Methadone Hydrochloride
This medication is a Schedule II drug.
Former Brand Name: Methadose
Generic Only
Common Dosage Forms:
Tablets: 5 mg, 10 mg, 40 mg
Oral solution: 5 mg/5 mL, 10 mg/5 mL
Oral concentration: 10 mg/mL
Injection: 10 mg/mL in 20 mL vials
FDA Indications/Dosages:
For the relief of severe pain: The usual adult dosage is 2.5-10 mg every 3-4 hours as needed. Dosage should be adjusted to the individual patient’s needs and may exceed the usual dosage recommendations in cases of severe pain or in those patients who are tolerant to narcotics.
For detoxification treatment of narcotic addiction: An initial dose of 15-20 mg is usually adequate to treat withdrawal symptoms. 40 mg is an average maintenance dose. Doses may be decreased every 2 days as the patient tolerates. Administration longer than 3 weeks is considered maintenance treatment.
For the temporary maintenance treatment of narcotic addiction: Patients dosage during maintenance treatment should be individualized and should be adequate to keep withdrawal symptoms to a tolerable level.
Pharmacology/Pharmacokinetics: Methadone hydrochloride is a synthetic opiate analgesic with actions similar to morphine. Analgesia is produced centrally via action on the central opiate receptors. Absorption of methadone after an oral dose is excellent with peak concentrations occurring in 4 hours. The elimination half-life of methadone is 24-36 hours. Metabolism occurs primarily via liver N-demethylation. Protein binding is strong and occurs at about 90% of the bioavailable dose. Release from protein binding sites is slow and accounts for the prolonged activity of methadone.
Drug Interactions: Severe adverse effects occur when used with MONOAMINE OXIDASE INHIBITORS. Rifampin may reduce plasma levels of methadone and precipitate withdrawal symptoms. Pentazocine, a narcotic antagonist, may precipitate withdrawal symptoms in patients taking methadone. May produce additive CNS depressant effects is used with other CNS depressants.
Contraindications/Precautions: Methadone tablets are contraindicated for injection use. Physicians should be careful not to confuse normal periods of anxiety with those of narcotic withdrawal. Use with extreme caution in patients with head injuries. Use with caution in patients having an acute asthma attack, in patients with chronic obstructive pulmonary disease or cor pulmonale, and in patients with respiratory depression, hypoxia, or hypercapnia. Hypotension may occur in patients who are volume-depleted or who are currently taking certain CNS depressants. OPIOIDS CAN BE ADDICTIVE, ABUSED, AND MISUSED WHICH CAN LEAD TO OVERDOSE AND DEATH. SERIOUS, LIFE-THREATENING RESPIRATORY DEPRESSION MAY OCCUR. ACCIDENTAL EXPOSURE CAN BE FATAL, ESPECIALLY IN CHILDREN. USE IN PREGNANCY CAN CAUSE NEONATAL WITHDRAWAL SYNDROME. CONCOMITANT USE WITH BENZODIAZEPINES, ALCOHOL, OR OTHER CNS DEPRESSANTS CAN RESULT IN RESPIRATORY DEPRESSION, COMA, AND DEATH. Pregnancy Category Established.
Adverse Effects: The most common adverse effects include dizziness, drowsiness, lightheadedness, nausea, vomiting, and sweating.
Patient Consultation:
May cause drowsiness. Use caution while operating machinery or when mental alertness is requires.
Avoid alcohol while taking this medication.
May take with food or milk to avoid GI upset.
WARNING: This medication may be habit-forming.
This prescription cannot be refilled.
Store in a cool, dry place away from sunlight and children.
Contact a physician if the above side effects are severe or persistent.
If a dose is missed, skip it and return to normal dosing schedule. Do not exceed prescribed dosage.
