LOFEXIDINE Drug Interactions: What You Need to Know

INTERACTIONS Methadone : Methadone and Lofexidine tablets both prolong the QT interval. ECG monitoring is recommended when used concomitantly. ( 7.1 )

Oral

Naltrexone : Concomitant use may reduce efficacy of oral naltrexone. ( 7.2 ) CYP2D6 Inhibitors : Concomitant use of paroxetine resulted in increased plasma levels of Lofexidine. Monitor for symptoms of orthostasis and bradycardia with concomitant use of a CYP2D6 inhibitor. ( 7.4 )

7.1 Methadone Lofexidine tablets and methadone both prolong the QT interval. ECG monitoring is recommended in patients receiving methadone and Lofexidine tablets concomitantly <span class="opacity-50 text-xs">[see Warnings and Precautions (5.2) , Clinical Pharmacology (12.3) ]</span> .

7.2 Oral Naltrexone Coadministration of Lofexidine tablets and oral naltrexone resulted in statistically significant differences in the steady-state pharmacokinetics of naltrexone. It is possible that oral naltrexone efficacy may be reduced if used concomitantly within 2 hours of Lofexidine tablets. This interaction is not expected if naltrexone is administered by non-oral routes <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> .

7.3 CNS Depressant Drugs Lofexidine tablets potentiate the CNS depressant effects of benzodiazepines and may potentiate the CNS depressant effects of alcohol, barbiturates, and other sedating drugs. Advise patients to inform their healthcare provider of other medications they are taking, including alcohol <span class="opacity-50 text-xs">[see Warnings and Precautions (5.3) ]</span> .

7.4 CYP2D6 Inhibitor - Paroxetine Coadministration of Lofexidine tablets and paroxetine resulted in a 28% increase in the extent of absorption of Lofexidine. Monitor for orthostatic hypotension and bradycardia when an inhibitor of CYP2D6 is used concomitantly with Lofexidine tablets <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> .

None. None. ( 4 )

AND PRECAUTIONS Risk of Hypotension, Bradycardia, and Syncope : May cause a decrease in blood pressure, a decrease in pulse, and syncope. Monitor vital signs before dosing and advise patients on how to minimize the risk of these cardiovascular effects and manage symptoms, should they occur. Monitor symptoms related to bradycardia and orthostasis. When using in outpatients, ensure that patients are capable of self-monitoring for signs and symptoms. Avoid use in patients with severe coronary insufficiency, recent myocardial infarction, cerebrovascular disease, or chronic renal failure, as well as in patients with marked bradycardia. ( 5.1 ) Risk of QT Prolongation : Lofexidine tablets prolong the QT interval. Avoid use in patients with congenital long QT syndrome. Monitor ECG in patients with electrolyte abnormalities, congestive heart failure, bradyarrhythmias, hepatic or renal impairment, or in patients taking other medicinal products that lead to QT prolongation. ( 5.2 )

Increased

Risk of CNS Depression with Concomitant use of CNS Depressant Drugs : Lofexidine tablets potentiate the CNS depressant effects of benzodiazepines and may potentiate the CNS depressant effects of alcohol, barbiturates, and other sedating drugs. ( 5.3 )

Increased

Risk of Opioid Overdose after Opioid Discontinuation : Patients who complete opioid discontinuation are at an increased risk of fatal overdose should they resume opioid use. Use in conjunction with a comprehensive management program for treatment of opioid use disorder and inform patients and caregivers of increased risk of overdose. ( 5.4 ) Risk of Discontinuation Symptoms : Instruct patients not to discontinue therapy without consulting their healthcare provider. When discontinuing therapy, reduce dose gradually. ( 5.5 )

5.1 Risk of Hypotension, Bradycardia, and Syncope Lofexidine tablets can cause a decrease in blood pressure, a decrease in pulse, and syncope <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) , Clinical Pharmacology (12.2) ]</span> . Monitor vital signs before dosing. Monitor symptoms related to bradycardia and orthostasis. Patients being given Lofexidine tablets in an outpatient setting should be capable of and instructed on self-monitoring for hypotension, orthostasis, bradycardia, and associated symptoms. If clinically significant or symptomatic hypotension and/or bradycardia occur, the next dose of Lofexidine tablets should be reduced in amount, delayed, or skipped. Inform patients that Lofexidine tablets may cause hypotension and that patients moving from a supine to an upright position may be at increased risk for hypotension and orthostatic effects. Instruct patients to stay hydrated, on how to recognize symptoms of low blood pressure, and on how to reduce the risk of serious consequences should hypotension occur (e.g., sit or lie down, carefully rise from a sitting or lying position). Instruct outpatients to withhold Lofexidine tablets doses when experiencing symptoms of hypotension or bradycardia and to contact their healthcare provider for guidance on how to adjust dosing. Avoid using Lofexidine tablets in patients with severe coronary insufficiency, recent myocardial infarction, cerebrovascular disease, chronic renal failure, and in patients with marked bradycardia. Avoid using Lofexidine tablets in combination with medications that decrease pulse or blood pressure to avoid the risk of excessive bradycardia and hypotension.

5.2 Risk of QT Prolongation Lofexidine tablets prolong the QT interval. Avoid using Lofexidine tablets in patients with congenital long QT syndrome. Monitor ECG in patients with congestive heart failure, bradyarrhythmias, hepatic impairment, renal impairment, or patients taking other medicinal products that lead to QT prolongation (e.g., methadone). In patients with electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia), correct these abnormalities first, and monitor ECG upon initiation of Lofexidine tablets <span class="opacity-50 text-xs">[see Dosing and Administration (2.1) , Adverse Reactions (6.1) , Special Populations (8.6 , 8.7) , Clinical Pharmacology (12.2) ]</span> .

5.3 Increased Risk of Central Nervous System Depression with Concomitant use of CNS Depressant Drugs Lofexidine tablets potentiate the CNS depressive effects of benzodiazepines and can also be expected to potentiate the CNS depressive effects of alcohol, barbiturates, and other sedating drugs. Advise patients to inform their healthcare provider of other medications they are taking, including alcohol. Advise patients using Lofexidine tablets in an outpatient setting that, until they learn how they respond to Lofexidine tablets, they should be careful or avoid doing activities such as driving or operating heavy machinery.

5.4 Increased Risk of Opioid Overdose after Opioid Discontinuation Lofexidine tablets are not a treatment for opioid use disorder. Patients who complete opioid discontinuation are likely to have a reduced tolerance to opioids and are at increased risk of fatal overdose should they resume opioid use.

Use

Lofexidine tablets in patients with opioid use disorder only in conjunction with a comprehensive management program for the treatment of opioid use disorder and inform patients and caregivers of this increased risk of overdose.

5.5 Risk of Discontinuation Symptoms Stopping Lofexidine tablets abruptly can cause a marked rise in blood pressure. Symptoms including diarrhea, insomnia, anxiety, chills, hyperhidrosis, and extremity pain have also been observed with Lofexidine tablets discontinuation. Instruct patients not to discontinue therapy without consulting their healthcare provider. When discontinuing therapy with Lofexidine tablets, gradually reduce the dose <span class="opacity-50 text-xs">[see Dosing and Administration (2.1) ]</span> . Symptoms related to discontinuation can be managed by administration of the previous Lofexidine tablet dose and subsequent taper.