- Prescription Drug Abuse Slideshow: Facts and Statistics
- OTC and Prescription Drug Abuse Slideshow Pictures
- Health Risks of Alcohol Abuse Slideshow Pictures
- What is methadone-oral tablet, and how does it work (mechanism of action)?
- What brand names are available for methadone-oral tablet?
- Is methadone-oral tablet available as a generic drug?
- Do I need a prescription for methadone-oral tablet?
- What are the side effects of methadone-oral tablet?
- What is the dosage for methadone-oral tablet?
- Which drugs or supplements interact with methadone-oral tablet?
- Is methadone-oral tablet safe to take if I'm pregnant or breastfeeding?
- What else should I know about methadone-oral tablet?
What is the dosage for methadone-oral tablet?
The initial dose of oral methadone in patients who require continuous pain control throughout the day can range from 2.5 to 10 mg given every 8 to 12 hours. Those who are seriously ill may need to be started at an oral dose of 10-40 mg given every 6-12 hours. The initial total daily dose for detoxification usually is higher, and this can range from 20 to 120 mg daily. The usual dose for methadone solution for injection when treating moderate to severe pain in patients who require continuous pain control is 2.5 to 10mg given as intravenous (I.V.), subcutaneous (SubQ) or intramuscular (I.M.) injection every 8-12 hours.
The conversion ratio from oral methadone to methadone given as an injection (I.V., SubQ) or I.M.) is 2:1. The total daily amount of methadone that a person is prescribed is not fixed, and it will depend on many factors including the severity of the pain, prior use of methadone, medications that are being taken concomitantly, the response to treatment and other factors that may be specific to a person. Therefore, each person has to be monitored carefully while receiving methadone. When stopping therapy, the dose of methadone should be gradually reduced in order to avoid withdrawal symptoms.
Which drugs or supplements interact with methadone-oral tablet?
Methadone when taken with drugs that slow brain function, such as alcohol and barbiturates (phenobarbital), can increase the effects of these drugs. Since methadone causes constipation, taking antidiarrheal medications such as diphenoxylate and atropine (Lomotil) and loperamide (Imodium) along with methadone can result in severe constipation. Drugs that block narcotic (opioid) receptors including pentazocine (Talwin), nalbuphine (Nubain), naloxone (Narcan), butorphanol (Stadol) and buprenorphine (Subutex) can lead to withdrawal symptoms.
Rifampin (Rifadin), barbiturates, carbamazepine (Tegretol), phenytoin (Dilantin), primidone and St. John's wort preparations can increase the liver's ability to metabolize (eliminate) methadone and reduce its blood concentration which could result in withdrawal side effects, while drugs such as erythromycin (E-Mycin, Eryc, Ery-Tab), clarithromycin (Biaxin, Biaxin XL), ketoconazole (Nizoral), and itraconazole (Sporanox) can decrease the liver's ability to metabolize methadone thereby increasing the side effects of this drug.
Anti-retroviral agents including abacavir (Ziagen), amprenavir (Agenerase), efavirenz (Sustiva), nelfinavir (Viracept), Nevirapine (Viramune, Viramune XR), Ritonavir (Norvir), and lopinavir/ ritonavir (Kaletra) have been shown to decreased the blood levels of methadone making it necessary to adjust the dose of methadone to prevent narcotic withdrawal effects.
Some drugs that slow the heart rate for example, dofetilide (Tikosyn), procainamide (Pronestyl, Procan-SR), quinidine, and sotalol ((Betapace), as well as laxatives and diuretics that cause low magnesium or low potassium in the body, for example, furosemide (Lasix), can cause rare serious and fatal irregular heartbeats.
Quick GuideAddicted to Pills: The Health Risks of Drug Abuse
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?
Use the pill identifier tool on RxList.