The pill with the imprint E 318 is Methadone Hydrochloride 10 mg, manufactured by Epic Pharma LLC (formerly West-Ward Pharmaceuticals).
Methadone is a synthetic, long-acting opioid agonist. It is classified as a Schedule II controlled substance in the United States, meaning it has a high potential for abuse and severe psychological or physical dependence, but also has accepted medical uses. It is primarily prescribed for the management of severe chronic pain or as part of a comprehensive treatment program for opioid use disorder (OUD).
Pill Identification
If you are examining a pill to verify its identity, it should match the following physical attributes:
- Imprint: E 318
- Color: White
- Shape: Round
- Active Ingredient: Methadone Hydrochloride 10 mg
- Manufacturer: Epic Pharma LLC
Mechanism of Action
Methadone works by altering the way the brain and nervous system respond to pain and opioid withdrawal:
- Mu-Opioid Receptor Agonism: Methadone binds strongly to the opioid receptors in the central nervous system (CNS). By mimicking natural endorphins, it blocks pain signals sent to the brain.
- Cross-Tolerance & Craving Suppression: In opioid maintenance therapy, methadone occupies the brain’s opioid receptors very slowly without producing the rapid “rush” or euphoria associated with shorter-acting opioids like heroin or oxycodone. Because those receptors are occupied, it prevents withdrawal symptoms and satisfies cravings. Furthermore, if a person attempts to use another opioid while on an adequate dose of methadone, the methadone blocks the euphoric effects of that secondary drug.
- NMDA Receptor Antagonism: Methadone also acts as an antagonist at the N-methyl-D-aspartate (NMDA) receptor. This secondary action helps modulate pain transmission and is believed to slow down the development of opioid tolerance.
Dosage and Administration
Methadone dosages must be highly individualized due to its unpredictable accumulation in body tissues and long half-life
For Opioid Use Disorder (Maintenance Therapy)
- Initial Dose: Usually ranges from 10 mg to 30 mg orally on day one, under strict medical supervision at a certified clinic.
- Titration: Dosages are slowly adjusted over weeks based on clinical response to avoid sedation or withdrawal.
- Typical Maintenance Dose: Often ranges between 80 mg and 120 mg per day. It is taken as a single daily dose.
For Chronic Pain Management
- Initial Dose: For opioid-naive patients, the starting dose is typically small, often 2.5 mg to 5 mg every 8 to 12 hours.
- Titration: Dose increases must occur slowly—no more frequently than every 3 to 5 days—because the drug builds up in the system over time.
Side Effects
Like all strong opioids, methadone can cause a wide spectrum of side effects, ranging from mild to life-threatening.
Common Side Effects
- Drowsiness, dizziness, or lightheadedness
- Nausea, vomiting, and severe constipation
- Increased sweating (diaphoresis)
- Dry mouth
- Weight gain or fluid retention
Serious Side Effects (Requires Immediate Medical Attention)
- Severe Respiratory Depression: Slow, shallow, or labored breathing.
- Severe Hypotension: A dangerous drop in blood pressure, leading to fainting or a feeling of extreme weakness.
- Adrenal Insufficiency: Nausea, vomiting, loss of appetite, worsening tiredness, or dizziness.
- Serotonin Syndrome: (When mixed with certain other medications) Agitation, hallucinations, rapid heart rate, muscle twitching, or shivering.
Critical Warnings and Black Box Precautions
Methadone carries several strict warnings due to its complex pharmacology and risks.
Respiratory Depression & Overdose Risk
Fatal respiratory depression can occur even at recommended doses, particularly when starting the drug or increasing the dose. Because methadone’s pain-relieving effects wear off much faster than the drug actually leaves the body, patients may mistakenly take more too soon, causing a toxic accumulation in the system.
QT Prolongation (Cardiac Arrhythmia)
Methadone can prolong the QT interval in the heart’s electrical cycle. This can lead to a rare, life-threatening heart rhythm disorder called Torsades de Pointes. Patients should undergo an electrocardiogram (ECG) before starting therapy and periodically during treatment.
Hazardous Drug Interactions
- CNS Depressants: Mixing methadone with alcohol, benzodiazepines (e.g., Xanax, Valium), or sleep aids can cause profound sedation, respiratory arrest, coma, and death.
- CYP450 Inhibitors/Inducers: Methadone is metabolized by liver enzymes (specifically CYP3A4, CYP2B6, and CYP2C19). Medications that inhibit these enzymes (like certain antifungals or antibiotics) can rapidly spike methadone levels, increasing overdose risks. Medications that induce these enzymes can drop methadone levels, causing sudden opioid withdrawal.
Neonatal Opioid Withdrawal Syndrome (NOWS)
Prolonged use of methadone during pregnancy can result in neonatal opioid withdrawal syndrome, a life-threatening condition for the newborn if not recognized and treated. However, for pregnant individuals with opioid use disorder, supervised methadone maintenance is still widely recommended over unsupervised withdrawal, as it stabilizes the pregnancy. Always coordinate treatment closely with a high-risk obstetrician.