitant neuromuscular blockers
Pregnancy
Colistin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Breast-feeding
It is not known whether colistin is excreted in human milk. Caution should be exercised when administering to a nursing mother.
Storage
Store in a cool, dry place, away from light. Keep out of reach of children.
Formulations
- Colistin sulfate for injection
- Colistin methanesulfonate for injection
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: thiocyanate
BNF-referencedThiocyanate is an anion derived from thiocyanic acid, commonly found in various biological systems. It plays a role in sulfur metabolism and is involved in various biochemical pathways. Thiocyanate can be produced in the body through the metabolism of cyanide and is excreted primarily via the kidneys. Its presence in the body may reflect exposure to cyanogenic compounds or certain dietary sources, such as cruciferous vegetables.
Mechanism of action
Thiocyanate acts primarily by competing with iodide for uptake in the thyroid gland, thereby potentially inhibiting thyroid hormone synthesis. This can lead to a reduction in the production of thyroid hormones, affecting metabolic processes that are regulated by these hormones. Additionally, thiocyanate is involved in various metabolic pathways related to sulfur compounds, influencing overall redox status and metabolic homeostasis.
Pharmacodynamics
Thiocyanate has a notable effect on thyroid function due to its ability to inhibit iodide transport. This inhibition can result in decreased levels of thyroid hormones, which are crucial for regulating metabolism, growth, and development. The compound may also influence various metabolic pathways involving sulfur, interacting with enzymes and substrates related to sulfur metabolism.
Pharmacokinetics
Thiocyanate is absorbed through the gastrointestinal tract, and its distribution is influenced by factors such as protein binding and tissue uptake. The compound is primarily excreted through the kidneys, with renal clearance being a significant route of elimination. The half-life of thiocyanate can vary, but it is generally considered to be several days in the body, depending on individual metabolic rates and kidney function.
Pregnancy
Thiocyanate should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Breast-feeding
Thiocyanate is excreted in breast milk. Caution should be exercised when administering to nursing mothers.
Storage
Store in a tightly closed container at room temperature, away from heat and moisture.
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Molecular reference: Erythromycin
PubChem CID 12560Molecular formula: C37H67NO13
Mechanism of action
In order to replicate, bacteria require a specific process of protein synthesis, enabled by ribosomal proteins. Erythromycin acts by inhibition of protein synthesis by binding to the 23S ribosomal RNA molecule in the 50S subunit of ribosomes in susceptible bacterial organisms. It stops bacterial protein synthesis by inhibiting the transpeptidation/translocation step of protein synthesis and by inhibiting the assembly of the 50S ribosomal subunit. This results in the control of various bacterial infections. The strong affinity of macrolides, including erythromycin, for bacterial ribosomes, supports their broad‐spectrum antibacterial activities. Macrolide antibiotics are bacteriostatic agents that inhibit protein synthesis by binding reversibly to 50S ribosomal subunits of sensitive microorganisms, at or very near the site that binds chloramphenicol. Erythromycin does not inhibit peptide bond formation per se, but rather inhibits the translocation step wherein a newly synthesized peptidyl tRNA molecule moves from the acceptor site on the ribosome to the peptidyl donor site. Gram-positive bacteria accumulate about 100 times more erythromycin than do gram-negative bacteria. Cells are considerably more permeable to the un-ionized form of the drug, which probably explains the increased antimicrobial activity at alkaline pH. ... /Erythromycin/ inhibits the growth of susceptible organisms (principally Propionibacterium acnes) on the surface of the skin and reduces the concn of free fatty acids in sebum ... The reduction in free fatty acids in sebum may be an indirect result of the inhibition of lipase-producing organisms which convert triglycerides into free fatty acids or may be a direct result of interference with lipase production in these organisms. /In acne treatment regimens/ Although stromal-derived factor-1 (SDF-1) via its cognate receptor CXCR4 is assumed to play a critical role in migration of endothelial cells during new vessel formation after tissue injury, CXCR4 expression on endothelial cells is strictly regulated. Erythromycin (EM), a 14-membered ring macrolide, has an anti-inflammatory effect that may account for its clinical benefit in the treatment of chronic inflammatory diseases. However, the effects of EM on endothelial cells and especially their expression of CXCR4 have not been fully evaluated. In this study, we demonstrated that EM markedly induced CXCR4 surface expression on microvascular endothelial cells in vitro and lung capillary endothelial cells in vivo. This ability to induce CXCR4 surface expression on endothelial cells was restricted to 14-membered ring macrolides and was not observed in other antibiotics including a 16-membered ring macrolide, josamycin. Furthermore, this EM-induced expression of CXCR4 on endothelial cells was functionally significant as demonstrated by chemotaxis assays in vitro. These findings suggest that EM-induced CXCR4 surface expression on endothelial cells may promote migration of CXCR4-expressing endothelial cells into sites of tissue injury, which may be associated with the known anti-inflammatory activity of this macrolide.
Pharmacodynamics
Macrolides, such as erythromycin, stop bacterial growth by inhibiting protein synthesis and translation, treating bacterial infections. Erythromycin does not exert effects on nucleic acid synthesis. This drug has been shown to be active against most strains of the following microorganisms, effectively treating both in vitro and clinical infections. Despite this, it is important to perform bacterial susceptibility testing before administering this antibiotic, as resistance is a common issue that may affect treatment. **A note on antimicrobial resistance, pseudomembranous colitis, and hepatotoxicity** Many strains of Haemophilus influenzae are resistant to erythromycin alone but are found to be susceptible to erythromycin and sulfonamides used in combination. It is important to note that Staphylococci that are resistant to erythromycin may emerge during erythromycin and/or sulfonamide therapy. Pseudomembranous colitis has been reported with most antibacterial agents, including erythromycin, and may range in severity from mild to life-threatening. Therefore, the physician should consider this diagnosis in patients with diarrhea after the administration of antibacterial agents. Erythromycin can cause hepatic dysfunction, cholestatic jaundice, and abnormal liver transaminases, particularly when erythromycin estolate is administered.
Biological pathways
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.
Molecular reference: colistin
PubChem CID 5311054Molecular formula: C52H98N16O13
Mechanism of action
Colistin is a surface active agent which penetrates into and disrupts the bacterial cell membrane. Colistin is polycationic and has both hydrophobic and lipophilic moieties. It interacts with the bacterial cytoplasmic membrane, changing its permeability. This effect is bactericidal. There is also evidence that polymyxins enter the cell and precipitate cytoplasmic components, primarily ribosomes. POLYMYXIN B IS SURFACE-ACTIVE AGENT... CONTAINING LIPOPHILIC & LIPOPHOBIC GROUPS SEPARATED WITHIN MOLECULE. /POLYMYXIN B/ PERMEABILITY OF THE BACTERIAL MEMBRANE CHANGES IMMEDIATELY ON CONTACT WITH DRUG. SENSITIVITY TO POLYMYXIN B APPARENTLY IS RELATED TO THE PHOSPHOLIPID CONTENT OF THE CELL WALL-MEMBRANE COMPLEX. /POLYMYXIN B/ Colistin acts like a cationic detergent and binds to and damages the bacterial cytoplasmic membrane of susceptible bacteria. Damage to the bacterial cytoplasmic membrane alters the osmotic barrier of the membrane and causes leakage of essential intracellular metabolites and nucleosides.
Pharmacodynamics
Colistin is a polymyxin antibiotic agent. Polymyxins are cationic polypeptides that disrupt the bacterial cell membrane through a detergentlike mechanism. With the development of less toxic agents, such as extended-spectrum penicillins and cephalosporins, parenteral polymyxin use was largely abandoned, except for the treatment of multidrug-resistant pulmonary infections in patients with cystic fibrosis. More recently, however, the emergence of multidrug-resistant gram-negative bacteria, such as <i>Pseudomonas aeruginosa</i> and <i>Acinetobacter baumannii</i>, and the lack of new antimicrobial agents have led to the revived use of the polymyxins.
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.
Molecular reference: thiocyanate
PubChem CID 9322Molecular formula: CNS-
Biological pathways
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.
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