What is methadone? Examining the use and side effects of Methadone

Drug addiction is one of the serious and complex issues that has spread widely all over the world and as a social and health problem, it causes many harmful effects on the individual and the society. In the past decades, many efforts have been made to deal with drug addiction and various drugs have been proposed to treat addiction and reduce its harm. One of the important and effective drugs in this field is the use of methadone as a therapeutic agent. Methadone drug is used as an alternative drug for famous drugs such as heroin, morphine, etc.

Pharmaceutical forms of methadone

Pharmaceutical forms of methadone include injectable solution 10 mg/ml, regular tablet 5 mg and 10 mg, dispersible tablet 40 mg, oral solution (syrup) 5 mg/5 ml and 10 mg/5 ml. The concentrated oral solution is 10 mg/ml. The choice of each of the medicinal forms of this drug depends on the type of disease and the doctor’s opinion.

Uses of methadone

This drug is used to treat moderate to severe pain and is a narcotic (addictive) drug. Methadone acts on specific centers in the brain to relieve pain and is also used to treat opioid use disorder as part of an approved treatment program. This process helps prevent withdrawal symptoms from stopping other opioids. The most important uses of methadone include pain management and detoxification, which can be used with the approval and prescription of a doctor.

Pharmacological effects and mechanism of action of Methadone drug

A narcotic agonist or analgesic inhibits opioid receptors and ascending pain pathways, thus altering the perception and response to pain. This process causes painlessness, respiratory depression and relaxation in the user. The effect of the pill starts in one hour and in 10-20 minutes for the injection type. This drug is metabolized in the liver through N-demethylation and finally excreted through urine.

Dosage of Methadone

Depending on your medication (pill, syrup, or ampoule), methadone is administered by injection into a vein, muscle, or subcutaneously. Dosage is based on your medical condition and your response to treatment. Visually inspect this medication for particulate matter or discoloration before use. For injection, disinfect the target area with alcohol and clean it with a wet tissue after injection. If this drug is given in the muscle or under the skin, it is important to change the injection site with each dose so that the injected areas do not experience swelling, pain, inflammation, etc.

Time to take methadone tablets

After taking methadone, if you experience nausea, talk to your doctor or pharmacist about ways to reduce it (such as lying down for 1-2 hours with as little head movement as possible). If you wait until the pain gets worse, the medication may not be as effective. If you have side effects such as restlessness, mental or emotional changes (including anxiety, sleep problems, suicidal thoughts), watery eyes, runny nose, nausea, diarrhea, sweating, sudden muscle pains, etc., after stopping the drug, see a doctor. do.

Precautions

This medicine may contain inactive ingredients that may cause allergic reactions or sensitivities, talk to your pharmacist for more details. Before using this medication, your medical history such as brain disorders (such as head injury, tumor, seizure), breathing problems (such as asthma, sleep apnea, chronic obstructive pulmonary disease), lung disease-COPD, kidney disease, liver disease, mental disorders or temperament (such as confusion, depression), personal or family history of substance use disorder (such as overuse or addiction to drugs or alcohol), stomach and intestinal problems (such as obstruction, constipation, diarrhea caused by infection) and… inform.

Methadone may cause conditions that affect your heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast or irregular heartbeats and other symptoms (eg, severe dizziness, fainting). Consult your doctor before taking methadone if you have certain heart conditions (such as heart failure, slow heart rate, QT prolongation on EKG) and family history of certain heart problems. According to the records, the doctor can prescribe the best medicine and prescription for you so that it does not threaten your health.

Some precautions of methadone

1. Opioids can cause sleep-related breathing disorders, including central sleep apnea (CSA) and sleep-related hypoxemia. Opioid use increases the risk of CSA in a dose-dependent manner. In patients presenting with CSA, consider tapering opioids using best-practice tapering methods.
2. The risks of addiction and abuse are increased in patients with a personal or family history of substance abuse or mental illness (such as major depression). However, the potential for these risks should not preclude prescribing appropriate pain management in any particular patient.
3. Serious, life-threatening, or fatal respiratory depression has been reported.
4. This drug will cause constipation in some patients, which can cause problems in patients with unstable angina and patients after myocardial infarction. Consider preventive measures (fluid softeners, increased dietary fiber) to reduce the likelihood of constipation.
5. Do not abruptly discontinue buprenorphine in patients who are physically dependent on opioids. When discontinuing treatment in a drug-dependent patient, gradually reduce the dose. Rapid tapering in an opioid-dependent patient may result in a withdrawal syndrome and return of pain.
6. Neonatal opioid withdrawal syndrome has been reported with long-term use during pregnancy.
7. Monitor for hypotension during initiation and dose titration. Use with caution in patients with hypovolemia, cardiovascular disease (including acute MI), or drugs that may significantly increase the hypotensive effects.
8. In patients with circulatory shock, treatment may cause vasodilation, which can further decrease cardiac output and blood pressure. Avoid treatment in patients with circulatory shock.
9. Life-threatening respiratory depression is more likely to occur in elderly, comatose, or debilitated patients because their pharmacokinetics or clearance may be altered compared with younger, healthier patients.
10. Serotonin syndrome may occur with concomitant administration of serotonergic agents. Monitor patients for symptoms of serotonin syndrome such as mental status changes, autonomic instability, neuromuscular changes, or gastrointestinal symptoms.

Methadone contraindications

1. Allergy to methadone (Methadone) or formulation components; Acute abdominal condition, toxic diarrhea, pseudomembranous colitis, respiratory depression, concomitant use of selegiline, hypercarbia, known or suspected gastrointestinal obstruction including paralytic ileus, asthma (acute), significant respiratory impairment
2. Acute pain or postoperative pain (pain that is mild or not expected to last).

Opioid Analgesia Risk Assessment and Reduction Strategy (REMS)

The Food and Drug Administration (FDA) has mandated REMS for these products to ensure that the benefits of opioid analgesics outweigh the risks of addiction and abuse. Under REMS requirements, pharmaceutical companies with approved opioid analgesic products must provide healthcare providers with REMS-compliant training programs. Physicians should provide patients with a REMS-compliant educational program regarding the safe use, serious hazards, storage, and disposal of these products with each prescription.

Life-threatening respiratory depression of methadone

1. Serious, life-threatening or fatal respiratory depression has occurred in some patients after taking the drug.
2. Monitor the patient for respiratory depression, especially when starting or after increasing the dose. Instruct patients to swallow tablets or capsules whole. Crushing, chewing, snorting, injecting or dissolving can cause the rapid release and absorption of a potentially fatal dose.
3. Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death.

Neonatal opiate withdrawal syndrome

1. Long-term use during pregnancy can lead to neonatal opioid withdrawal syndrome, which is life-threatening if not recognized and treated, and requires management based on protocols developed by neonatologists.
2. This syndrome appears as irritability, hyperactivity and abnormal sleep patterns, loud crying, tremors, vomiting, diarrhea and lack of weight gain.
3. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioids used, the duration of use, the time and amount of the mother’s last intake, and the amount of drug excretion by the infant.
4. If opioid use is required for a long period in a pregnant woman, inform the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment is available.

Methadone side effects

Nausea, vomiting, constipation, lightheadedness, dizziness, dry mouth, drowsiness and increased sweating are some of the side effects of Methadone. Tell your doctor if these side effects persist or worsen after you finish the medication or prescription. To prevent constipation, get enough dietary fiber, water and exercise, you may also need to take laxatives. Some serious side effects of methadone include stopping breathing during sleep (sleep apnea), restlessness, confusion, hallucinations, stomach and abdominal pain, difficulty urinating or frequent urination, symptoms of adrenal gland dysfunction (such as loss of appetite, fatigue). abnormal, weight loss) and…

1. Anticholinergic effects (dry mouth, palpitations, tachycardia)
2. Constipation, dizziness, mental fogginess or depression
3. Mental darkness or depression
4. Myocardial infarction
5. Cardiac arrest or coma
6. angina pectoris
7. nausea
8. itching, hives
9. being nervous
10. Stimulation

Drug interactions of methadone

Drug interactions may change how your medications work or increase your risk of serious side effects. Specific analgesics (opioid agonist-antagonist mixtures such as butorphanol, nalbuphine, pentazocine), naltrexone, sumidorphan. Taking MAO inhibitors with this drug may cause serious (possibly fatal) drug interactions. Do not use any MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobamide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during methadone treatment.

Most MAO inhibitors should also not be taken for two weeks before and after treatment with this drug. Ask your doctor when to start or stop taking this medicine. Also, some medications can affect how methadone is removed from your body, for example, St. John’s wort, azole antifungals (such as itraconazole), macrolide antibiotics (such as erythromycin), rifamycins (rifampin), drugs used to treat seizures (such as used carbamazepine) and… Also, the risk of serious side effects (such as slow or shallow breathing, drowsiness, and severe dizziness) may be increased if this drug is used with other products that also cause drowsiness or breathing problems.

1. Specific analgesics (opioid agonist-antagonist mixtures such as butorphanol, nalbuphine, pentazocine), naltrexone, sumidorphan
2. Taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobamide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine)
3. Drugs that reduce the effects of the drug, such as darunavir, deferasirox, enzalutamide, erdafitinib, etravirine, fosamprenavir, fosphenytoin, isavuconazonium sulfate, lopinavir, mitotane, nalmifene, naltrexone, nelfinavir, rifamycin derivatives, ritonavir, saquinavir, sarilumab, siltoximb, tipranavir, Tucilizumab

Taking methadone tablets during pregnancy and breastfeeding

No adequate and controlled studies in pregnant women are available. Untreated opioid addiction is associated with adverse obstetric outcomes such as low birth weight, preterm labor, and fetal death. Additionally, untreated opioid addiction often leads to continued or relapsed illicit opioid use. Neonatal opioid withdrawal syndrome (NOWS) is an expected and treatable consequence of long-term opioid use during pregnancy. Do not use any medicine without a doctor’s prescription during pregnancy.

Pregnant women with methadone maintenance programs can reduce the incidence of obstetric and fetal complications, neonatal morbidity and mortality, compared to women who use illegal (non-prescription) drugs. Untreated addiction to opioids during pregnancy is associated with adverse obstetric outcomes and serious side effects in the fetus and mother. These risks should be considered in women undergoing maintenance opioid addiction treatment. For women treated with pain severe enough to require daily, round-the-clock, long-term opioid therapy, treatment should be given during pregnancy only if the potential benefit justifies the serious risks to the fetus.

Methadone drug use and infertility

Chronic use of opioids may reduce fertility in women and men of reproductive potential. Reproductive function in men is also reduced by methadone treatment. Decreased volume of ejaculate and seminal vesicles and prostate secretions have been reported in methadone treated subjects. In addition, a decrease in serum testosterone levels and sperm motility and abnormalities in sperm morphology have also been reported.

Methadone storage conditions

Methadone should be stored at room temperature away from light and moisture. Keep this medicine out of the reach of children and animals.

The last word of methadone drug

In this article from the online positive pharmacy magazine, we investigated the role of methadone in the management of drug addiction and discussed some uses, precautions and contraindications of this drug. This drug is known as an effective solution in reducing harm related to drug use. Methadone drug has similar effects to drugs, but due to its specific characteristics, including reduced addiction and less unpleasant experience, it leads to a reduction of social and health harms related to drug use.

Site source: Medscape