METHADONE and TRAMADOL

Methadone

Mechanism of Action

It is predominantly an agonist of the u-receptor and mimics natural opioids, enkephalins, and endorphins. It may also impact the release of other neurotransmitters, including acetylcholine, norepinephrine, substance P, and dopamine.

Its analgesic and antitussive effects, respiratory depression, drowsiness, decreased intestinal motility, increased biliary tone, hormone modulation, increased release of prolactin and growth hormone, miotic pupils, nausea, and hypotension are only a few of its other effects.

Indication

• Management of severe pain.
• Detoxification treatment of opioid addiction

Dose

Initially 10-30 mg daily and up to 40 mg daily.

Contraindication

Individuals with paralytic ileus, acute bronchial asthma, respiratory depression, or hypercarbia

Side Effect

Anxiety, nervousness, restlessness, insomnia, weakness, drowsiness, dry mouth, nausea, vomiting, diarrhea, constipation, loss of appetite, decreased sex drive, impotence, difficulty having an orgasm, shallow breathing, hallucinations, confusion, chest pain, dizziness, fainting, fast or pounding heartbeat, trouble breathing, lightheadedness, fainting.

Nursing Consideration

• When compared to its peak therapeutic impact, methadone's peak respiratory depressive effect occurs later and lasts longer. 
• A high level of opioid tolerance does not rule out the potential of an accidental or intentional overdose on methadone.
• Deaths have been reported during the switch from long-term, high-dose treatment with other opioid agonists to methadone as well as during the beginning of the methadone addiction treatment in patients who had previously abused long-term, high-dose treatments with other agonists.
• The potential for toxicity to last longer is increased by repeated administration, which causes methadone to be held in the liver and then released gradually.
• Especially when combined with other medications, methadone has a limited therapeutic index.
• Methadone and syrup that has been preserved with hydroxybenzoate esters may not mix well.

Tramadol

Mechanism of Action:

• It is a centrally acting opiate receptor agonist that prevents norepinephrine and serotonin from being absorbed, indicating both opioid and nonopioid pain alleviation mechanisms.
• A weak agonist of the opioid receptor, tramadol. It's u-opioid receptor-binding
• It functions as an inhibitor of serotonin-norepinephrine reuptake.

Indication:

Moderate to severe pain

Dose:

Adult: 50mg-100mg bid or tid, maxmium dose not exceeding 400mg / d * ay

Child: 1-2mg/kg/dose in 4-6 times a day

Contraindication:

Hypersensitivity, acute CNS intoxication due to alcohol, acute atttack of asthma, head injury

Side Effect:

Drowsiness, dizziness, vertigo, fatigue, somnolence, restlessness, euphoria, confusion, seizures, nausea, vomiting, constipation, xerostomia, dyspepsia, diarrhea, urinary retention, menopausal symptoms, palpitations, vasodilation, rash, visual disturbances, sweating, anaphylactic reaction, withdrawal syndrome

Nursing Consideration

• Keep an eye on your vitals and look out for orthostatic hypotension or indications of CNS depression.
• If S&S of hypersensitivity occur, stop taking the medication and let your doctor know.
• Evaluate bowel and bladder function; describe urinary retention or frequency.