Erythromycin Base 500mg Tablets

Erythromycin inhibits bacterial protein synthesis by reversibly binding to the 50S ribosomal subunit of susceptible microorganisms. This binding blocks the translocation reaction, preventing the addition of new amino acids to the growing peptide chain, thereby inhibiting protein synthesis.

Urgent Side Effects: Seek Medical Help Immediately

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention right away:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Signs of a severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), such as:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Difficulty urinating or changes in urine output
Severe dizziness or fainting
Rapid heartbeat
Abnormal heartbeat (long QT on ECG), which can be life-threatening. This risk may be increased when taking other medications with this drug. Seek medical help immediately if you experience an irregular heartbeat.
Diarrhea, particularly if it is severe, bloody, or watery. Although diarrhea is common with antibiotics, a rare but potentially deadly condition called C. diff-associated diarrhea (CDAD) may occur. Contact your doctor right away if you experience stomach pain, cramps, or severe diarrhea. Do not treat diarrhea without consulting your doctor.
Hearing loss, which may be temporary but can be more likely to occur if you have kidney problems or take high doses of this medication. If you experience hearing problems, such as hearing loss, contact your doctor immediately.

Other Possible Side Effects

Most people do not experience severe side effects, and many have none or only mild symptoms. However, if you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical attention:

Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite

This is not an exhaustive list of possible side effects. If you have concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Describe the allergic reaction you experienced, including the symptoms that occurred.
Certain health conditions, including:
+ Abnormal heartbeat patterns, such as a prolonged QTc interval on an electrocardiogram (ECG)
+ Other irregular heartbeats
+ Slow heartbeat
+ Low potassium or magnesium levels

Additionally, disclose all medications you are currently taking, including:

Prescription and over-the-counter (OTC) drugs
Natural products
* Vitamins

This is crucial because some medications, particularly those used to treat mood disorders, irregular heartbeats, or migraine headaches, should not be taken with this drug. There are numerous medications that interact with this drug, and this list is not exhaustive.

To ensure your safety, inform your doctor and pharmacist about all your medications and health conditions. Verify that it is safe to take this medication with your existing medications and health conditions. Never start, stop, or adjust the dosage of any medication without consulting your doctor.

Important Information for Patients Taking This Medication

It is crucial that you inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

If you are taking this medication long-term, your doctor may recommend regular blood tests to monitor your condition. Be sure to discuss this with your doctor.

This medication may interfere with certain laboratory tests. Therefore, it is essential to notify all your healthcare providers and laboratory personnel that you are taking this medication.

Do not take this medication for a longer period than prescribed by your doctor. Prolonged use may increase the risk of a second infection.

If you are following a low-sodium or sodium-free diet, consult your doctor before taking this medication, as some products may contain sodium.

If you have myasthenia gravis, discuss your condition with your doctor. Monitor your symptoms closely, and contact your doctor if they worsen. Additionally, be aware that myasthenia gravis symptoms, such as new or worsening muscle weakness, difficulty chewing or swallowing, breathing problems, droopy eyelids, or changes in vision (including blurred vision or double vision), can occur in people without a history of the condition. If you experience any of these symptoms, contact your doctor immediately.

If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.

If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor to discuss the potential benefits and risks to you and your baby.

Special Considerations for Newborns

In newborns taking this medication, a severe stomach problem can occur. If your child vomits or becomes irritable during feeding, contact your doctor right away.

• Colchicine (in patients with renal or hepatic impairment)
• Ergotamine, Dihydroergotamine (risk of acute ergot toxicity)
• HMG-CoA reductase inhibitors (statins) metabolized by CYP3A4 (e.g., simvastatin, lovastatin) - risk of rhabdomyolysis
• Pimozide (risk of QT prolongation and cardiac arrhythmias)
• Lurasidone (risk of increased lurasidone exposure)
• Eliglustat (in patients who are CYP2D6 poor metabolizers or taking strong/moderate CYP2D6 inhibitors)

• Amiodarone, Disopyramide, Dofetilide, Dronedarone, Ibutilide, Quinidine, Sotalol (increased risk of QT prolongation and Torsades de Pointes)
• Fluoroquinolones (e.g., moxifloxacin, levofloxacin) - additive QT prolongation risk
• Anticoagulants (e.g., warfarin) - increased INR and bleeding risk
• Carbamazepine, Phenytoin, Valproic acid - increased anticonvulsant levels and toxicity
• Theophylline - increased theophylline levels and toxicity
• Cyclosporine, Tacrolimus, Sirolimus - increased immunosuppressant levels and nephrotoxicity
• Cisapride (risk of QT prolongation and cardiac arrhythmias - generally contraindicated in many regions)
• Oral contraceptives (potential for reduced efficacy, though evidence is mixed)
• Digoxin - increased digoxin levels
• Sildenafil, Tadalafil, Vardenafil - increased PDE5 inhibitor exposure
• Alprazolam, Midazolam, Triazolam - increased benzodiazepine levels and sedation
• Quetiapine - increased quetiapine exposure
• Rifampin, Phenobarbital, Phenytoin (CYP3A4 inducers) - decreased erythromycin levels
• Clindamycin, Lincomycin (antagonistic effect due to similar binding site)

• Calcium channel blockers (e.g., verapamil, diltiazem, amlodipine) - increased CCB levels
• Corticosteroids (e.g., methylprednisolone) - increased corticosteroid levels
• Cimetidine, Ranitidine (H2 blockers) - may affect erythromycin absorption (less significant for enteric-coated)
• Grapefruit juice - may inhibit CYP3A4, increasing erythromycin levels (less significant for base)

• Antacids (containing aluminum or magnesium) - may reduce absorption if taken concurrently (separate by 2 hours)

• Nausea
• Vomiting
• Abdominal pain
• Diarrhea
• Jaundice
• Dark urine
• Fatigue (signs of hepatotoxicity)
• Palpitations
• Dizziness
• Syncope (signs of QT prolongation/arrhythmia)
• Tinnitus
• Hearing loss (signs of ototoxicity)
• Muscle pain/weakness (if co-administered with statins)

Erythromycin is generally considered safe for use during pregnancy when indicated. It was previously classified as Pregnancy Category B. Current guidelines suggest it is a preferred macrolide for certain infections in pregnancy.

Erythromycin is excreted into breast milk in small amounts. It is generally considered compatible with breastfeeding (Lactation Risk Category L2). Monitor breastfed infant for gastrointestinal disturbances (e.g., diarrhea, candidiasis) or rash.

Erythromycin base tablets are generally not recommended for neonates due to formulation and potential for infantile hypertrophic pyloric stenosis (IHPS) with erythromycin ethylsuccinate. Dosing for infants and children is weight-based. Close monitoring for IHPS is crucial in infants, especially those under 1 month of age, if any erythromycin formulation is used.

No specific dose adjustment is required based on age alone. However, elderly patients may be more susceptible to QT prolongation, hearing loss, and drug interactions due to polypharmacy, renal/hepatic impairment, and underlying cardiac conditions. Monitor closely for adverse effects and drug interactions.

• Erythromycin is a potent CYP3A4 inhibitor; careful review of concomitant medications is crucial to avoid serious drug interactions (e.g., statins, warfarin, antiarrhythmics).
• GI upset (nausea, vomiting, abdominal cramps, diarrhea) is a very common side effect, often dose-related. Taking with food may help, but for enteric-coated base, food effect is minimal.
• Risk of QT prolongation and Torsades de Pointes, especially with pre-existing cardiac conditions, electrolyte imbalances, or concomitant QT-prolonging drugs.
• Rare but serious side effects include hepatotoxicity (cholestatic hepatitis) and ototoxicity (reversible hearing loss, tinnitus), particularly with high doses or in patients with renal/hepatic impairment.
• Erythromycin is effective against atypical pathogens (e.g., Mycoplasma, Chlamydia, Legionella) and many Gram-positive bacteria.
• Resistance to macrolides is increasing, limiting its empirical use in some areas.
• Infantile hypertrophic pyloric stenosis (IHPS) is a rare but serious risk in neonates, particularly with erythromycin ethylsuccinate. Use in neonates should be carefully considered.

• Azithromycin (another macrolide, longer half-life, less frequent dosing, fewer CYP interactions)
• Clarithromycin (another macrolide, similar spectrum, CYP3A4 inhibitor)
• Doxycycline (tetracycline, broad spectrum, alternative for atypical pathogens)
• Amoxicillin/Clavulanate (beta-lactam/beta-lactamase inhibitor, for susceptible bacterial infections)
• Levofloxacin/Moxifloxacin (fluoroquinolones, broad spectrum, but with QT prolongation risk)

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.