methadone to morphine equivalence
| Drug | Dose | Methadone equivalent |
| ‘street’ heroin | 1g of powder | 50-60mg * |
| diamorphine | 10mg | 10mg |
| morphine | 10mg | 10mg |
| dihydrocodeine | 30mg | 3mg |
Aug 13 2022
Is morphine sulfate and methadone the same thing?
Methadose (methadone) is a cheap and effective treatment for severe chronic pain, but has serious risks for fatal overdose and drug dependence. Treats severe pain. Ms Contin (Morphine Sulfate) provides good long-term pain control without the need to take medicine frequently, but watch out for constipation.
How do you calculate morphine equivalents?
- Calculate the 24 hour current dose: 90mg q 12 = 180 mg Morphine/24 hours
- Use the oral to parenteral equianalgesic ratio: 30 mg PO Morphine = 10 mg IV Morphine
- Calculate new dose using ratios: 180/30 x 10 = 60 mg IV Morphine/24 hours or 2.5 mg/hour infusion
What is methadone compared to oxycodone?
Methadone is a fully synthetic opioid, and has a much longer half-life than oxycodone, which is a semi-synthetic opiate. You won’t feel the effects of methadone as quickly, but it’s still effective—it just takes longer to activate in your system. Methadone can also take longer to leave the system.
What is stronger Dilaudid or methadone?
methadone had longer, milder withdrawal, and dilaudid has shorter, more intense withdrawal. But the total pain is the same. A second thing, though, that pushes me to see you not having only ‘physical dependence’… those people do not have near the trouble tapering the drug as do addicts.
Can you predict equivalent doses?
it is not possible to accurately predict equivalent doses in most cases. This is especially true for street drugs where purity is notoriously variable. It is also problematic to convert from one drug to another when the half lives are not equivalent
Do you need expert advice before prescribing opioids?
It will be necessary to seek expert advice before prescribing in opioid abuse unless a prescriber is a clinician with specialist knowledge in this area.
Morphine Milligram Equivalents
Morphine equivalent dosing is employed to determine a patient’s cumulative intake of any opioids over 24 hours, in an attempt to avoid the higher dosages of opioids that are associated with higher risk of overdose and mortality.
Original reference
Von Korff M, Saunders K, et al. De facto long-term opioid therapy for noncancer pain. Clin J Pain. 2008; 24 (6):521-7.
Other references
Centers for Disease Control and Prevention. CDC grand rounds: prescription drug overdoses – a U.S. epidemic. 2012; 61 (01):10-13.
Why is buprenorphine not included in the calculator?
Buprenorphine is not included in the calculator because it is a partial agonist and morphine equivalent doses are uncertain. Please refer to the label for dosing parameters.
Can a patient be co-prescribed with benzodiazepines?
Is the patient co-prescribed benzodiazepines? Yes No
Does methadone cause cardiac arrhythmias?
In addition, methadone is associated with cardiac arrhythmias along with QT prolongation on the electrocardiogram.
Methadone Dosing Calculator
Factors that must be addressed during the conversion process include: Age of the patient or presence of coexisting conditions. Use additional caution with elderly patients (65 years and older), and in patients with liver, renal, or pulmonary disease.
P lease review these important points
Published equianalgesic ratios are considered crude estimates at best and therefore it is imperative that careful consideration is given to individualizing the dose of the selected opioid. Dosage titration of the new opioid should be completed slowly and with frequent monitoring.
Why do opioids overestimate potency?
When switching between opioids, equianalgesic conversions may overestimate the potency of the new opioid due to incomplete cross-tolerance. Incomplete cross-tolerance can occur due to variability in opioid binding. There is no evidence-based recommendation for an appropriate reduction. The American Pain Society guidelines and most pain experts recommend a dose reduction between 25-50% when converting between different opioids, 9, 11 with a consideration for little or no cross-tolerance reduction in patients with poorly controlled pain. 5
Is equianalgesic table the best?
While these equianalgesic tables are current the “best” solution, their limitations should be emphasized:
Is there a lack of data regarding equianalgesic conversions?
There is an overall lack of data regarding most equianalgesic conversions, and there is a significant degree of interpatient variability. For this reason, reasonable clinical judgment, breakthrough (rescue) opioid regimens, and dose titration are of paramount importance. reasonable clinical judgment, breakthrough (rescue) opioid regimens, …
How long does methadone last?
Cautions Unlike morphine, hydromorphone, or oxycodone, methadone has an extended terminal half-life of up to 190 hours. This half-life does not match the observed duration of analgesia (6-12 hours) after steady state is reached.
Can children take methadone?
Pediatrics With close monitoring by an experienced prescriber, methadone has been used safely in children, although the safety, effective ness, and the pharmacokinetics of methadone in patients below the age of 18 years have not been established by the Food and Drug Administration .
Is methadone safe for renal failure?
Compared to morphine, methadone is inexpensive, safe in renal failure, will provide a longer duration of action, and has a theoretic advantage in neuropathic pain, although the latter point has not been reliably demonstrated.
Is methadone a potent opioid?
Introduction Methadone, a potent opioid agonist, has many characteristics that make it useful for the treatment of pain when continuous opioid analgesia is indicated. Although available for decades, its use has gained renewed interest due to its low cost, inactive metabolites, and many routes of administration.
Is methadone lipophilic or morphine?
Methadone is highly lipophilic with rapid GI absorption and onset of action. It has a large initial volume of distribution with slow tissue release. Oral bioavailability is high, ~ 80%. Unlike morphine there are no active metabolites and biotransformation to an active drug is not required.
Does methadone have a long half life?
This long half-life can lead to increased risk for sedation and respiratory depression, especially in the elderly or with rapid dose adjustments. Rapid titration guidelines for other opioids do not apply to methadone.
Can you prescribe methadone rectally?
Prescribing Methadone is available in tablet, liquid and injectable forms; oral preparations can be used rectally. Parenteral routes include IV bolus dosing or continuous infusion. Any clinician with a Schedule II DEA license can prescribe methadone for pain; a special license is only required to prescribe methadone for the treatment of addiction.