Lorbrena and Methadose (Methadone Tablets)

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Lorlatinib may reduce the blood levels of methadone, which may make the medication less effective in treating your condition. Additionally, if you have been receiving treatment with methadone, adding lorlatinib may cause you to experience unpleasant withdrawal symptoms such as watery eyes, runny nose, sneezing, yawning, excessive sweating, goose bumps, fever, chills, flushing, restlessness, irritability, anxiety, depression, pupil dilation, tremor, rapid heart beat, body aches, involuntary twitching and kicking, abdominal cramping, loss of appetite, nausea, vomiting, diarrhea, and weight loss. On the other hand, if you have been receiving both medications, discontinuing lorlatinib may increase the blood levels of methadone, which could lead to an overdose. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

MONITOR CLOSELY: Coadministration with inducers of various CYP450 isoenzymes may decrease the plasma concentrations of methadone, which is metabolized by CYP450 3A4, 2B6, 2C19, 2C9, and 2D6. Reduced analgesic efficacy or withdrawal symptoms may occur in patients maintained on methadone following the addition of an inducer. Conversely, discontinuation of the inducer may increase methadone plasma concentrations and potentiate the risk of overdose and fatal respiratory depression. The interaction has been reported with several moderate and potent inducers including rifampin, phenytoin, phenobarbital, nevirapine, and efavirenz. In one report, evidence of withdrawal was observed in 21 of 30 patients maintained on methadone who received rifampin for tuberculosis, compared to zero out of 26 who received other antituberculous agents. In a study of 11 patients on stable methadone maintenance treatment, mean methadone peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 48% and 57%, respectively, following initiation of antiretroviral therapy containing efavirenz 600 mg once a day. Nine patients developed symptoms consistent with methadone withdrawal an average of 8 to 10 days after start of efavirenz, which required a 22% mean increase in methadone dosage. In a similar study with nevirapine given at 200 mg once daily for 2 weeks followed by 200 mg twice daily, the reduction in mean methadone Cmax and AUC was 36% and 52%, respectively, in 8 patients stabilized on methadone treatment. Withdrawal symptoms occurred in six patients 8 to 10 days after start of nevirapine, and methadone dosage was subsequently increased an average of 16%. Dosage increases of up to 100% and eventual discontinuation of the non-nucleoside reverse-transcriptase inhibitor have also been described in some reports.

MANAGEMENT: Caution is advised if methadone is prescribed with CYP450 2B6, 2C19, 2C9 and/or 3A4 inducers. Pharmacologic response to methadone should be monitored more closely whenever an inducer is added to or withdrawn from therapy, and the dosage adjusted as necessary.

Lorbrena

Generic Name: lorlatinib

Brand name: Lorbrena

Synonyms: n.a.

What is Lorbrena?

Methadose (Methadone Tablets)

Generic Name: methadone

Brand name: Methadose, Dolophine, Methadose Sugar-Free, Diskets

Synonyms: Methadose (Oral Concentrate), Methadose

What is Methadose (Methadone Tablets)?