
Even though it’s safer than some other narcotics,
your doctor should keep a close watch on you while you take methadone. Taking
it can lead to addiction or abuse.
Methadone Warnings
Methadone carries a black-box warning because it may cause serious or life-threatening breathing problems. The risk of breathing problems is highest during the first 72 hours of treatment and any time your dose is increased.
You should tell your doctor if you
have or have ever had asthma, slowed
breathing, chronic obstructive pulmonary disease
(COPD), or any other type of lung disease; a head injury; any
condition that increases pressure in your brain; or obstructive or central sleep apnea.
Also, you should watch for any signs of breathing problems, including slowed breathing, long pauses between breaths, or shortness of breath. This medication may also cause a rare heart problem known as a long QT interval. This condition can cause irregular heartbeat, fainting, or sudden death.
You should tell your doctor if you
or anyone in your family has or has ever had long QT syndrome.
Also, tell your healthcare provider
if you have ever had a slow or irregular heartbeat, heart disease, or low
levels of potassium or magnesium in your blood.
Call your doctor right away if you experience a pounding heartbeat, lightheadedness, dizziness, or fainting while taking methadone.
- Paralytic ileus (a condition where digested food doesn't move through the intestines)
- A blockage in your intestine
- An enlarged prostate
- Difficulty urinating
- Addison's disease (a condition where the adrenal gland doesn't work properly)
- Seizures
- Thyroid, pancreas, gallbladder, liver, or kidney disease
Pregnancy and Methadone
Methadone might harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while taking this medicine.Your baby may also develop life-threatening withdrawal symptoms after birth if you take methadone during pregnancy.
Methadone can pass into breast milk and may harm a breastfeeding baby, so talk to your doctor before breastfeeding while taking this medication.
Mechanism of action
The methadone abstinence syndrome, although qualitatively similar to that of morphine, differs in that the onset is slower, the course is more prolonged, and the symptoms are less severe. Some data also indicate that methadone acts as an antagonist at the N-methyl-D-aspartate (NMDA) receptor. The contribution of NMDA receptor antagonism to methadone's efficacy is unknown. Other NMDA receptor antagonists have been shown to produce neurotoxic effects in animals.
Absorptiom
Common Side Effects of Methadone
- Constipation
- Weakness
- Headache
- Nausea or vomiting
- Loss of appetite
- Weight gain
- Stomach pain
- Sore tongue
- Dry mouth
- Sweating
- Flushing
- Mood changes
- Difficulty urinating
- Vision problems
- Decreased sexual desire or ability
- Missed menstrual periods
- Difficulty falling asleep or staying asleep
- Seizures
- Itching, hives, or rash
- Hoarseness
- Pounding heartbeat
- Severe nervousness or restlessness
- Difficulty swallowing or breathing
- Extreme drowsiness
- Fainting
- Hallucinations (seeing or hearing things that do not exist)
- Swelling of the eyes, face, mouth, tongue, or throat
Methadone and Grapefruit
- St. John's wort
- Other narcotic pain drugs
- Antidepressants such as amitriptyline, amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin (Silenor), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil)
- Certain antifungals such as fluconazole (Diflucan), itraconazole (Onmel, Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend)
- Diuretics (water pills)
- Erythromycin (Erythrocin)
- Fludrocortisone
- Certain laxatives
- Sleeping pills or tranquilizers
- Medications for irregular heartbeat such as amiodarone (Cordarone, Pacerone, Nexterone), disopyramide (Norpace), dofetilide (Tikosyn), ibutilide (Corvert), flecainide, procainamide, and quinidine (Quinidex, in Nuedexta)
- Nicardipine (Cardene)
- Risperidone (Risperdal)
- Sertraline (Zoloft)
- Antihistamines
- Buprenorphine (Suboxone, in Zubsolv)
- Butorphanol
- Calcium channel blocking agents such as carbamazepine (Tegretol)
- Fluvoxamine (Luvox)
References
https://www.drugabuse.gov/sites/default/files/pdf/partb.pdf
http://www.who.int/entity/substance_abuse/activities/proposal_for_inclusion_of_buprenorphine_in_who_list_of_essential_medicines.pdf?ua=1
http://www.cesar.umd.edu/cesar/drugs/methadone.pdf
https://www.aafp.org/afp/2001/0615/p2404.pdf
https://bmchealthservres.biomedcentral.com/track/pdf/10.1186/s12913-018-3717-2
http://deadiversion.usdoj.gov/drug_chem_info/methadone/methadone.pdf
https://www.who.int/medicines/news/methadone-programme-tanzania/en/
https://medlineplus.gov/druginfo/meds/a682134.html
https://www.webmd.com/mental-health/addiction/what-is-methadone
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1070723/
0 Comments